And another key thing to note ... the NAD system is now at an awkward state of optimisation - something I have experienced over and over again, throughout the years. The quality is now good enough, when everything is correctly organised, for the sound to have that 'magical' quality that so many people chase - but that level of "refinement" is very delicate, fragile; it's not robust in of itself. That is, a single element not in effective alignment means that the conjuring does not happen, and of course that is disappointing, and means one can feel quite negative about the whole exercise - an intense round of examining everything ensues, sometimes with great frustration when no cause pops up immediately, but usually with great relief when the problem is finally tracked down - the diagnosis is the hard bit, the solution is usually quite trivial to implement!
The longer term aim is to move the stability of the system playback quality to the point where the necessary quality "robustness" is well and truly in place, and can withstand degradation of minor aspects without causing the auditory illusion to fail. I have spent large amounts of effort with the many audio experiments over the years trying to establish better control of this, and will strongly emphasis that this is crucial - the frustration of hearing the quality fall back below the necessary standard is very wearing - in my earliest attempts, years ago, it led me to completely give up on trying to achieve high quality sound for a very long time, the disappointments wore me down ...
Sunday 27 December 2015
Friday 25 December 2015
"The essential characteristic of the original signal" ... ?
Referring to a recording, of course. I just saw this phrase commented upon in a thread on an audio forum, its significance or meaning pooh-poohed ...
However, a competent playback system does allow this to emerge, in usually glorious ways! For someone who has never experienced this occurring it might seem almost magical, and in many ways it is remarkable, because it demonstrates the ability of the combination of ear and brain to decipher, unravel a consistent picture of a sound event in a fashion which minimises disturbing or unwanted aural artifacts not relevant to the musical performance. Especially on very poor, ancient recordings, full of detritus - on a typical, ambitious hifi system these will sound absolutely appalling, completely unlistenable to; every defect in the sound will be highly magnified, and will overwhelmingly dominate the listening experience - subjectively !!
Are we listening to the "essential characteristic of the original signal" in that situation? Of course not, our hearing is so distracted by the "noise" and "distortion" that accompanies the "signal", the musical event, that there is almost no chance of relating in an enjoyable way to the latter. So, what to do about that? Some of the options are: never listen to that recording; or, filter out by brute force frequency response manipulation, in the replay chain, what seems to be the worst unpleasantness; or ... raise the standard of the replay mechanism to the point that the human hearing mechanism is fed enough relatively clean information, allowing the ear/brain to do vital, internal, in the brain, filtering, without conscious effort. Even though the last choice may seem fanciful to many, it in fact is done all the time in the "real world" - a good example is listening to a musician busker on a busy street, performing with no sound reinforcing gear, having huge amounts of unrelated racket 'interfering' with the musical sound. The "essential characteristic of the original signal" is very obvious here; some passing by may completely ignore the performance, be oblivious to it, but others will have no trouble "tuning in" to what's important to them at that moment, and enjoy the efforts of the musician.
This should be the aim of quality audio reproduction, and is always achievable. The integrity of the production of the "art" of the music is retained in recordings, and it is only a matter of raising the standard of the replay chain to the point where one's hearing is able to distinguish the "essential characteristics" without conscious effort - this is the essence of the Art of Audio Conjuring!
However, a competent playback system does allow this to emerge, in usually glorious ways! For someone who has never experienced this occurring it might seem almost magical, and in many ways it is remarkable, because it demonstrates the ability of the combination of ear and brain to decipher, unravel a consistent picture of a sound event in a fashion which minimises disturbing or unwanted aural artifacts not relevant to the musical performance. Especially on very poor, ancient recordings, full of detritus - on a typical, ambitious hifi system these will sound absolutely appalling, completely unlistenable to; every defect in the sound will be highly magnified, and will overwhelmingly dominate the listening experience - subjectively !!
Are we listening to the "essential characteristic of the original signal" in that situation? Of course not, our hearing is so distracted by the "noise" and "distortion" that accompanies the "signal", the musical event, that there is almost no chance of relating in an enjoyable way to the latter. So, what to do about that? Some of the options are: never listen to that recording; or, filter out by brute force frequency response manipulation, in the replay chain, what seems to be the worst unpleasantness; or ... raise the standard of the replay mechanism to the point that the human hearing mechanism is fed enough relatively clean information, allowing the ear/brain to do vital, internal, in the brain, filtering, without conscious effort. Even though the last choice may seem fanciful to many, it in fact is done all the time in the "real world" - a good example is listening to a musician busker on a busy street, performing with no sound reinforcing gear, having huge amounts of unrelated racket 'interfering' with the musical sound. The "essential characteristic of the original signal" is very obvious here; some passing by may completely ignore the performance, be oblivious to it, but others will have no trouble "tuning in" to what's important to them at that moment, and enjoy the efforts of the musician.
This should be the aim of quality audio reproduction, and is always achievable. The integrity of the production of the "art" of the music is retained in recordings, and it is only a matter of raising the standard of the replay chain to the point where one's hearing is able to distinguish the "essential characteristics" without conscious effort - this is the essence of the Art of Audio Conjuring!
Wednesday 23 December 2015
A More Ambitious Upgrade - Part 13
A cautionary tale ...
This one is against me ... it's happened to me many times in this audio game over the years, and us humans being the way we're made, it's so easy to stumble into making the same error, over and over again - a little bit of success encourages a step too far, too fast ... we just want a bit more of that satisfying success, to keep feeding the drip ...
Which is to say that I overdid the dressing of the internal cables I mentioned in the previous episode, in the interim. Let's just make it a bit better, why not, was the thought. Trouble was, I was disturbing the stable physical equilibrium of those cables, established over a long period of time - and the result was a deadening of the sound, I had definitely lost something! Trying a number of recordings to check ... no, I had gone backwards, by a good margin.
Luckily, a good guess and just effectively reversing one of those "improvements" made a substantial difference - I was now back in much better territory in quality terms. So, I will proceed far more carefully with further experiments in refining the cabling layout; the quality of the sound is now such that a single wrong decision in this area can be markedly audible ...
Update: Hooray! Undid a few more of those wrong moves, a bit more fine tuning of alignment of the cables ... and, I can confidently say, we have conjuring!!
An ex-library CD, Vaughan Williams, Fantasia on a Theme by Tallis, 1976, Boult and the LPO, is working its magic - low level strings are special, lovely "bloom" to the sound, deep, rich resonance from the double basses; one can just fall into the sound ... this is what one is after ...
This one is against me ... it's happened to me many times in this audio game over the years, and us humans being the way we're made, it's so easy to stumble into making the same error, over and over again - a little bit of success encourages a step too far, too fast ... we just want a bit more of that satisfying success, to keep feeding the drip ...
Which is to say that I overdid the dressing of the internal cables I mentioned in the previous episode, in the interim. Let's just make it a bit better, why not, was the thought. Trouble was, I was disturbing the stable physical equilibrium of those cables, established over a long period of time - and the result was a deadening of the sound, I had definitely lost something! Trying a number of recordings to check ... no, I had gone backwards, by a good margin.
Luckily, a good guess and just effectively reversing one of those "improvements" made a substantial difference - I was now back in much better territory in quality terms. So, I will proceed far more carefully with further experiments in refining the cabling layout; the quality of the sound is now such that a single wrong decision in this area can be markedly audible ...
Update: Hooray! Undid a few more of those wrong moves, a bit more fine tuning of alignment of the cables ... and, I can confidently say, we have conjuring!!
An ex-library CD, Vaughan Williams, Fantasia on a Theme by Tallis, 1976, Boult and the LPO, is working its magic - low level strings are special, lovely "bloom" to the sound, deep, rich resonance from the double basses; one can just fall into the sound ... this is what one is after ...
The only real problem to solve in Audio, is Attitude
Problem, what problem? Some people might claim that everything is known to made reproduction of recordings as good as one could want - and in one sense they are right. But, if that's the case, why do so many systems, even those which are expensive and lavishly indulged in in terms of time and effort, sound very little like the "real thing", or just downright weird? Of course there are some extremely competent audio systems around, but they're thin on the ground, they stand out as being 'special' when one comes across them!
So, the "problem" is that one can't assemble an audio system from standard, off the shelf components and have it "sound good" - every time. To counter that, my experience over many decades, is that just about every assembly of sound gear, no matter how inexpensive, can be made to come up to, tweaked to an acceptable standard, and with extra effort be evolved into a mechanism that produces highly satisfying audio, and, yes, even conjures ...
What is clear, something recently even more strongly confirmed, is that there is very little desire to think beyond the standard cliches of audiophile think: "it's all about the frequency response"; "loudspeakers are what cripples the sound no matter what"; "huge effort must be put into creating a perfect acoustic environment for the audio equipment"; etc ... but a little thought puts these ideas into better perspective: an actual musical instrument or voice of a person in the room or any natural, non-reinforced sound doesn't require any of these sort of shenanigans, it will still have the impact of the "real thing", every time, irrespective of how casually the sound is produced, and how non attentively one listens to it. And the latter is my experience of competent playback: when it works well there is the same impact as hearing 'natural' sounds, no, absolutely zero, excuses or allowances have to be made for the fact that it is "only a recording" ...
It's easy to see that the attitude of the majority in audio land doesn't echo this thinking at all; firstly by reading what they have to say about things, and secondly by listening to what the vast majority of systems produce, the acoustic end result. Sometimes spectacular in a circus-like manner, often disappointing, irritating, fatiguing, uninteresting to listen to - nearly always sounding like a "hifi system", very rarely they are convincing.
But there is a solution ... just get a few people thinking that there may be a smarter way, which in essence is to view the business of reproducing sound from a recording as a process which has to have minimal flaws in every aspect, every area, to get a worthwhile result. Yes, people worry now about "flaws", but they're usually the 'wrong' flaws - they are of low importance, they matter little in the quest to produce an illusion that the ear/brain combination can believe in ... it's only a shift in attitude that's actually required, to focus on the key flaws that make the crucial difference in the quality of the sound that's heard.
So, the "problem" is that one can't assemble an audio system from standard, off the shelf components and have it "sound good" - every time. To counter that, my experience over many decades, is that just about every assembly of sound gear, no matter how inexpensive, can be made to come up to, tweaked to an acceptable standard, and with extra effort be evolved into a mechanism that produces highly satisfying audio, and, yes, even conjures ...
What is clear, something recently even more strongly confirmed, is that there is very little desire to think beyond the standard cliches of audiophile think: "it's all about the frequency response"; "loudspeakers are what cripples the sound no matter what"; "huge effort must be put into creating a perfect acoustic environment for the audio equipment"; etc ... but a little thought puts these ideas into better perspective: an actual musical instrument or voice of a person in the room or any natural, non-reinforced sound doesn't require any of these sort of shenanigans, it will still have the impact of the "real thing", every time, irrespective of how casually the sound is produced, and how non attentively one listens to it. And the latter is my experience of competent playback: when it works well there is the same impact as hearing 'natural' sounds, no, absolutely zero, excuses or allowances have to be made for the fact that it is "only a recording" ...
It's easy to see that the attitude of the majority in audio land doesn't echo this thinking at all; firstly by reading what they have to say about things, and secondly by listening to what the vast majority of systems produce, the acoustic end result. Sometimes spectacular in a circus-like manner, often disappointing, irritating, fatiguing, uninteresting to listen to - nearly always sounding like a "hifi system", very rarely they are convincing.
But there is a solution ... just get a few people thinking that there may be a smarter way, which in essence is to view the business of reproducing sound from a recording as a process which has to have minimal flaws in every aspect, every area, to get a worthwhile result. Yes, people worry now about "flaws", but they're usually the 'wrong' flaws - they are of low importance, they matter little in the quest to produce an illusion that the ear/brain combination can believe in ... it's only a shift in attitude that's actually required, to focus on the key flaws that make the crucial difference in the quality of the sound that's heard.
Saturday 19 December 2015
A More Ambitious Upgrade - Part 12
Are we there yet ... well, if not it's now mighty, mighty close ... last round I mentioned bypassing the amplifier's speaker relays, and in between I did so in a quick and dirty way - the sound appeared to improve, but I was still not 100% comfortable with the overall result; I didn't feel that it was worthwhile yet to do some tests, removing the bypass and comparing that with the kludge included ... something more needed to be done ...
One thing that was always on the list was the typical rat's nest of wiring inside the amp, tying all the modules and bigger lumps of hardware together electrically. The NAD was far, far better than many in this regard - nearly all the circuitry resides on a single, large circuit board. But, the remaining discrete wiring was the usual mess one finds in audio gear, roughly and loosely tied in bundles in a couple of places - I hadn't done anything yet to improve this because the unit had been so impressive so far ... was the remaining lack of "conviction" in the sound due to this ?? In particular, low level orchestral music was not there yet ...
So, I did a round of stabilising and separating the strands of connecting wire - in simple terms, making sure that any low amplitude vibrating of wires was minimised in level and impact. Only part way through this exercise, but for now let's see what that's got us ...
Ah-hah!! Significant lift in quality, now essentially have 'invisible' speakers, the system generates a deeply immersive sound field, and conveys a convincing sense of the performers doing their thing to the far end of the house, on an aggressive, messy recording. The sense of conjuring is very strong, and perhaps only a little more tweaking will be required now for a rock solid illusion to be always on tap.
Soon I will make some further recordings, done in a more careful way, of the system's reproduction that hopefully will convey a better sense of what I'm mentioning ...
One thing that was always on the list was the typical rat's nest of wiring inside the amp, tying all the modules and bigger lumps of hardware together electrically. The NAD was far, far better than many in this regard - nearly all the circuitry resides on a single, large circuit board. But, the remaining discrete wiring was the usual mess one finds in audio gear, roughly and loosely tied in bundles in a couple of places - I hadn't done anything yet to improve this because the unit had been so impressive so far ... was the remaining lack of "conviction" in the sound due to this ?? In particular, low level orchestral music was not there yet ...
So, I did a round of stabilising and separating the strands of connecting wire - in simple terms, making sure that any low amplitude vibrating of wires was minimised in level and impact. Only part way through this exercise, but for now let's see what that's got us ...
Ah-hah!! Significant lift in quality, now essentially have 'invisible' speakers, the system generates a deeply immersive sound field, and conveys a convincing sense of the performers doing their thing to the far end of the house, on an aggressive, messy recording. The sense of conjuring is very strong, and perhaps only a little more tweaking will be required now for a rock solid illusion to be always on tap.
Soon I will make some further recordings, done in a more careful way, of the system's reproduction that hopefully will convey a better sense of what I'm mentioning ...
Monday 14 December 2015
Yes, Virginia, it is like cleaning a window ...
It has become a cliche that improving playback sound is like having a clearer 'window' onto the recording, but, that remains a very apt analogy - sorry!! Achieving convincing, realistic recreation of a recorded musical event requires that the listener focuses only on the scene beyond the window - the latter representing the mechanism of the playback system, and the former being the actual 'data' encoded on the recording. A window that is dirty to some degree, or that distorts the image of what is on the other side can be largely ignored depending upon one's mood, and especially if the landscape beyond is already well known ... but removing the glass from that window, suddenly, will be quite noticeable, or dramatic, or even an epiphany ...
If an individual is content to always observe the world through that lesser window, oblivious to its effect, then that's fine - but if one were to be exposed to the "reality" beyond the imperfect glass barricade, then a burning desire to never be aware of that window lessening the impact of what one is seeing will form in many people. That it is impossible to actually eliminate the window may be part of the deal - you always require a playback system to experience recorded music - but your awareness of any filtering effect should be as close to zero as possible.
Thus, the exercise is to make the window as "perfect" as possible. And there are many ads of window cleaners where the punchline is that a person walks into the glass, not picking there is an "illusion" of nothing being in his way ... this is what one is after in audio - and, fortunately, it's very achievable ...
A large part of the "battle" in getting the glass 'transparent' enough is not understanding what audible artifacts are due to the glass, not realising that supposedly bad recordings, say, come across that way because the mind is struggling to make sense of the fine detail beyond the imperfect pane - many times it's easier to give up, mentally, and simply decide that the music is so flawed in the recording that nothing can be done about it ... but, nothing could be further from the truth ...
And so a key first step is learning to recognise what the imperfect window is doing to what you're perceiving: luckily, in the visual area everyone can easily adjust the focus of their eyes so that they "look" at the dirt on the window, the scene beyond is blurred out. People can use various ways, intuitive most of the time, to register what's wrong with the glass, being able to completely ignore what is actually seen through the pane - and then clean up and correct the window. Unfortunately, in the aural area, most people are not so well attuned to what's going on, and haven't learnt to switch, shift their focus on the sounds in what they hear.
One needs to be able to "see" the dirt in the playback, and know it's not part of the recording, the scene beyond, itself. This can be learnt, and once acquired, like riding a bike, never goes away. Then, you will motivated to fix the problem, and ,be far better equipped to make the right moves in sorting things out ...
If an individual is content to always observe the world through that lesser window, oblivious to its effect, then that's fine - but if one were to be exposed to the "reality" beyond the imperfect glass barricade, then a burning desire to never be aware of that window lessening the impact of what one is seeing will form in many people. That it is impossible to actually eliminate the window may be part of the deal - you always require a playback system to experience recorded music - but your awareness of any filtering effect should be as close to zero as possible.
Thus, the exercise is to make the window as "perfect" as possible. And there are many ads of window cleaners where the punchline is that a person walks into the glass, not picking there is an "illusion" of nothing being in his way ... this is what one is after in audio - and, fortunately, it's very achievable ...
A large part of the "battle" in getting the glass 'transparent' enough is not understanding what audible artifacts are due to the glass, not realising that supposedly bad recordings, say, come across that way because the mind is struggling to make sense of the fine detail beyond the imperfect pane - many times it's easier to give up, mentally, and simply decide that the music is so flawed in the recording that nothing can be done about it ... but, nothing could be further from the truth ...
And so a key first step is learning to recognise what the imperfect window is doing to what you're perceiving: luckily, in the visual area everyone can easily adjust the focus of their eyes so that they "look" at the dirt on the window, the scene beyond is blurred out. People can use various ways, intuitive most of the time, to register what's wrong with the glass, being able to completely ignore what is actually seen through the pane - and then clean up and correct the window. Unfortunately, in the aural area, most people are not so well attuned to what's going on, and haven't learnt to switch, shift their focus on the sounds in what they hear.
One needs to be able to "see" the dirt in the playback, and know it's not part of the recording, the scene beyond, itself. This can be learnt, and once acquired, like riding a bike, never goes away. Then, you will motivated to fix the problem, and ,be far better equipped to make the right moves in sorting things out ...
Saturday 12 December 2015
A More Ambitious Upgrade - Part 11
Some parameters relevant to the posted recordings of the NAD system playing:
As a reference for comparisons, other YouTube clips with the actual source material are The Faces - That's All You Need - YouTube and Jimmy McCracklin, EVERYBODY ROCK - YouTube.
The NAD amp uses relays driven by protection circuitry to connect to speakers, delayed closing of contacts on switch on, etc - and I was hoping that these wouldn't prove to be a quality bottleneck. Unfortunately, even though earlier listening didn't show any major issues this is ever more becoming noticeable, as improvements elsewhere make it easier to pick this happening - especially on pre-WWII recordings, which so easily descend into sounding like AM radio broadcasts, the harsh edge that typically vocals acquire when poor connections are a factor was clearly evident. This was easily tested by switching off the amp while music was playing, then switching back on again some seconds later, cleaning the contacts temporarily - the natural sweetness of the voices returns, only to slowly degrade with continuing playing of the track.
Hard wiring, bypassing the switch contacts is a permanent solution, from previous experience; but I lose the protection mechanism, plus have possible power on thumps through the speakers. Anyway, I will use this method for now to confirm that what I'm hearing is directly caused by the particular contacts - and then decide what to do about it, long term ...
- Room is approx. 7 x 4 metres, with sloping ceiling whose height varies from 2.5 to 3.5 metres lengthways
- Speakers facing shorter end of room, about 2.5 metres from that end, LH speaker about 0.5 metre from side wall
- As already mentioned, single microphone 2 metres behind RH speaker
- The room, a work room, is extremely cluttered, full of hard and soft surfaces, carpet on floor
- Deliberately started part way through track so that the the sound of the room and noise levels could be picked up during the gap between the the two tracks captured
As a reference for comparisons, other YouTube clips with the actual source material are The Faces - That's All You Need - YouTube and Jimmy McCracklin, EVERYBODY ROCK - YouTube.
The NAD amp uses relays driven by protection circuitry to connect to speakers, delayed closing of contacts on switch on, etc - and I was hoping that these wouldn't prove to be a quality bottleneck. Unfortunately, even though earlier listening didn't show any major issues this is ever more becoming noticeable, as improvements elsewhere make it easier to pick this happening - especially on pre-WWII recordings, which so easily descend into sounding like AM radio broadcasts, the harsh edge that typically vocals acquire when poor connections are a factor was clearly evident. This was easily tested by switching off the amp while music was playing, then switching back on again some seconds later, cleaning the contacts temporarily - the natural sweetness of the voices returns, only to slowly degrade with continuing playing of the track.
Hard wiring, bypassing the switch contacts is a permanent solution, from previous experience; but I lose the protection mechanism, plus have possible power on thumps through the speakers. Anyway, I will use this method for now to confirm that what I'm hearing is directly caused by the particular contacts - and then decide what to do about it, long term ...
Saturday 5 December 2015
To conjure, first learn to be a detective ...
I have an audio friend down the road who isn't afraid to try the weird and wonderful to get answers, and possible solutions - and I've been visiting over many years now. He had a new toy he wanted me to appraise, so last night I toddled over for a listen ... for many years he has been using competent, pocket media players as his digital source, and he had just acquired a well recommended, lowish cost unit which he was pleased with. And I had been impressed with the previous units he had used - usually significantly better than the tweaked CD player that had served him for many years.
First impressions ... hmmm, okay, but there was something amiss - he is usually capable of getting very satisfying sound, sometimes after some judicious fiddling on the fly ... but it wasn't happening at the moment. There was a flatness, a lack of sparkle - the sound wasn't as good as as I had heard many times previously, with other configurations he had optimised.
Long story short, after many, many experiments, including swapping amplifiers, there was no major movement forward ... the dullness, lack of 'musicality' wasn't going away. Then, there was a period of inspired combining of our thinking, and intuition, which caused us to focus on the improvised damping of the top cover of the amplifier ... over time, it had been worked out that the typical, thin metal top plate had an audible impact, and adding some damping and weighting materials helped. But now, in a seemingly crazy way, removing that and just using some scraps of fluffy viscoelastic material on top was giving us the best sound! What's going on, ... ??!!
Then, the "Ah-hah!!" moment occurred: he had replaced the smoothing capacitors in the amplifiers - the manufacturer's parts were under-rated for the job, and failed early in the amplifier's life; my friend's replacements were better suited, but were significantly taller; he couldn't get higher voltage rated units that better matched the original profile. And now some experiments confirmed that adding the mild damping precisely over where those capacitors were situated under the cover plate was the key!
It appears that the top of those capacitors were now too close to the sheet metal of the covers, and there was a sound modulating interaction between those two parts. Okay, rip off the cover, and insert two circles of damping material between the caps and plate - so when the latter was screwed back on the material was under compression, slight but unnoticeable bulge to the cover now ...
And, the good sound was back, with a vengence! Full, sweet, satisfying music on every track - the system was now well and truly in the "zone" ...
An excellent example of how important it is, firstly, to acknowledge that an audio system is not up to scratch; and secondly, to start investigating all the possible causes, reasonable and unreasonable, to try and track down where the flaws in the reproduction are originating - dedication to this approach is so important to being able to conjure up convincing sound.
Addendum: for anyone who wonders why the amplifier swap didn't impact the sound quality issue- the two units were in fact from the same manufacturer, Naim: Nait models which were different versions, but had the same casing and essential circuitry within; the power supply capacitors in both had been replaced by my friend, so the same problem manifested in both units.
First impressions ... hmmm, okay, but there was something amiss - he is usually capable of getting very satisfying sound, sometimes after some judicious fiddling on the fly ... but it wasn't happening at the moment. There was a flatness, a lack of sparkle - the sound wasn't as good as as I had heard many times previously, with other configurations he had optimised.
Long story short, after many, many experiments, including swapping amplifiers, there was no major movement forward ... the dullness, lack of 'musicality' wasn't going away. Then, there was a period of inspired combining of our thinking, and intuition, which caused us to focus on the improvised damping of the top cover of the amplifier ... over time, it had been worked out that the typical, thin metal top plate had an audible impact, and adding some damping and weighting materials helped. But now, in a seemingly crazy way, removing that and just using some scraps of fluffy viscoelastic material on top was giving us the best sound! What's going on, ... ??!!
Then, the "Ah-hah!!" moment occurred: he had replaced the smoothing capacitors in the amplifiers - the manufacturer's parts were under-rated for the job, and failed early in the amplifier's life; my friend's replacements were better suited, but were significantly taller; he couldn't get higher voltage rated units that better matched the original profile. And now some experiments confirmed that adding the mild damping precisely over where those capacitors were situated under the cover plate was the key!
It appears that the top of those capacitors were now too close to the sheet metal of the covers, and there was a sound modulating interaction between those two parts. Okay, rip off the cover, and insert two circles of damping material between the caps and plate - so when the latter was screwed back on the material was under compression, slight but unnoticeable bulge to the cover now ...
And, the good sound was back, with a vengence! Full, sweet, satisfying music on every track - the system was now well and truly in the "zone" ...
An excellent example of how important it is, firstly, to acknowledge that an audio system is not up to scratch; and secondly, to start investigating all the possible causes, reasonable and unreasonable, to try and track down where the flaws in the reproduction are originating - dedication to this approach is so important to being able to conjure up convincing sound.
Addendum: for anyone who wonders why the amplifier swap didn't impact the sound quality issue- the two units were in fact from the same manufacturer, Naim: Nait models which were different versions, but had the same casing and essential circuitry within; the power supply capacitors in both had been replaced by my friend, so the same problem manifested in both units.
Saturday 28 November 2015
A More Ambitious Upgrade - Part 10
Hooray! I recorded a couple of instances of the NAD system playing, in a pretty bad position: single mic, about 3 metres behind the right hand speaker, no attempts to optimise the recording quality at all, just to see how the sound came across ... a bit of The Faces and some old Blues from an el cheapo CD. Not bad methinks, gives a pretty good idea of what it sounds like ... so, as a pure, first experiment uploaded The Faces take on YouTube ...
Now, believe it or not, this is my very first attempt to put anything on YouTube,and I didn't get the settings right - only relatively low quality settings come up on playing ... so, plenty to do to get a far better experience for a viewer. But, I feel the essence of the replay largely working right comes through even in this first miserable go - check it out ... https://youtu.be/-R_mju7q7Z8 .
Have uploaded a new version, with multiple resolutions, and a couple of things fixed, The Art of Audio Conjuring - Take 4 ... https://youtu.be/acfeJyUFnLM
Starts part way through "Too Bad" of the CD, and then the complete "That's All You Need" with me announcing at beginning of the latter - head about 1 metre away from mic.
And a bit later ... uploaded the Blues combo, The Art of Audio Conjuring - Take 3, https://youtu.be/oWkBJ1v1XTM ... this starts during "Crying", Jimmy Witherspoon, followed by "Everybody Rock", Jimmy McCracklin - this is in HD, which may or may not help the replay quality ...
Now, believe it or not, this is my very first attempt to put anything on YouTube,
Have uploaded a new version, with multiple resolutions, and a couple of things fixed, The Art of Audio Conjuring - Take 4 ... https://youtu.be/acfeJyUFnLM
Starts part way through "Too Bad" of the CD, and then the complete "That's All You Need" with me announcing at beginning of the latter - head about 1 metre away from mic.
And a bit later ... uploaded the Blues combo, The Art of Audio Conjuring - Take 3, https://youtu.be/oWkBJ1v1XTM ... this starts during "Crying", Jimmy Witherspoon, followed by "Everybody Rock", Jimmy McCracklin - this is in HD, which may or may not help the replay quality ...
Wednesday 25 November 2015
A More Ambitious Upgrade - Part 9
All quiet on the western front ... okay, a decent delay without much being done here - life gets in the way at times, and my fiddling on the NADs has taken a back step while other things were handled ...
What is very clear is that filtering of mains interference is crucial in this system - my simple experiments minimising these particular factors has lifted the standard to very close to "conjuring" quality; the latest touch is allowing very nice, tonally sweet recovery of ambience and depth in very old, shellac derived recordings. The potential of this combo of audio gear has shown itself to be such that engineering some proper, long term usable filtering circuitry on the mains side will be worthwhile ... so, I'm currently investigating some of my older tweaking projects, and any good info on the net, gathering all that's necessary in ideas for making a cost effective solution happen.
The system is now good enough to do some recordings, with the new mic, to demonstrate progress made - I'll post these on YouTube for easy perusal - and also upload full quality versions on say, Dropbox.
One thing "new", for my own understanding of the relationship of the factors in making a combination have sufficient quality, from the experiments so far - a system which has had a good amount of intelligent thought put into the topology of the key circuitry, like the NAD units, will present recordings far better on cold start up than 'cheap' components - immediately after pressing Play on a morning switch on, we have a very likeable sound that projects quite a 'big' sense of the musical event; there is very little obvious unpleasantness, or lack of 'musicality', in well made recordings. Very low cost units, like TVs and PC monitors definitely aren't capable of this, they need extended warm up to reach an adequate stability of all the parts.
A reference recording I use for evaluating competence is Franck/Faure, The Medici String Quartet - Nimbus NI 5114 - Ambisonic recording, the piano sounds like it's half a mile away, very low levels of the primary sounds of the string instruments with relatively high levels of reverberation information. This is a nightmare for a conventional digital playback system, will typically be very dreary and flat in the listening, "boring" sound of the worst order. Only a fully sorted out system will resolve the fine detail, and reveal the musical structures correctly - and this is clearly showing the weaknesses of the NAD combo at this point: the acoustic of the recording is complex but subtle, and that fine detail is too entangled with the remaining low level distortion - the playback of this recording is not "working" yet.
What is very clear is that filtering of mains interference is crucial in this system - my simple experiments minimising these particular factors has lifted the standard to very close to "conjuring" quality; the latest touch is allowing very nice, tonally sweet recovery of ambience and depth in very old, shellac derived recordings. The potential of this combo of audio gear has shown itself to be such that engineering some proper, long term usable filtering circuitry on the mains side will be worthwhile ... so, I'm currently investigating some of my older tweaking projects, and any good info on the net, gathering all that's necessary in ideas for making a cost effective solution happen.
The system is now good enough to do some recordings, with the new mic, to demonstrate progress made - I'll post these on YouTube for easy perusal - and also upload full quality versions on say, Dropbox.
One thing "new", for my own understanding of the relationship of the factors in making a combination have sufficient quality, from the experiments so far - a system which has had a good amount of intelligent thought put into the topology of the key circuitry, like the NAD units, will present recordings far better on cold start up than 'cheap' components - immediately after pressing Play on a morning switch on, we have a very likeable sound that projects quite a 'big' sense of the musical event; there is very little obvious unpleasantness, or lack of 'musicality', in well made recordings. Very low cost units, like TVs and PC monitors definitely aren't capable of this, they need extended warm up to reach an adequate stability of all the parts.
A reference recording I use for evaluating competence is Franck/Faure, The Medici String Quartet - Nimbus NI 5114 - Ambisonic recording, the piano sounds like it's half a mile away, very low levels of the primary sounds of the string instruments with relatively high levels of reverberation information. This is a nightmare for a conventional digital playback system, will typically be very dreary and flat in the listening, "boring" sound of the worst order. Only a fully sorted out system will resolve the fine detail, and reveal the musical structures correctly - and this is clearly showing the weaknesses of the NAD combo at this point: the acoustic of the recording is complex but subtle, and that fine detail is too entangled with the remaining low level distortion - the playback of this recording is not "working" yet.
Friday 20 November 2015
Why does conventionally set up audio normally fail to 'conjure'?
There are many factors at work, but the fundamental reason is that insufficient experimenting and research has gone into understanding how people can pick up on subtle clues in what they're hearing, usually unconscious, which allows them to easily separate 'real' sounds from an attempted mimicking of such via a high fidelity system. Most playback manifests clearly audible "flaws", which then makes it trivially easy for the mind to "spot the fake", and once this happens the mind will automatically keep referencing these "defects", reinforcing one's awareness that the illusion has failed. An analogy would be watching a stage magician after being made aware somehow of how he does it - the tricks will be quite obvious, and part of one will be somewhat surprised that others in the audience don't also see how the manipulation occurs - your attention has been drawn, irreversibly, to the "chinks in the armour" of the stage act, and while you may be impressed by the magician's skill you no longer marvel at the "trick" itself.
It is unfortunate that during the history of audio reproduction that more in depth examination of the crucial factors didn't happen - many of the pioneers had an intuitive understanding of what was necessary, but this didn't evolve into an industry wide set of highly effective standards and rules which everyone could usefully reference; Paul Klipsch is a good example of such a person.
So, the illusion usually fails ... again, why? The answer, because the distortion, meaning elements of the audible sound which don't match the recording content, is too obvious, and intrusive. Most of the industry with a technical focus has become infatuated with easily obtainable raw numbers on behaviours of the individual components of a system: the source mechanism, the amplifier, the speakers exist in completely different spaces, are seen as separate units on a test bench; the overall performance of a complete system in its final environment is seen as something that is too hard to measure - that aspect which is in fact the most important of all is never sensibly dealt with. Unfortunately, the types of distortion which will always cause the illusion to collapse or fail to manifest easily arise in an end system, many times as a result of interaction between the components and the environment in which it finds itself. The fact that the "measurers" are remarkably blind to this is a bind that the audio industry is currently trapped in, and there are no signs as yet of any meaningful progress ...
But fortunately this does not stop the individual being able to bypass these limitation of thinking, and now and again one can read how this has been done by someone who has chanced upon a lucky combination of factors that reduce the key distortion sufficiently.
It is unfortunate that during the history of audio reproduction that more in depth examination of the crucial factors didn't happen - many of the pioneers had an intuitive understanding of what was necessary, but this didn't evolve into an industry wide set of highly effective standards and rules which everyone could usefully reference; Paul Klipsch is a good example of such a person.
So, the illusion usually fails ... again, why? The answer, because the distortion, meaning elements of the audible sound which don't match the recording content, is too obvious, and intrusive. Most of the industry with a technical focus has become infatuated with easily obtainable raw numbers on behaviours of the individual components of a system: the source mechanism, the amplifier, the speakers exist in completely different spaces, are seen as separate units on a test bench; the overall performance of a complete system in its final environment is seen as something that is too hard to measure - that aspect which is in fact the most important of all is never sensibly dealt with. Unfortunately, the types of distortion which will always cause the illusion to collapse or fail to manifest easily arise in an end system, many times as a result of interaction between the components and the environment in which it finds itself. The fact that the "measurers" are remarkably blind to this is a bind that the audio industry is currently trapped in, and there are no signs as yet of any meaningful progress ...
But fortunately this does not stop the individual being able to bypass these limitation of thinking, and now and again one can read how this has been done by someone who has chanced upon a lucky combination of factors that reduce the key distortion sufficiently.
Thursday 12 November 2015
A More Ambitious Upgrade - Part 8
Another nice little step forward ... I was noting that a very low key ambient music CD, designed for meditation background filler, which has very long, richly harmonic notes had a decided rattly tone coming in - this sounded like speaker misbehaviour. I had sorted out the obvious weaknesses of the internals of these cheap speakers some time ago, was there something more to be done ...? Turned out that an elastic material that I had applied some time ago to decouple the tweeter from its support had gone rock solid in the interim, it just crumbled away in slivers when a knife was applied! OK, this was a definite issue!
As a simple experiment - the type I prefer! - I applied good ol' Blu-Tack to the support areas in such a fashion that this goo was the sole method holding the treble driver in place; the screws were left off entirely. Definitely not a production line process, but good enough to give me answers - and so far a positive outcome. An improvement in clarity, dynamics ... another step closer to convincing sound ...
Update: an interesting aspect of higher quality sound is that one's brain can assimilate and process all the information coming from the playback source, and separate that from all peripheral and echo sound data with ease. I say this because the NAD system while I've been working on it is positioned 1/3rds length ways into the work room, facing the closer wall to it; when I sit at my laptop and do whatever, like updating this post, the speakers are facing completely away from me, so the sound for me is that bouncing from the walls and glass, mostly indirect input to my ears. Yet the sound totally "works", is completely authentic in character, requires no excuses for the fact that my hearing position is as bad as I could make it ...
As a simple experiment - the type I prefer! - I applied good ol' Blu-Tack to the support areas in such a fashion that this goo was the sole method holding the treble driver in place; the screws were left off entirely. Definitely not a production line process, but good enough to give me answers - and so far a positive outcome. An improvement in clarity, dynamics ... another step closer to convincing sound ...
Update: an interesting aspect of higher quality sound is that one's brain can assimilate and process all the information coming from the playback source, and separate that from all peripheral and echo sound data with ease. I say this because the NAD system while I've been working on it is positioned 1/3rds length ways into the work room, facing the closer wall to it; when I sit at my laptop and do whatever, like updating this post, the speakers are facing completely away from me, so the sound for me is that bouncing from the walls and glass, mostly indirect input to my ears. Yet the sound totally "works", is completely authentic in character, requires no excuses for the fact that my hearing position is as bad as I could make it ...
Sunday 8 November 2015
A More Ambitious Upgrade - Part 7
Good progress made! I bit the bullet and added an effectively almost 100% bypass of the volume potentiometer, to make clear how much was being lost here; at maximum volume setting the level is set by a pair of series metal film resistors acting as voltage divider, the mechanism of the pot is almost completely invisible to the rest of the circuit. This I made a sensible, comfortable listening level well below the capability of the amplifier - and, I still retain the ability to attenuate the volume by adjusting the potentiometer back from fully clockwise.
This immediately showed a major benefit, the irritating buildup of low level distortion was now gone - a CD of 60's Jan and Dean surf music recorded by Brian Wilson showed tremendous depth, complexity and sparkle on tracks, quite spectacular to listen to!
The listening just a short time ago demonstrated a behaviour that happens over and over again when deliberately targeted tweaking to remove weaknesses is done: even though the sound had lost the unpleasant edge caused by the potentiometer part there was now a sense of loss of information in some disks, the sound wasn't as "big" as it should have been. Some experiments and thinking of what had been tried so far gave me the Ah-haaa! answer: so far I've been using rough, simple experimental manipulation of the power supply quality outside the component boxes to clean up interference; and I had doubled up the filtering on the amplifier side - this was in fact a mistake, the filters in action weren't combining in positive ways at all times. The cleaning up of the sound to a better level by improving the volume mechanism now made this much clearer; before, the masking by the dirt added from the potentiometer hid this effect.
So ... at all times be ready to step back and reassess where the sound is at, and be willing to undo an earlier change even though it made sense at the time, and appeared to be a positive. The flaws in a system causing the end sound to not be as good as it could be are a complex interaction of factors - the best, final results will always flow from a willingness to completely change one's approach in some area, on the basis of new evidence from ongoing, careful evaluation of the sound one is hearing.
Where's the sound at now? Very spacious, full - the ambience of the recording environment is getting mighty close to taking over the listening room - not quite at "invisible" speakers, it is still possible to pinpoint their location - but, there remains tonnes of things to be looked at, many aspects I normally do consider have yet to be addressed ... I'm sure I'll get there!
But ... what about, you know, 'conjuring'? Is it there yet? No. I'm getting more detail, a bigger sound ... but that is also making it easier to pick up where the remaining failings are ... possibly quite a few more rounds to go, c'est la vie ...
This immediately showed a major benefit, the irritating buildup of low level distortion was now gone - a CD of 60's Jan and Dean surf music recorded by Brian Wilson showed tremendous depth, complexity and sparkle on tracks, quite spectacular to listen to!
The listening just a short time ago demonstrated a behaviour that happens over and over again when deliberately targeted tweaking to remove weaknesses is done: even though the sound had lost the unpleasant edge caused by the potentiometer part there was now a sense of loss of information in some disks, the sound wasn't as "big" as it should have been. Some experiments and thinking of what had been tried so far gave me the Ah-haaa! answer: so far I've been using rough, simple experimental manipulation of the power supply quality outside the component boxes to clean up interference; and I had doubled up the filtering on the amplifier side - this was in fact a mistake, the filters in action weren't combining in positive ways at all times. The cleaning up of the sound to a better level by improving the volume mechanism now made this much clearer; before, the masking by the dirt added from the potentiometer hid this effect.
So ... at all times be ready to step back and reassess where the sound is at, and be willing to undo an earlier change even though it made sense at the time, and appeared to be a positive. The flaws in a system causing the end sound to not be as good as it could be are a complex interaction of factors - the best, final results will always flow from a willingness to completely change one's approach in some area, on the basis of new evidence from ongoing, careful evaluation of the sound one is hearing.
Where's the sound at now? Very spacious, full - the ambience of the recording environment is getting mighty close to taking over the listening room - not quite at "invisible" speakers, it is still possible to pinpoint their location - but, there remains tonnes of things to be looked at, many aspects I normally do consider have yet to be addressed ... I'm sure I'll get there!
But ... what about, you know, 'conjuring'? Is it there yet? No. I'm getting more detail, a bigger sound ... but that is also making it easier to pick up where the remaining failings are ... possibly quite a few more rounds to go, c'est la vie ...
Saturday 7 November 2015
A More Ambitious Upgrade - Part 6
The volume control will have to be sorted! I've been dallying around, noting other factors that impact the quality, but I keep coming back to that part. Especially this morning, it's clearly crippling the replay of a nice, sparse orchestral, recent recording - Bev is picking the impact from the other end of the noise, the low level ambience and sparkle is compromised, there's a deadness, loss of verve to the sound which makes the listening a bit of a chore. This can be momentarily fixed by refreshing the pot's setting but that only lasts for a very short time; up close to the tweeter this short term "fixing" can easily be heard in action - before adjusting the volume there is distinct distortion from the tweeter - classic "hashy" unpleasantness, after cleaning the pot, that degradation completely disappears.
So how to do it? As mentioned before, I don't want to spend silly effort and money - will getting a significantly better variable resistance mechanism make the issue go away as an audible problem under normal listening? This is the first time I've really grappled with an analogue volume control problem, so I'll do some more research and then get hold of the best value, easily available replacement, and see what that gives me ....
On a strongly positive note, I have acquired a decent USB condenser microphone, and the first test is showing a very good result - I aim to make recordings of what comes out of the speakers, such that it clearly shows the points I'm making, and post them them so that they're easily accessed, say YouTube for quick perusal, and Dropbox for better quality versions.
So how to do it? As mentioned before, I don't want to spend silly effort and money - will getting a significantly better variable resistance mechanism make the issue go away as an audible problem under normal listening? This is the first time I've really grappled with an analogue volume control problem, so I'll do some more research and then get hold of the best value, easily available replacement, and see what that gives me ....
On a strongly positive note, I have acquired a decent USB condenser microphone, and the first test is showing a very good result - I aim to make recordings of what comes out of the speakers, such that it clearly shows the points I'm making, and post them them so that they're easily accessed, say YouTube for quick perusal, and Dropbox for better quality versions.
Thursday 29 October 2015
A More Ambitious Upgrade - Part 5
Progress has been made, in improving the quality of the volume control, but there is still clearly audible degradation. As a first major reworking I altered the circuitry around the potentiometer to turn it into a shunt topology, with immediate, obvious, audible benefit - the series resistor in the top arm leg was a fairly large value with the intended result that much more of the pot travel would be used in normal listening. Very much a step upward in the sound, and at first I was very pleased, thinking that maybe enough had been done to offset the inherent flaws in the construction of the potentiometer part; but, being the sort of person I am I immediately started using more testing recordings to highlight details of behaviour, and - you know what's coming - finally tried a track where the losses were very clear: a 'dirty' quality could be heard, which temporarily went away when the volume setting was jiggled, cleaning the contact points momentarily.
So, more has to be done! I'm not keen on simply buying, installing a much more expensive, 'higher quality' pot - I suspect that I won't make the problem go away, based on previous experience, merely slightly lessen the audible degradation - what I want is a complete solution. Without spending silly money, or going through strenuous contortions to get a better mechanism in place ...
That said, the system is in a pretty good space - most recordings come across very well, much better than the typical standard of 'audiophile' rigs: solo piano, harpsichord, is intense, rich and vibrant; massed string section playing has that sweet, satisfying sheen to it ... but, "poorly recorded" tracks catch it out still.
So, more has to be done! I'm not keen on simply buying, installing a much more expensive, 'higher quality' pot - I suspect that I won't make the problem go away, based on previous experience, merely slightly lessen the audible degradation - what I want is a complete solution. Without spending silly money, or going through strenuous contortions to get a better mechanism in place ...
That said, the system is in a pretty good space - most recordings come across very well, much better than the typical standard of 'audiophile' rigs: solo piano, harpsichord, is intense, rich and vibrant; massed string section playing has that sweet, satisfying sheen to it ... but, "poorly recorded" tracks catch it out still.
Friday 23 October 2015
A More Ambitious Upgrade - Part 4
The usual process is taking place, that is, as movement forward is made, the remaining inadequacies that were not readily noticeable earlier become more prominent, become easier to discern and easier to tie directly to some part of the whole. In my previous update I said I felt I was in good shape, but underlying that was the concern that the volume control, a cheap Alps potentiometer implemented in a very conventional way, would start to rear its ugly head - volume controls are a huge concern in audio, and my previous experiences are that all straight analogue methods are too great a degrading factor; hence, and luckily by accident, I have always used digital control or semiconductor circuitry to date - no raw switches or wiper on tracks used. With good results ...
Which brings me with dealing with the NAD amp. Its virtues have shone brightly enough so far, but a day or so ago an album which quite quickly developed a dirty, irksome edge to the sound got my attention. Was this the volume pot becoming too much a problem, finally? Yes, it was - a quick jiggle of the volume setting cleaned up the sound momentarily and then the unsavoury quality to the tone started to fairly quickly build up again. Bummer !!! Now that I can "hear it" I'll always be aware of its effect, unfortunately.
So, I'll have to bite the bullet! I've never done a major exercise of resolving potentiometer quality issues up to now, I've always been able to sidestep them - but this time my focus is different: I really want to get the best out of the gear without major re-engineering of parts of the components - a "simple" solution is to rip out the pot and install a full-blown, very high quality semiconductor or possibly discrete relays and resistors circuit. But this is an involved, relatively expensive approach - I won't go there until all low cost alternatives are explored.
This means that I'm now in full flight in investigating what the experiences of others are, what tweaks and tricks have been used - and will start trying the best ideas that I come across ...
Which brings me with dealing with the NAD amp. Its virtues have shone brightly enough so far, but a day or so ago an album which quite quickly developed a dirty, irksome edge to the sound got my attention. Was this the volume pot becoming too much a problem, finally? Yes, it was - a quick jiggle of the volume setting cleaned up the sound momentarily and then the unsavoury quality to the tone started to fairly quickly build up again. Bummer !!! Now that I can "hear it" I'll always be aware of its effect, unfortunately.
So, I'll have to bite the bullet! I've never done a major exercise of resolving potentiometer quality issues up to now, I've always been able to sidestep them - but this time my focus is different: I really want to get the best out of the gear without major re-engineering of parts of the components - a "simple" solution is to rip out the pot and install a full-blown, very high quality semiconductor or possibly discrete relays and resistors circuit. But this is an involved, relatively expensive approach - I won't go there until all low cost alternatives are explored.
This means that I'm now in full flight in investigating what the experiences of others are, what tweaks and tricks have been used - and will start trying the best ideas that I come across ...
Friday 16 October 2015
What do I mean, Audio Conjuring ??
Simply put, the intention is to create an illusion that one is hearing the "real thing" when listening to replay of musical recordings - which then brings in one's interpretation of the word "real", in this context. Most would have an intuitive understanding of what I'm getting at, a simple example is a CD recording of some classical, solo piano music: if this is always able to "fool" you and anyone else into thinking that there is a real grand piano, and real, highly competent pianist in your home, say, both on a casual coming across the sound of it happening, and also when closely, carefully listening to the quality of the tone and other elements of how the sound comes across.
This just then naturally extends to any and all recordings being played on the audio system: they never draw attention to the fact that they are a 'fake', they are convincing in their presentation. One should never be aware that you are listening to an electronic, mechanical contrivance doing the work of generating the sound in the space - if this happens, then the conjuring "trick" has failed.
It's as simple as that ...
This just then naturally extends to any and all recordings being played on the audio system: they never draw attention to the fact that they are a 'fake', they are convincing in their presentation. One should never be aware that you are listening to an electronic, mechanical contrivance doing the work of generating the sound in the space - if this happens, then the conjuring "trick" has failed.
It's as simple as that ...
Thursday 15 October 2015
A More Ambitious Upgrade - Part 3
Appears that I've cleared the first major hurdle in this process - the system now has 'mojo', the ability to draw one into the sound; it just "works" as a way of experiencing a 'historical' musical event - I don't have to make mental excuses for it "not being quite right" ...
This came about through eliminating the Balance pot, potentiometer - I knew it was causing some degradation, because moving its position when the sound was irky, and thus momentarily cleaning the contacts, decidedly improved things. So, this part was effectively chopped out of the circuit and fixed resistors which mimicked a centre setting for the control were inserted. But I was still surprised by the degree of improvement - I note that the service manual "proudly" states that these parts are by Alps ... this didn't help much ... :-)
Even CD-R disks which are straining the error correction circuitry, as evidenced by the popping and snapping sounds, and much skipping, are quite possible to listen to .... for a while.
So, I'm a happy chappy - there is still much that can and needs to be done, but the quality is already at a very good standard - plenty of potential to exploit.
This came about through eliminating the Balance pot, potentiometer - I knew it was causing some degradation, because moving its position when the sound was irky, and thus momentarily cleaning the contacts, decidedly improved things. So, this part was effectively chopped out of the circuit and fixed resistors which mimicked a centre setting for the control were inserted. But I was still surprised by the degree of improvement - I note that the service manual "proudly" states that these parts are by Alps ... this didn't help much ... :-)
Even CD-R disks which are straining the error correction circuitry, as evidenced by the popping and snapping sounds, and much skipping, are quite possible to listen to .... for a while.
So, I'm a happy chappy - there is still much that can and needs to be done, but the quality is already at a very good standard - plenty of potential to exploit.
A More Ambitious Upgrade - Part 2
Some major movement forward, up to now I've
given the gear the benefit of the doubt, and just hooked it up to the
mains in a very conventional way - but the tonality issues were now
getting too strident ... the prime culprit turns out to be the CDP, by
virtue of the highly inadequate isolating of mains noise junk from
causing cross-interference - extremely typical of usual audio. I use
very simple, zero cost or close to it techniques for troubleshooting -
the simple exercise of setting up a dedicated mains spur for the CDP
alone with some token mains filtering pinpointed the cause of this
quality aspect. This now gives me very good solo piano tone, capable of
being run at realistic levels, which sounds pretty good directly in
front of the speakers as well as the other end of the house, and outside
- vastly better to listen to than the typical ambitious, expensive
audiophile rig, :-P .
But interestingly, I seem to have a bit of a noise issue - never experienced this before as being so noticeable. This is classic, resistor thermal noise hiss - not the recording, a digital album still shows the problem. I wonder if this is because all of the NAD circuitry is discrete - yet more investigation needed !
But interestingly, I seem to have a bit of a noise issue - never experienced this before as being so noticeable. This is classic, resistor thermal noise hiss - not the recording, a digital album still shows the problem. I wonder if this is because all of the NAD circuitry is discrete - yet more investigation needed !
A More Ambitious Upgrade - Part 1
I've been motivated to fix up and optimise another cheap
system: some discarded NAD units, almost 20 year old CD player and amplifier driving good, "boombox" speakers. Very promising early signs, tonnes
of genuine dynamics in the raw state; has the usual flaws of developing
a very 'dirty', unpleasant edge with steady playing - quite a bit of
cleaning up and tidying to be done, but excellent potential ...
There's a NAD C 540 CDP (CD only player), 304 integrated amplifier, and Sharp boombox speakers - from a classic, modern 3 identically sized boxes with all the electronics in the middle system; the speakers have a solid bass/mid unit, rated to take 200W, so no prob's there.
As usual, all the issues are with the electronics: to start with, the full setup had a cheap but cheerful sound, at least for a while from startup, until the electronics got really a dirty tone with ongoing use. As expected, the internals are riddled with weaknesses, poor implementation details, which all have to be sorted - the unfortunate thing is that mildly ambitious units like the NAD get lots of things right, but all the leftovers then combine to drag down the potential dramatically, they often sound considerably worse than a very simple, totally unambitious sound unit, in the sense of being less "musical".
Which is a way of saying that I'm in that awkward middle stage of tweaking, where quite a number of flaws have been bypassed, lifting the standard in some aspects, but putting the remaining ones in much sharper focus - the whole now very easily produces downright unpleasant sound, :-P . Many people could give up now, saying they preferred the easier to listen to, somewhat gunked up sound of the raw units - but that would be a failure of effort, big time !!
The CDP has a pretty hopeless reader mechanism engineered, CD-Rs are a huge obstacle, sound much worse than an LP with continual crackling and popping as the error correction struggles, all my other rubbishy computer and audio CD drives handle these disks with zero audible problems. But, NAD is known for this, ;-) - will explore some avenues here.
My other recent fiddling with cheap stuff was much easier, because so many flaws were eliminated by virtue of close integration of the electronic elements - the designers got that part right! The NADs, like nearly all of this type of electronics, have flaky elements everywhere - and each and every one has to be tracked down to get the best out of the whole.
A couple of thoughts on current progress: can do big orchestral climaxes with greater SPL than my other recent efforts, but tonality still has some way to go; massed strings, piano and such are often not right, sweetness goes off far too quickly ...
There's a NAD C 540 CDP (CD only player), 304 integrated amplifier, and Sharp boombox speakers - from a classic, modern 3 identically sized boxes with all the electronics in the middle system; the speakers have a solid bass/mid unit, rated to take 200W, so no prob's there.
As usual, all the issues are with the electronics: to start with, the full setup had a cheap but cheerful sound, at least for a while from startup, until the electronics got really a dirty tone with ongoing use. As expected, the internals are riddled with weaknesses, poor implementation details, which all have to be sorted - the unfortunate thing is that mildly ambitious units like the NAD get lots of things right, but all the leftovers then combine to drag down the potential dramatically, they often sound considerably worse than a very simple, totally unambitious sound unit, in the sense of being less "musical".
Which is a way of saying that I'm in that awkward middle stage of tweaking, where quite a number of flaws have been bypassed, lifting the standard in some aspects, but putting the remaining ones in much sharper focus - the whole now very easily produces downright unpleasant sound, :-P . Many people could give up now, saying they preferred the easier to listen to, somewhat gunked up sound of the raw units - but that would be a failure of effort, big time !!
The CDP has a pretty hopeless reader mechanism engineered, CD-Rs are a huge obstacle, sound much worse than an LP with continual crackling and popping as the error correction struggles, all my other rubbishy computer and audio CD drives handle these disks with zero audible problems. But, NAD is known for this, ;-) - will explore some avenues here.
My other recent fiddling with cheap stuff was much easier, because so many flaws were eliminated by virtue of close integration of the electronic elements - the designers got that part right! The NADs, like nearly all of this type of electronics, have flaky elements everywhere - and each and every one has to be tracked down to get the best out of the whole.
A couple of thoughts on current progress: can do big orchestral climaxes with greater SPL than my other recent efforts, but tonality still has some way to go; massed strings, piano and such are often not right, sweetness goes off far too quickly ...
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