A short update, not much has happened, but a couple of items to be noted ...
A nuisance, hopefully doesn't deteriorate more, but the NAD CD player now often is down the right channel at switch on from cold - takes some minutes of playing before it suddenly comes on line, or starts crackling and buzzing before steadily working itself fully back to stable sound. To me, this is an active component part playing up, not liking to get out of bed in the morning - once in its stride, no audible artifacts from then on in the listening, etc.
No matter how much one is aware of the fact that little things that matter, it is still easy to make mistakes! I normally carefully route all cabling, everywhere, for minimum possible interference effects to occur. But ... the speakers are mounted on flat, large slabs of MDF, to somewhat stabilise them in their very temporary location while the system is being fiddled with ... and, I had cabling, etc sitting across these boards. To cut to the chase, the vibration the speakers were transmitting to these boards was causing too much movement in the materials of these bits and pieces - the sound was being negatively affected! Tidy this up - problem solved ...
I have computer networking in the same room, no wireless, just ethernet - and it connected up and functional still causes audible interference ... I need to make the isolation and shielding yet more robust. Unfortunately, complete isolating this or any other audio system electrically from any external noise making gear is a real headache, there are no easy answers that I have found - one needs to keep plugging away until all the "gaps" are closed, for optimum sound.
Showing posts with label A More Ambitious Upgrade. Show all posts
Showing posts with label A More Ambitious Upgrade. Show all posts
Wednesday, 3 February 2016
Friday, 22 January 2016
A More Ambitious Upgrade - Part 17
Unfortunately, not much more to report - too many tussles with other parts of the household in the interim, having things go wrong seems to go in cycles! The only real progress with the audio is that I have started experimenting with adding some interference reduction measures, which appear to be helping matters - the CD player, as I would have expected, seems to be the more susceptible - meaning, it needs an extremely clean electrical environment for there not to be obvious degradation. Wireless phones, as in mobiles and home units, are as bad offenders as they have been in the past, and I have yet to find a definitive solution for this in general - perhaps only a 100% thoroughly re-engineered system will be completely immune from audible effects ...
The system currently hovers between conjuring and non-conjuring - if all the stops are pulled out then the quality constantly delights, I can put on a CD I haven't heard in years and it's a real pleasure, the texture of the sound draws me in and immediately there's a skip in my step. But, it only takes something like a mobile phone operating in the house to cripple that, the injection of the accompanying electrical disturbance is enough to contaminate the low level detail, and the speakers become very obvious, they don't "disappear".
Also, I really must get cracking and do some proper recordings of the system playback, and upload - at the moment I can get stuck too easily in Round Tuit territory ... more effort is needed!!
The system currently hovers between conjuring and non-conjuring - if all the stops are pulled out then the quality constantly delights, I can put on a CD I haven't heard in years and it's a real pleasure, the texture of the sound draws me in and immediately there's a skip in my step. But, it only takes something like a mobile phone operating in the house to cripple that, the injection of the accompanying electrical disturbance is enough to contaminate the low level detail, and the speakers become very obvious, they don't "disappear".
Also, I really must get cracking and do some proper recordings of the system playback, and upload - at the moment I can get stuck too easily in Round Tuit territory ... more effort is needed!!
Monday, 4 January 2016
A More Ambitious Upgrade - Part 16
Okay, time for a quick recap ...
I'm satisfied I've got the combination of NAD CD player and integrated amplifier, and simple Sharp shelf speakers over the first hurdle: if enough care is used to control the electrical environment around it then it conjures, very nicely. At the moment I'm playing a EMI 1964 opera CD, lovely full rich sound that expands as far anyone could want, with the speakers totally "invisible" - and the same goes for a real roughie, like the original Rolling Stones London album, played yesterday; the sound completely lifts out of the speakers.
But, I've got fixed volume, so to speak - I still haven't resolved the final solution for this, which will require trying at least one better quality potentiometer - on the To Do list. And, as I've experienced over and over again, external and possibly mutual electrical interference are problematic, the "good stuff" is only wrought when all sorts of "silly" fudges are organised for the electrical items in the house - this is a pain(!), and must be properly sorted by adding filtering and shielding as appropriate. Plus, the fixed volume I'm using is not pushing the amplifier into areas where it is substantially stressed - will the quality sustain for continuously elevated levels, like modern, heavily compressed pop?
What is very significant, is that from cold turn on the sound is highly competent, very little warm up time, if any, is necessary for satisfying replay to be had - and, almost no component substitution has been done so far: no electrolytic capacitors replaced, no swapping of other passive, and active parts done; not even the power supplies have been touched. So, there is plenty of manouvering room to enhance quality further - this is an excellent sign, the potential appears to be there for some impressive reproduction capability ...
I'm satisfied I've got the combination of NAD CD player and integrated amplifier, and simple Sharp shelf speakers over the first hurdle: if enough care is used to control the electrical environment around it then it conjures, very nicely. At the moment I'm playing a EMI 1964 opera CD, lovely full rich sound that expands as far anyone could want, with the speakers totally "invisible" - and the same goes for a real roughie, like the original Rolling Stones London album, played yesterday; the sound completely lifts out of the speakers.
But, I've got fixed volume, so to speak - I still haven't resolved the final solution for this, which will require trying at least one better quality potentiometer - on the To Do list. And, as I've experienced over and over again, external and possibly mutual electrical interference are problematic, the "good stuff" is only wrought when all sorts of "silly" fudges are organised for the electrical items in the house - this is a pain(!), and must be properly sorted by adding filtering and shielding as appropriate. Plus, the fixed volume I'm using is not pushing the amplifier into areas where it is substantially stressed - will the quality sustain for continuously elevated levels, like modern, heavily compressed pop?
What is very significant, is that from cold turn on the sound is highly competent, very little warm up time, if any, is necessary for satisfying replay to be had - and, almost no component substitution has been done so far: no electrolytic capacitors replaced, no swapping of other passive, and active parts done; not even the power supplies have been touched. So, there is plenty of manouvering room to enhance quality further - this is an excellent sign, the potential appears to be there for some impressive reproduction capability ...
Sunday, 3 January 2016
A More Ambitious Upgrade - Part 15
Regarding the robustness of the sound quality, and awkwardness at this point of tuning, as mentioned in the previous chapter - I have a real issue with a mobile phone at the moment: switched on, even at the other end of the house it is coupling in some manner to the system, most likely via the mains power cabling - and results in the sound deadening. A flatness, major drop off in sparkle occurs, the particular interference, distortion mechanism doesn't create noise in the usual sense, but turns the sound into a much duller, "smaller", 2D version of the event - one loses interest quickly, the "life" has been sucked out of the music ...
This has been the case with all my system experiments so far in our age of the wireless phone, and it is very difficult to cure - by far the easiest solution is to simply turn off, fully, all such phones; but in this day and age this is not really a reasonable approach. A fully comprehensive solution I have not yet devised ... something for the future to sort out ...
This has been the case with all my system experiments so far in our age of the wireless phone, and it is very difficult to cure - by far the easiest solution is to simply turn off, fully, all such phones; but in this day and age this is not really a reasonable approach. A fully comprehensive solution I have not yet devised ... something for the future to sort out ...
Sunday, 27 December 2015
A More Ambitious Upgrade - Part 14
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 ...
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 ...
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 ...
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 ...
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, 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.
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 ...
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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