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CD transports and resonance
Following on from previous posts where I found that various damping materials
affected the sound of my Pioneer CDP used as transport only (I have an outboard DAC), I've found the same with the CD-Rom I'm now using. I went over to the CD-Rom because the build was more sturdy and there seemed to be a better sound in it, which started to happen when I swapped the switch-mode power supply for a normal toroid PSU. That's the story so far Latest step was to bolt the CD-Rom down to a 10mm slab of aluminium 9.5" by 6.5". This after seeing the Flatfish which is exactly that. It's sitting on the carpet as I write - haven't tried any fancy feet yet! Well, the sound is very noticeably clearer. A CD-Rom vibrates quite a bit in your hand, so I guess this is dampening it usefully. The most noticeable thing is that louder passages are less congested and shouty - they have soothed out audibly. Now I have no idea why resonances affect CD transports, but this is without any doubt what I'm hearing - change the damping, change the sound. I suppose this is back to the debate whether 'bits are bits' or whether the signal is complex and affected by other factors. Since it isn't hard to try, maybe somebody else would like to replicate bolting a CD-rom down to a 10mm slab of alu? I wonder if the measurements would be different on any parameters. Andy === Andy Evans === Visit our Website:- http://www.artsandmedia.com Audio, music and health pages and interesting links. |
CD transports and resonance
Andy Evans wrote:
Following on from previous posts where I found that various damping materials affected the sound of my Pioneer CDP used as transport only (I have an outboard DAC), I've found the same with the CD-Rom I'm now using. I went over to the CD-Rom because the build was more sturdy and there seemed to be a better sound in it, which started to happen when I swapped the switch-mode power supply for a normal toroid PSU. That's the story so far Latest step was to bolt the CD-Rom down to a 10mm slab of aluminium 9.5" by 6.5". This after seeing the Flatfish which is exactly that. It's sitting on the carpet as I write - haven't tried any fancy feet yet! Well, the sound is very noticeably clearer. A CD-Rom vibrates quite a bit in your hand, so I guess this is dampening it usefully. The most noticeable thing is that louder passages are less congested and shouty - they have soothed out audibly. Now I have no idea why resonances affect CD transports, but this is without any doubt what I'm hearing - change the damping, change the sound. I suppose this is back to the debate whether 'bits are bits' or whether the signal is complex and affected by other factors. Since it isn't hard to try, maybe somebody else would like to replicate bolting a CD-rom down to a 10mm slab of alu? I wonder if the measurements would be different on any parameters. Andy No doubt these will be available soon from all good snake oil outlets. IAn -- Ian Bell |
CD transports and resonance
No doubt these will be available soon from all good snake oil outlets.
We're talking engineering here - Fays metals, Chiswick. The difference is quite audible, as I said, so I'm interested in knowing how resonance dampening affects CD transports. Andy. === Andy Evans === Visit our Website:- http://www.artsandmedia.com Audio, music and health pages and interesting links. |
CD transports and resonance
Andy Evans wrote:
Since it isn't hard to try, maybe somebody else would like to replicate bolting a CD-rom down to a 10mm slab of alu? I wonder if the measurements would be different on any parameters. Andy I'll try it if you can *measure* any difference in the output of your own setup. |
CD transports and resonance
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CD transports and resonance
Since it isn't hard to try, maybe somebody else would like to replicate
bolting a CD-rom down to a 10mm slab of alu? I wonder if the measurements would be different on any parameters. Andy I'll try it if you can *measure* any difference in the output of your own setup.(IanM) I don't have the gear or the knowledge when it comes to digital electronics - it's an area I know very little about. Andy === Andy Evans === Visit our Website:- http://www.artsandmedia.com Audio, music and health pages and interesting links. |
CD transports and resonance
On Fri, 05 Nov 2004 21:40:23 +0000, Andy Evans wrote:
Following on from previous posts where I found that various damping materials affected the sound of my Pioneer CDP used as transport only (I have an outboard DAC), I've found the same with the CD-Rom I'm now using. I went over to the CD-Rom because the build was more sturdy and there seemed to be a better sound in it, which started to happen when I swapped Surely, the whole point of a *digital* media like CD is that there can be *no* change at all to the sound, no matter what turns the disk or how it is supported. All you get back from the laser assembly is digital data. Now, after that you can change things. An outboard DAC with its own PSU is *probably* going to give better results than the built-in one running off the motor PSU - it depends on a lot of things. You really need to do *measurements* of both the raw data and the DAC output signal from the same drive mounted on the plate & off it before you can start along these lines. Yes, the error correction system will cause differences and you *may* reduce errors by bolting the transport down solidly. That won't necessarily make any audible or measurable difference at all to the output from the DAC though. You may reduce "skipping" on faulty disks too, as the drive mechanics may operate more precisely with a better support and, possibly, more inertia in the mounting. I read somewhere (sorry, can't give a ref) that the error correction on transports intended for audio is more lax than on those intended for data, as your ears are incapable of detecting low error rates but are more sensitive to the gaps caused by error correction. If that is so, then using a data drive for audio may give a different sound, but not one that is necessarily "better" as it will contain a different sort of inaccuracy! I'm sure someone will be able to correct me on this if I'm wrong. OTOH, if it sounds better to you, then do it! There is only you to be satisfied at the end of the day. They are *your* ears after all! Don't try to quantify the results as "better" to those of a more scientific bent though. They tend to like to see proof of "better"... ;-) -- Mick (no M$ software on here... :-) ) Web: http://www.nascom.info |
CD transports and resonance
"Andy Evans" wrote in message
Following on from previous posts where I found that various damping materials affected the sound of my Pioneer CDP used as transport only (I have an outboard DAC), Oh, your memos from placebo-land? I've found the same with the CD-Rom I'm now using. ....because your preconceived notions haven't changed. I went over to the CD-Rom because the build was more sturdy and there seemed to be a better sound in it, which started to happen when I swapped the switch-mode power supply for a normal toroid PSU. Constructor's ear. That's the story so far Latest step was to bolt the CD-Rom down to a 10mm slab of aluminium 9.5" by 6.5". You'd have a lot to think about if you did any reasonble testing, subjective or technical. This after seeing the Flatfish which is exactly that. Monkey see, monkey do. It's sitting on the carpet as I write - haven't tried any fancy feet yet! Audio jewelry. Well, the sound is very noticeably clearer. In your dreams, but whatever. A CD-Rom vibrates quite a bit in your hand, so I guess this is dampening it usefully. You'd have a lot to think about if you did any reasonble testing, subjective or technical. The most noticeable thing is that louder passages are less congested and shouty - they have soothed out audibly. You'd have a lot to think about if you did any reasonble testing, subjective or technical. Now I have no idea why resonances affect CD transports, but this is without any doubt what I'm hearing - change the damping, change the sound. I suppose this is back to the debate whether 'bits are bits' or whether the signal is complex and affected by other factors. No, you're hearing your preconceived notions which are BTW, faulty. Since it isn't hard to try, maybe somebody else would like to replicate bolting a CD-rom down to a 10mm slab of alu? Anybody with the time to waste... I wonder if the measurements would be different on any parameters. I could tell you how to easily do a representative set of measurements, but it would be a cosmic waste of my time because you're so far gone on your radical subjectivism that you'd never stop mentally masturbating long enough to do them. |
CD transports and resonance
In article , Andy Evans
wrote: Following on from previous posts where I found that various damping materials affected the sound of my Pioneer CDP used as transport only (I have an outboard DAC), I've found the same with the CD-Rom I'm now using. I have also recently added damping material into my Meridian 200 transport and feel this improves the results. However this seems to be due to a reduction in the low level mechanical 'buzz' that was previously *just* audible now being utterly inaudible. Doubt it had any effect on the actual S/PDIF stream emerging from the transport. Hence I suppose it is possible you have encountered something similar. [snip] . A CD-Rom vibrates quite a bit in your hand, Indeed. However when spinning at speeds above x1 it can re-read the disc to ensure consistent and reliable data recovery before sending out the resulting bitstream. so I guess this is dampening it usefully. No idea. The most noticeable thing is that louder passages are less congested and shouty - they have soothed out audibly. Now I have no idea why resonances affect CD transports, but this is without any doubt what I'm hearing - change the damping, change the sound. You may have no doubts, but I in turn doubt this guarantees your perceptions are reliable guides as to any 'cause' of what you beleive may be occurring. :-) I suppose this is back to the debate whether 'bits are bits' or whether the signal is complex and affected by other factors. Since it isn't hard to try, maybe somebody else would like to replicate bolting a CD-rom down to a 10mm slab of alu? I wonder if the measurements would be different on any parameters. To find out: Try making some relevant measurements! Then tell us the results. In principle, vibrations can make it harder for a transport to recover the data from the disc, and there will always be a finite error rate. In practice the actual recovery with a decent transport should be highly reliable in normal use. Can't say much more without some relevant *measurements*. So in principle. Some bit errors may be emerging. Some jitter may be affecting the result. But in practice this seems questionable. To resolve, employ suitable measurements. Otherwise we (including you) have no real idea if the effects you describe have anything to do with the 'causes' you assume. Slainte, Jim -- Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html |
CD transports and resonance
mick wrote:
I read somewhere (sorry, can't give a ref) that the error correction on transports intended for audio is more lax than on those intended for data, as your ears are incapable of detecting low error rates but are more sensitive to the gaps caused by error correction. If that is so, then using a data drive for audio may give a different sound, but not one that is necessarily "better" as it will contain a different sort of inaccuracy! I'm sure someone will be able to correct me on this if I'm wrong. Thats wrong, however IIRC there is less error correction *data* on the CDs themselves for redbook audio than an ISO9660 disc. |
CD transports and resonance
In article ,
Andy Evans wrote: We're talking engineering here - Fays metals, Chiswick. You're talking engineering *materials*, not engineering. The difference is quite audible, as I said, so I'm interested in knowing how resonance dampening affects CD transports. It can only have an effect if the transport is subjected to external vibration sufficient to make it miss-track in some way. -- *Work like you don't need the money. Love like you've never been hurt. Dave Plowman London SW To e-mail, change noise into sound. |
CD transports and resonance
I could tell you how to easily do a representative set of measurements(AK)
But evidently you can't explain an obviously audible phenomenon. === Andy Evans === Visit our Website:- http://www.artsandmedia.com Audio, music and health pages and interesting links. |
CD transports and resonance
In article ,
Andy Evans wrote: But evidently you can't explain an obviously audible phenomenon. Trouble is, Andy, most of your posts concern 'audible phenomenon' that only you can hear... -- *Born free...Taxed to death. Dave Plowman London SW To e-mail, change noise into sound. |
CD transports and resonance
On Sat, 06 Nov 2004 09:07:13 +0000, Ian Molton wrote:
mick wrote: I read somewhere (sorry, can't give a ref) that the error correction on transports intended for audio is more lax than on those intended for data, as your ears are incapable of detecting low error rates but are more sensitive to the gaps caused by error correction. If that is so, then using a data drive for audio may give a different sound, but not one that is necessarily "better" as it will contain a different sort of inaccuracy! I'm sure someone will be able to correct me on this if I'm wrong. Thats wrong, however IIRC there is less error correction *data* on the CDs themselves for redbook audio than an ISO9660 disc. Cheers, Ian. I wasn't sure - it was a while ago that I read the item & I've no idea where I saw it. My memory is c**p... ;-) -- Mick (no M$ software on here... :-) ) Web: http://www.nascom.info |
CD transports and resonance
The difference is quite audible, as I said, so I'm interested in knowing how
resonance dampening affects CD transports. It can only have an effect if the transport is subjected to external vibration sufficient to make it miss-track in some way.(DP) Why not internal vibration? This is considerably larger than anything external. As I've said, the effect of damping the motor vibrations by fixing it to an alu slab is most audible in highly modulated passages. This should give a clue to something. Andy === Andy Evans === Visit our Website:- http://www.artsandmedia.com Audio, music and health pages and interesting links. |
CD transports and resonance
In article ,
Andy Evans wrote: It can only have an effect if the transport is subjected to external vibration sufficient to make it miss-track in some way.(DP) Why not internal vibration? This is considerably larger than anything external. As I've said, the effect of damping the motor vibrations by fixing it to an alu slab is most audible in highly modulated passages. This should give a clue to something. The only clue it gives me is that you're endowing digital apparatus with analogue symptoms. -- *Despite the cost of living, have you noticed how it remains so popular? Dave Plowman London SW To e-mail, change noise into sound. |
CD transports and resonance
I have no wish to 'endow' (DP) anything. I'm reporting less distortion in
highly modulated passages when a transport is damped. So far I've had no explanation. I don't mind if this is outside the subjective technical knowledge of posters - our knowledge always has its limits. === Andy Evans === Visit our Website:- http://www.artsandmedia.com Audio, music and health pages and interesting links. |
CD transports and resonance
Andy Evans wrote:
I have no wish to 'endow' (DP) anything. I'm reporting less distortion in highly modulated passages when a transport is damped. So far I've had no explanation. I don't mind if this is outside the subjective technical knowledge of posters - our knowledge always has its limits. You are using a cdrom drive and an external DAC? How about a little experiment: Fit it into a PC. Copy an audio track as a .wav file with and without damping, then repeat with your stereo system playing some heavy metal turned up to 11. Alternatively connect the digital output to a soundcard with digital input. I would be interested to find whether there was a bit of difference between the files. -- Eiron. |
CD transports and resonance
In article ,
Andy Evans wrote: I have no wish to 'endow' (DP) anything. I'm reporting less distortion in highly modulated passages when a transport is damped. So far I've had no explanation. I don't mind if this is outside the subjective technical knowledge of posters - our knowledge always has its limits. Rather a patronising statement since it also assumes you've discovered something the designers of the device didn't understand either. You're reporting what you *think* you've heard. Until you can support it with proper repeatable and verifiable results, it remains just that. -- *Wrinkled was not one of the things I wanted to be when I grew up Dave Plowman London SW To e-mail, change noise into sound. |
CD transports and resonance
"Andy Evans" wrote in message
I could tell you how to easily do a representative set of measurements(AK) But evidently you can't explain an obviously audible phenomenon. Andy, as long as you're doing such childishly simple, and devilishly flawed listening evaluations, there's no assurance that there is in fact an audible phenomenon. How many ways have I already told you this? |
CD transports and resonance
"Dave Plowman (News)" wrote in message
In article , Andy Evans wrote: But evidently you can't explain an obviously audible phenomenon. Trouble is, Andy, most of your posts concern 'audible phenomenon' that only you can hear... No doubt, its all an illusion. Poor Andy has never heard of "Constructor's ear" even though he is obviously experiencing it. |
CD transports and resonance
"Andy Evans" wrote in message
The difference is quite audible, as I said, so I'm interested in knowing how resonance dampening affects CD transports. It can only have an effect if the transport is subjected to external vibration sufficient to make it miss-track in some way.(DP) Agreed. Why not internal vibration? This is considerably larger than anything external. As I've said, the effect of damping the motor vibrations by fixing it to an alu slab is most audible in highly modulated passages. This should give a clue to something. Andy All we know right now Andy is that your listening evaluation procedures are highly-flawed. |
CD transports and resonance
there's no assurance that there is in fact an audible phenomenon.
Apart from the fact that I can hear it. There's no assurance that you have any technical knowledge that can explain it. I don't mind the fact that you can't explain it - our knowledge always has limitations. === Andy Evans === Visit our Website:- http://www.artsandmedia.com Audio, music and health pages and interesting links. |
CD transports and resonance
In article ,
Andy Evans wrote: there's no assurance that there is in fact an audible phenomenon. Apart from the fact that I can hear it. I'm afraid that's only a 'fact' to you. To be certain it's not just your imagination requires proper testing. Fooling oneself that a 'tweak' produces an audible improvement is as old as tweaks themselves. -- *Proofread carefully to see if you any words out or mispeld something * Dave Plowman London SW To e-mail, change noise into sound. |
CD transports and resonance
On Sat, 06 Nov 2004 13:52:46 +0000, Dave Plowman (News) wrote:
In article , Andy Evans wrote: there's no assurance that there is in fact an audible phenomenon. Apart from the fact that I can hear it. I'm afraid that's only a 'fact' to you. To be certain it's not just your imagination requires proper testing. Fooling oneself that a 'tweak' produces an audible improvement is as old as tweaks themselves. Don't feel bad about this, Andy. I think I can safely say that we have *all* gone through this. It appears that human hearing is easily fooled by psychological factors that have *nothing* to do with the sound waves entering the ear. Hi-fi manufacturers and magazines depend on this for their living... -- Mick (no M$ software on here... :-) ) Web: http://www.nascom.info |
CD transports and resonance
Don't feel bad about this, Andy. I think I can safely say that we have
*all* gone through this. It appears that human hearing is easily fooled by psychological factors Hello Mick - I'm a psychologist specialising in music and musicians, as it turns out, so I'm not unfamiliar with psychological factors! Anyway, to start from the beginning - I sought to replicate the CD transport of Japanese designer Junji Kimura, who worked for Pioneer, Trio and Kyocera. He uses a thick aluminium slab to support the transport. See http://www.soundstage.com/revequip/4...rogression.htm I talked to this guy at the London HiFi Show. He is quite eccentric, but definitely recommended mounting the transport on an alu slab. I was using a CD-ROM at home which was rather 'shouty'. I changed the switchmode PSU for a normal toroid, which helped a bit, then mounted the unit on an alu slab, which helped more, particularly smoothing out highly modulated pasages. If you pick up a CD-ROM while it's playing you can feel the vibrations quite clearly, so we know that there is vibration present. Now, to my ears there was a significant change in the sound, not just a slight change which I would - just as you say - be sceptical about and attribute to 'causes unknown'. I posted this in case it was of some use to other ng members - its useful to hear about various tweaks even if they might not be relevant or replicable in one's own system. Fine. But I also asked if anyone else had an explanation or empirical evidence of the effects of damping on CD mechanisms. I've had various responses, none of which are based on empirical evidence of exactly that. So if this is outside the experience of those posting, It would be honest and simple to say "Sorry, Andy, I don't have any experience of this". Since I would be interested in some empirical knowledge, I'll post this on other forums and ask some of my friends in the audio industry. As I said at the start, this is based on an actual product, the designer of which clearly does have empirical knowledge. === Andy Evans === Visit our Website:- http://www.artsandmedia.com Audio, music and health pages and interesting links. |
CD transports and resonance
To resolve, employ suitable measurements. Otherwise we (including you) have no
real idea if the effects you describe have anything to do with the 'causes' you assume. Hello Jim - I'm open minded - my assumption is that it's to do with resonance, I suppose, but I've been very clear in saying I don't understand how this happens. I'm not in a position to measure, so my next step is to find others who have observed similar things and others who can offer some kind of explanation based on their own empirical knowledge. Andy === Andy Evans === Visit our Website:- http://www.artsandmedia.com Audio, music and health pages and interesting links. |
CD transports and resonance
In article , Andy Evans
wrote: I have no wish to 'endow' (DP) anything. I'm reporting less distortion in highly modulated passages when a transport is damped. Not quite. You are reporting that you think you can hear a difference. However you are not actually providing any evidence that would tell us either: A) If the difference is real. or B) what its nature or cause (if real) might be. So far I've had no explanation. I don't mind if this is outside the subjective technical knowledge of posters - our knowledge always has its limits. The difficulty is not with the lack of technical (or subjective) knowledge of others. The difficulty is that your descriptions don't give us much in the way of reliable or relevant data that would allow others to make a plausible diagnosis. This does not mean that we can all be certain the difference is entirely imaginary. Simply that we have no real way of telling much beyond noting that you think you hear something. Then putting this into the context where some of us generally may not hear the differences you claim in apparently similar circumstances in our own experience. This represents one of the fundamental problems with 'subjective' options which do not come with either any relevant measurements or a plausible physical hypothesis. The subjective 'discription' you give has no clear information content for anyone who was not using your ears at the time, or who does not already by some other means know exactly what you are talking about. I'm afraid that if you want to actually understand what may be the cause of what you hear, and how systematic advice or diagnosis may be given, then you may have to move beyond simply giving a subjective comment. Otherwise I'm afraid that you do not give others any real basis for providing much help. Slainte, Jim -- Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html |
CD transports and resonance
In article , Andy Evans
wrote: there's no assurance that there is in fact an audible phenomenon. Apart from the fact that I can hear it. Or, rather, you *think* you can hear a difference and *assume* it is associated with what you describe. However your descriptions don't really provide any information that could be used as the basis for assessing if any specific 'explanation' was plausible. There's no assurance that you have any technical knowledge that can explain it. I don't mind the fact that you can't explain it - our knowledge always has limitations. Equally, we have no assurance that your descriptions are a reliable guide to what actually may be occurring. If you can't provide reliable and relevant data, why should you expect anyone to be able to offer any explanation? Consider walking into a jeweller's shop and saying, "My watch doesn't keep time. Tell me exactly what's wrong with it." But then declining to either provide the watch for examination or answer the jeweller's questions, or carry out any test he may suggest. Would you expect him to tell you what was wrong with the watch? Slainte, Jim Slainte, Jim -- Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html |
CD transports and resonance
In article , Andy Evans
wrote: [snip] If you pick up a CD-ROM while it's playing you can feel the vibrations quite clearly, so we know that there is vibration present. Now, to my ears there was a significant change in the sound, not just a slight change which I would - just as you say - be sceptical about and attribute to 'causes unknown'. I posted this in case it was of some use to other ng members - its useful to hear about various tweaks even if they might not be relevant or replicable in one's own system. Fine. You may recall that in response I posted details of some damping, etc, I'd applied to a player of my own. Along with which I suggested possible reasons for a change. But I also asked if anyone else had an explanation or empirical evidence of the effects of damping on CD mechanisms. See above. I've had various responses, none of which are based on empirical evidence of exactly that. See above. So if this is outside the experience of those posting, See above. Also consider the possibility that the problem is that you have given others no real information which would permit a plausible diagnosis to be suggested. It would be honest and simple to say "Sorry, Andy, I don't have any experience of this". Alternatively, you could note that some of us do have some 'experience' of some effects that *might* be relevant, but that we can't really say as you have not provided us with any evidence or information that would allow us to decide. i.e. perhaps the problem is primarily due to the lack of relevant info you have given... I'm afraid, Andy, that you will keep encountering effects which will seem to you like "mysteries of science" until such time as you wish to put the required time and effort into being able to make relevant tests and collect relevant evidence that would allow a systematic explanation to be established in a reliable manner. Without this info, there is not much other can do by guess or try things at random. I'm afraid this is really why some people fail to take your reports very seriously. I'd very much like to help, but I reget to say that you do make this somewhere between 'difficult' and 'impossible' at times by the way you proceed, and describe what you think is happening. :-/ Slainte, Jim -- Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html |
CD transports and resonance
On Sat, 06 Nov 2004 14:29:18 +0000, Andy Evans wrote:
Don't feel bad about this, Andy. I think I can safely say that we have *all* gone through this. It appears that human hearing is easily fooled by psychological factors Hello Mick - I'm a psychologist specialising in music and musicians, as it turns out, so I'm not unfamiliar with psychological factors! Anyway, to grin start from the beginning - I sought to replicate the CD transport of Japanese designer Junji Kimura, who worked for Pioneer, Trio and Kyocera. He uses a thick aluminium slab to support the transport. See http://www.soundstage.com/revequip/4...rogression.htm I talked That's one interesting-looking setup... to this guy at the London HiFi Show. He is quite eccentric, but definitely recommended mounting the transport on an alu slab. I was using a CD-ROM at home which was rather 'shouty'. I changed the switchmode PSU for a normal toroid, which helped a bit, then mounted the Now that I can understand. The psu may be letting noise through to the DAC. unit on an alu slab, which helped more, particularly smoothing out highly modulated pasages. If you pick up a CD-ROM while it's playing you That's the bit that makes me a bit sceptical - I'm not denying that you may be right. Its just that without *measurements* you are unlikely to convince many people. can feel the vibrations quite clearly, so we know that there is vibration present. Now, to my ears there was a significant change in the I agree about the vibration. I would suspect that the system would have been designed to handle it in the first place though. sound, not just a slight change which I would - just as you say - be sceptical about and attribute to 'causes unknown'. I posted this in case I don't have access to large lumps of ali, but I may be able to get a lump of 6mm steel plate to try something similar. It should give a suitable bit of inertia to the system... it was of some use to other ng members - its useful to hear about various tweaks even if they might not be relevant or replicable in one's own system. Fine. But I also asked if anyone else had an explanation or empirical evidence of the effects of damping on CD mechanisms. I've had various responses, none of which are based on empirical evidence of exactly that. So if this is outside the experience of those posting, It would be honest and simple to say "Sorry, Andy, I don't have any experience of this". Since I would be interested in some empirical Fine! "Sorry, Andy, I don't have any experience of this". I might give it a go though! After all, I have an old CDR drive and it wouldn't be all that hard to rig it up with and without a lump of steel plate to add mass. knowledge, I'll post this on other forums and ask some of my friends in the audio industry. As I said at the start, this is based on an actual product, the designer of which clearly does have empirical knowledge. I'm afraid that I'm a bit sceptical about some of the product designers - especially those who produce "new wave art" appearance equipment at high prices. I have this horrible suspicion that they may well be selling brand X snake oil... Sometimes I'm wrong. The Michell Gyrodeck is really excellent and that is rather odball in appearance! -- Mick (no M$ software on here... :-) ) Web: http://www.nascom.info |
CD transports and resonance
I'm afraid that I'm a bit sceptical about some of the product designers (mick)
I don't think it's the product designers so much as the tweakers. I'm sceptical myself - it seems paradoxical that resonance can effect binary code. === Andy Evans === Visit our Website:- http://www.artsandmedia.com Audio, music and health pages and interesting links. |
CD transports and resonance
mick wrote:
I don't have access to large lumps of ali, but I may be able to get a lump of 6mm steel plate to try something similar. It should give a suitable bit of inertia to the system... If my fag-packet spreadsheet calculations are correct, Andy's lump of aluminium weighs about 1kg, and a piece of 6mm steel of the same area is about 1.8kg. (I converted his inch dimensions to 165x240mm.) -- Wally www.artbywally.com www.wally.myby.co.uk |
CD transports and resonance
mick wrote:
Thats wrong, however IIRC there is less error correction *data* on the CDs themselves for redbook audio than an ISO9660 disc. Cheers, Ian. I wasn't sure - it was a while ago that I read the item & I've no idea where I saw it. My memory is c**p... ;-) Glad to be of help. |
CD transports and resonance
Andy Evans wrote:
I could tell you how to easily do a representative set of measurements(AK) But evidently you can't explain an obviously audible phenomenon. Can I ask you a question? Do you believe that if on two successive runs, if a CD transport recovers the same bit pattern, the resultant sound will be the same? If so then your simple test would be to compare the bitpatterns on two runs, one silent output, the other cranked to the max, and if they are the same, you must agree there is no effect to observe. If they differ, you have a defective CD transport. |
CD transports and resonance
Andy Evans wrote:
Apart from the fact that I can hear it. There's no assurance that you have any technical knowledge that can explain it. I don't mind the fact that you can't explain it - our knowledge always has limitations. Your ear is a transducer - pressure to electrical impulses. we have mics available that can hear stuff humans cant (demonstrably - animals can hear the difference in the recordings where humans cant) therefore the tool to measure your claimed effect is available. either prove it or **** off. |
CD transports and resonance
Andy Evans wrote:
If you pick up a CD-ROM while it's playing you can feel the vibrations quite clearly, so we know that there is vibration present. Now, to my ears there was a significant change in the sound, Guys I figured it out... when he picks it up it pulls the phonos out ;-) |
CD transports and resonance
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CD transports and resonance
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CD transports and resonance
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