jneutron said:
Heavens no, I didn't mean you.
How do we know? Or to re-phrase, by what authority is that judgment made? Like so many here my background is technological and neither my B.A.Sc. EE nor 25 years in an audio related industry grant me any to make that call. Opinion, yes. Judgement, no. From my perspective we're all dilettantes on this bus and simply writing off Peter's report as 'ridiculous' brings nothing to the table either. It has been effective in shutting down a potentially interesting thread, even if only as a hypothetical case.
Hi John,
Thanks for such carefully-considered remarks about my earlier comments.
If I was as "rude" as you put it, I would simply answer your initial comments with a simple "If the cap fits, wear it, but if not why are you personally so up-tight about it?"
However, I was not referring to you, and my intention was certainly not to be offensive in any way, neither then nor now, and indeed to avoid any personal offence to any individuals, I deliberately avoided any specific references, such as:
"In the bronze age sound more sweeter", "This is all a joke right", "no worry the bird flu should take care of that", "When the moon is in line with the earth", to quickly pick a random few, but there are many others which have been posted earlier, which simply ridicule this thread, precisely as I said.
For the sake of peace, I will not make any comments on anyones' "civility", as you put it.
Returning to the topic, I may not have the advantages you have had in actually manufacturing semi-conductors, but during my 40 yrs. of using them, I have seen the insides of a few which were blown apart through failure or mis-use, and to satisfy my curiosity I have split open a few deliberately. So thank you for your kind assistance here, but I am not a complete electronic dunce, even though experiences have taught me that accepting conventional views or wisdom *on all occasions* is not always the best way to benefit from components in use.
I stand firmly behind my comments on proximity of metals to electronic components and other parts of sensitive circuits, where ultimate sonics achievable from audio circuits are concerned, and I don't mind if you are, or are not, in agreement with me in this as your experiences here have clearly been different from mine. I just know what I hear, but have not managed to measure anything significant to support this particular phenomenon so far.
However, on the device vibration issue I have made some worthwhile measurements which support my beliefs, and, so far, your comments have done little to persuade me of the error of my ways. In fact, I find it hard to believe that when considering a factor in orders of magnitude of differences when considering the relative thickness of the device's plastic case compared with the additional varnish skin, it is not easy for me to accept that capacitance is (entirely) responsible here, precisely as I said.
Whilst I didn't carry out this particular test, myself, similar effects were measured with an Audio Precision test set-up, and it transpired that higher level, odd order harmonics were apparently being suppressed in the 'treated' case, and this would be likely to be the reason for the sonic improvement here, but this still does not satisfactorily prove the cause of this to my entire satisfaction. I regret that (presently) I do not know why vibration should affect any harmonics, and it is not intuitive to me, either.
A relevant test I did personally conduct (many times) was to place a sensor on the body of output devices, and hook this up to a 'scope to see what happened. The sensor was made from an old ceramic cartridge (the kind we used 40yrs ago to listen to records, and before magnetics were available) and with the cantilever placed on an output device, it is surprising what can be deduced from its output.
Being already well aware of the manufacturer's torque ratings for attaching devices, thank you, what I didn't say before is that frequently I found better sonic, and *measurable* results from using lesser settings here than the manufacturers would have us use. There was always a direct correlation betwen the two, and wherever I could reduce measurable internal 'signal-induced' vibrations, I found better sonic results. This, of course was done by way of different heatsink materials, different thermal pads, and varying the devices' respective mounting-screw torque settings. The manufacturers often-touted 8kg.cm for TO3 devices was always on the high side here
for example, and better results were seen (or heard) with reducing this to 6, or even less.
Similarly, as I also said, using different heatsink materials, alternative pads and different torques, appropriately, also affected the sonic results as well.
I couldn't agree with you more when you say "observation is important"! That is precisely what I found, here, too.
Although my temp. measurements were admittedly less accurate, I never saw any direct relationship here with sonic differences, but generally it lead to my using devices with a highish SOA, and de-rating anything appropriately as there could (possibly would) have been some less-effective heat transfer when using reduced screw-torques, as mentioned.
Manufacturers need to err on the side of caution when making application recommendations, but it doesn't automatically follow that any manufacturer knows all there is to know about his products, as they are (quite understandably) not always motivated to carry out years of careful listening tests on them, as I have done in certain instances.
You may not agree with all that I have said, John, but please don't dissuade others who might be interested in this rather unusual phenomenon, from trying out some experiments for themselves.
That would not be in anyone's best interests, and I would be pleased to hear from anyone else who has done some trials along the same lines, and maybe even didn't find similar results. That, to me, would be worthwhile discussing.
Regards,🙂
Thanks for such carefully-considered remarks about my earlier comments.
If I was as "rude" as you put it, I would simply answer your initial comments with a simple "If the cap fits, wear it, but if not why are you personally so up-tight about it?"
However, I was not referring to you, and my intention was certainly not to be offensive in any way, neither then nor now, and indeed to avoid any personal offence to any individuals, I deliberately avoided any specific references, such as:
"In the bronze age sound more sweeter", "This is all a joke right", "no worry the bird flu should take care of that", "When the moon is in line with the earth", to quickly pick a random few, but there are many others which have been posted earlier, which simply ridicule this thread, precisely as I said.
For the sake of peace, I will not make any comments on anyones' "civility", as you put it.
Returning to the topic, I may not have the advantages you have had in actually manufacturing semi-conductors, but during my 40 yrs. of using them, I have seen the insides of a few which were blown apart through failure or mis-use, and to satisfy my curiosity I have split open a few deliberately. So thank you for your kind assistance here, but I am not a complete electronic dunce, even though experiences have taught me that accepting conventional views or wisdom *on all occasions* is not always the best way to benefit from components in use.
I stand firmly behind my comments on proximity of metals to electronic components and other parts of sensitive circuits, where ultimate sonics achievable from audio circuits are concerned, and I don't mind if you are, or are not, in agreement with me in this as your experiences here have clearly been different from mine. I just know what I hear, but have not managed to measure anything significant to support this particular phenomenon so far.
However, on the device vibration issue I have made some worthwhile measurements which support my beliefs, and, so far, your comments have done little to persuade me of the error of my ways. In fact, I find it hard to believe that when considering a factor in orders of magnitude of differences when considering the relative thickness of the device's plastic case compared with the additional varnish skin, it is not easy for me to accept that capacitance is (entirely) responsible here, precisely as I said.
Whilst I didn't carry out this particular test, myself, similar effects were measured with an Audio Precision test set-up, and it transpired that higher level, odd order harmonics were apparently being suppressed in the 'treated' case, and this would be likely to be the reason for the sonic improvement here, but this still does not satisfactorily prove the cause of this to my entire satisfaction. I regret that (presently) I do not know why vibration should affect any harmonics, and it is not intuitive to me, either.
A relevant test I did personally conduct (many times) was to place a sensor on the body of output devices, and hook this up to a 'scope to see what happened. The sensor was made from an old ceramic cartridge (the kind we used 40yrs ago to listen to records, and before magnetics were available) and with the cantilever placed on an output device, it is surprising what can be deduced from its output.
Being already well aware of the manufacturer's torque ratings for attaching devices, thank you, what I didn't say before is that frequently I found better sonic, and *measurable* results from using lesser settings here than the manufacturers would have us use. There was always a direct correlation betwen the two, and wherever I could reduce measurable internal 'signal-induced' vibrations, I found better sonic results. This, of course was done by way of different heatsink materials, different thermal pads, and varying the devices' respective mounting-screw torque settings. The manufacturers often-touted 8kg.cm for TO3 devices was always on the high side here
for example, and better results were seen (or heard) with reducing this to 6, or even less.
Similarly, as I also said, using different heatsink materials, alternative pads and different torques, appropriately, also affected the sonic results as well.
I couldn't agree with you more when you say "observation is important"! That is precisely what I found, here, too.
Although my temp. measurements were admittedly less accurate, I never saw any direct relationship here with sonic differences, but generally it lead to my using devices with a highish SOA, and de-rating anything appropriately as there could (possibly would) have been some less-effective heat transfer when using reduced screw-torques, as mentioned.
Manufacturers need to err on the side of caution when making application recommendations, but it doesn't automatically follow that any manufacturer knows all there is to know about his products, as they are (quite understandably) not always motivated to carry out years of careful listening tests on them, as I have done in certain instances.
You may not agree with all that I have said, John, but please don't dissuade others who might be interested in this rather unusual phenomenon, from trying out some experiments for themselves.
That would not be in anyone's best interests, and I would be pleased to hear from anyone else who has done some trials along the same lines, and maybe even didn't find similar results. That, to me, would be worthwhile discussing.
Regards,🙂
My turn to say heavens, no..rdf said:
I do not consider it acceptable to simply brush off observations. Case in point:glop over the package and torque..
My point was it is not acceptable to call others names because they consider an assertion ridiculous. I should have clearly earmarked "ridiculous assertion" as "what they perceive as.., so in that I didn't make myself clear enough....good call on your part.
Look at the stuff I've posted..I'm confident that many others consider my assertions as ridiculous, and discussion ensues. But I don't call them names because they consider what I've asserted as "silly". I'll try to explain, but that's what this forum is supposed to be all about.
It was not my intent to call Peter's assertions as ridiculous. The explanation of vibe and damping and such, I certainly don't agree with, said so, and provided an alternative explanation to explain what he observed..but I didn't tell him he's dreaming up what he claims to have heard.
Cheers, John
I'm not sure temperature is the right tree to bark up, otherwise we would have a large following on people who would only test their amps on sunny days.
Well, as I've been told, perhaps my remarks in that regard were not so carefully considered. My apologies for my over-reaction.Bobken said:
Yes, some of the comments of others were not worthy of the light of day..
Anyone who hasn't experienced that is simply not pushing the envelope.Bobken said:
Bobken said:
That was certainly not my intent. Not too many people have any experience in the silicon chip end of this stuff, so I don't expect many to know what's "under the hood"
I believe that statement is requisite for any paradigm shift. No paradigm shift, no moving forward.Bobken said:
Perhaps you should re-read what I wrote. I was pointing out an instance where a state of the art manufacturer, teledyne philbrick, used proximity to components to gain a real, measureable market advantage over other state of the art manufacturers. I am not concerned that you have not measured anything to support this assertion, and in fact, provided a real life instance where what you are saying was indeed seen, measured, and duplicated..for years.Bobken said:
You did not provide any measurements in support of a vibration argument, so I cannot comment on what they are.Bobken said:
I would caution that many times, what is considered as being the cause is in fact not, but only something that correlates.
The thickness of the plastic overmolding is not actually the thickness of the device. The wirebonds on the chip rise considerably off the surface of the silicon, so the wires themselves can be as little as 10 to 20 thousanths of an inch below the surface of the plastic, and the top surface of the chip can also be very close to the surface. Typically, if the die is placed directly onto the 60 mil tab (sorry not to use metric units) and the die is 35 mils with a soft solder attach, the top of the die is about 100 mils off the bottom of a non isolated case. The device in my hand, an LM3876, is 170 mils thick. The silicon is 70 mils under the plastic, the wires bonded to that silicon will rise above it at least 2 to 5 wire diameters, which leaves very little headroom for a 10, 15, or 20 mil aluminum wire attached to the chip..as I said, the wires in these devices are incredibly close to the surface of the plastic.Bobken said:
The molding plastic is not specified for high capacitance, it is preferred to use plastic with as low a DC as possible.
Ah, second hand accounts can be notoriously aggravating, as the entire story sometimes gets lost.Bobken said:
Adding gate to source capacitance can certainly alter circuit operation, I'm sure we all agree. Whether the test you cite was conducted in a controlled and rigorous manner, who knows..
What a really novel and fun way to do it. I like it.Bobken said:
We are working with piezo based xducers here, we need to measure vibe down at the sub nanometer realm (atom scale movements). It's ongoing work, and really fun.
What I would have cautioned against is the fact that you were placing an electrical device, with conductive loops, in the proximity of a power device which is carrying large rate of change of current throughout. As such, how can you be sure what you saw was direct measurement of vibration and not electrical pickup. This, we are very concerned with here.
I have to note, that I have heard output devices sing in response to pushing a resistive load, two things occurred..First, the wirebonds in the TO-3 cases were flexing due to the current, and I suspect the heatsinks were constricting as a result of eddy currents caused by the output devices.
Bobken said:
Again, I would caution against mistaking correlation with causation
Measurement of the sink or device plastic surface doesn't correlate well with the transfer resistance beneath the device, so I wouldn't expect you to find significant correlation, as you couldn't get to the actual chip temperature.Bobken said:
Bobken said:
I have not dissuaded anyone. I point out the need to be observant, diligent, and question all explanations, mine included.. As well as the need to consider all the confounding variables which are not controlled when simple experiments are attempted..as I have always found simple experiments usually have some simple confounding influence which bites you in the derrier..
Cheers, John
jneutron said:
Sorry, my writing can be a little dry, especially when I should be focusing on the pile of resumes on the desk 🙂. It's exactly for the reasons you outline your reaction caught my attention. You do make an honest attempt at explanation, you do start by taking reports of this type at their word if past experience appears to warrant it, you don't respond with ridicule or write it off. I guess I'm really picking your brain to get a handle on perspectives here in general. Mine was Bobken's reaction wasn't out of line with much of the thread. But like Bobken says, back to the topic at hand! Thanks for the replies!
I'm with Neutron... too often correlation is confused with causation.
I would suggest that if the elastic properties of the heat sink material actually do affect the sound, audibly, than some other mechanism is at play here... and with that in mind; the wrong problem is being treated.
Can somebody short the inputs on their chipamp, put the amp in another room, tap on the heatsink with a plastic tool, and have second person listen to the speakers?
🙄
I would suggest that if the elastic properties of the heat sink material actually do affect the sound, audibly, than some other mechanism is at play here... and with that in mind; the wrong problem is being treated.
Can somebody short the inputs on their chipamp, put the amp in another room, tap on the heatsink with a plastic tool, and have second person listen to the speakers?
🙄
poobah said:
Who...that neutron grouch???
poobah said:
At the vibe levels we are talking about, that won't find much, I suspect.
The vibe levels will not be enough to cause any effects to the semiconductors, so the only thing left would be relative movement of conductors which are carrying current while moving. With no signal, the quescent currents are far lower than during signal.
I would recomment feeding a signal into a dummy load, say 3/4 power, 1000 hz or so. Then, while examining the output, bonkin against the sinks. If there is any movement, it would be a case of conductors moving while current is within, to produce loop voltages.
If positive, then one needs to determine susceptibility to typical room vibe levels...will it have an audible effect at spl's that do not kill us..(if you have to bonk the sink to get anything, what spl would be needed to re-create that stimulus)
Also, if positive, then one needs to re-create the sink using a laminate structure, to duplicate the modulus while getting rid of eddy currents.
Cheers, John
Bobken said:
Well, since you used my little quote, I will assume that you were thinking of me.
Call me a skeptic, I'll plead guilty on this one. I don't have an EE degree, nor a ton of experience building amplifiers. I do have a business degree though, and I've heard enough marketing and hype to know it when I see it.
I'll just say that if audiophiles hear all they say they can, then we should do away with SONAR on submarines, and just hook up a set of Grados and let them listen. They are bound to hear more 'detail' than those silly computers that can't even measure effects like the one that's being discussed here.
I won't say that there is absolutely zero change due to heatsinks, but I'll wager that the effect is so many orders of magnitudes below our threshold of persception that only dogs and imaginations can hear it.
Or maybe it's that it's just so darned close to April 1st.
P.
pneuma said:
Yes, there is a lot of hype out there. I can understand being skeptical of all claims that seem outlandish.
I agree that computers are silly. But, I can make mistakes on a computer a million times faster than by hand...now that's power.pneuma said:
But alas, a computer can't measure anything, it requires some analog electronics, and a test methodology. One which I have not seen to date that is designed to even try to look for what is being discussed.
pneuma said:
There is of course that possibility, but without testing for it properly, how does one know. Do we keep the separate camps?
These single chip babies are awesome, but there are caveats.
The output current is, what, say 5 amps peak..and yet the input current is measured in microamps. The power gain is HUGE!!!
And yet, the input pair is how far from the output currents??????
250 mils??? Holy cow..how in the name of sam hill do we STOP coupling excitation between the ins and outs??
What shocks me more than anything else, is the lack of e/m considerations that have been applied to using these babies correctly. Yes, they are engineered well enough that guys like us can basically get them to work, but my goodness, current gains of 6 orders of magnitude, voltage gains of 90 dB, absolutely huge power gain, all this in less that a square inch of real estate???
sheesh, I thought my job was tough...
Cheers, John
There's a lot in that amp potentially susceptible to the effects of vibration. The caps are on the sink and I know Peter usually exerts extra effort in their mounting and finish. The autotransformer volume controls come to mind as well, thought mounted into the wood side panels. Heck, it could even relate partially to keeping the caps at a more constant temp through the application of mass. Wouldn't aluminum temp cycle much quicker?
BTW pneuma, Peter mentions it's not a product, just a design study. Can't see how marketing applies.
BTW pneuma, Peter mentions it's not a product, just a design study. Can't see how marketing applies.
rdf said:
I appologize for being a bit broad. I should've made it clearer that what I meant was "This is similar to what I hear when marketing occurs."
So no, I'm not trying to imply that there's something being sold, just that I've got the same bells going off. It's the same feeling I get when someone is telling me how a new plating, porting, or finishing method will yield a paintball barrel that shoots further than ever before possible.
I think that there would be more point in discussing the effect the vibration of my foot tapping along with the beat will have on the amp's function than Al vs Cu vs Brass for the heatsink, as it'll be greater with respect to vibration.
P.
jneutron said:
Ahh, but it's usually the same error a million times, and not a million unique ones.
But alas, a computer can't measure anything, it requires some analog electronics, and a test methodology. One which I have not seen to date that is designed to even try to look for what is being discussed.
Nor would I expect their to be.
There is of course that possibility, but without testing for it properly, how does one know. Do we keep the separate camps?
I suppose I'll stay in the "it does nothing until you can proove it does something" camp, since it's not obvious to me. Obvious or logically inferred things I can routinely accept. Things like this I tend to wait until proof develops. Or I guess I could attach a banana to the outside of my computer and talk about what organic designs it yeilds in Rhino 3d. They will of course get more rotten as time goes on, due to the increase disturbence from the gases the bacteria release. 🙂
P.
[edit]Edited for input idiocy and grammar[/edit]
pneuma,
It does seem that mystique adds so much to it all... you know, we ARE talking about an amp wrapped around a $3 chip...
It does seem that mystique adds so much to it all... you know, we ARE talking about an amp wrapped around a $3 chip...
Too true, but where to draw the line? By the tenets of anyone's Good Book - say, Horowitz and Hill - how is the vast majority of DiyAudio justified? A properly designed speaker with an impedance above 7 ohms, a $3 chip on the manufacturer's assessment board, within its power limits such a system arguably repesents the pinnacle of the reproductive arts by those constraints. About as much fun as playing with a shoe though.
poobah said:pneuma,
It does seem that mystique adds so much to it all... you know, we ARE talking about an amp wrapped around a $3 chip...
Hi,
No offence intended here, but I can see now where I have been going wrong! You see I quite thought the thread was about bronze heatsinks, and what effect they had on the sound of amplifiers. At least that appeared to me to be the motivation for splitting this thread off a while ago.
Personally, I have never built, nor even heard a chip amp, simply because it does not provide the challenges which particularly interest me, but there are many people (not merely DIYers) who are enthusiastic over these amps and I respect their rights to do so.
I would have found this discussion rather more worthwhile and interesting if posters had commented more on the relevant issues here, rather than most of what has gone before, and now there seems to be an apparent subtle shift towards 'chip-bashing', which to me at least, is quite beside the point of the thread.
When I joined the thread it was to share some experiences, most of which were related to this subject, even if not entirely directly, and I referred to my listening trials (and some measurements) which I hoped might throw some light on the sonic changes which Peter had originally exposed.
I then reasonably quietly accepted an unwarranted outburst from someone whom 'Jesus wouldn't have wanted for a sunbeam', as others seemed to consider as well, and several attempts to disagree with everything I said.
None of this especially bothers me, nor what I consider to be a generally patronising, and at some times overbearing, attitude during these disagreements.
However, so far I have seen no direct 'countering' explanations, for example over the 'relaxed' torque settings I (and some audio manufacturers) have found beneficial, which actually were originally dismissed with "... your sonic observations on torque related audibility, your experience directly correlates to *better* thermal management practices... Whilst more than likely not vibration related...."
I have subsequently pointed out that in reality the converse is true, and that my choices here based on listening tests (and my funny vibration measurements) would be likely to have prejudiced the thermal interface, rather than as suggested by the above quote, but certainly could hardly have "bettered" them. It is disappointing to me that in amongst the smokescreen, no-one has yet commented on this particular point, or even said they have carried some relevant tests for themselves, and that either they also agree with my findings, or not.
Another trial I had not yet referred to is that I have deliberately excited output devices with a suitable vibrator, although I am certainly not about to explain how this was constructed or I will possibly receive another thinly-veiled 'put down' along the lines of "how quaint", or something similar. When using this device, it was possible to demonstrate that deliberately vibrating power devices (at least) had an adverse affect on the overall sound of the amp.
I prefer to avoid using soft pads like Silpads, after certain trials were undergone, and I always use either mica or alumn. oxide of late. I don't happen to know their Brinel hardness off the top of my head, but they are, to all practical intents, extremely hard and non-compressible. When using these pads and backing off screws by a fraction of a turn which is all that happens in practice when reducing from say 8 to 5 or maybe 6 kg.cm of torque for the mounting screws, there is no measurable relative movement between the device and the heatsink, either.
On the other hand, what there most certainly will be is a reduced force acting to pull these parts together, and this does most certainly have an effect on the vibration of the device attached to the sink. Normally, the sink will have a mass which is many orders of magnitude higher than that of any attached device, and will accordingly have a considerably lower natural period of resonance than relatively tiny transistors. When the two parts are very securely attached to each other, they will then tend to vibrate *together* at a new frequency which results from the combined masses, but will be much lower, and in fact fractionally lower than the heatsink, alone.
It is my belief that when the devices are strapped less hard on to this massier heat sink, and with probably a 'lossier' interface as well, that the vibrational energy is reduced somewhat due to damping effects, and being at a considerably different frequency, this will be the cause of the sonic effects I have heard. Of course, any change in heatsink materials (like going over to bronze) which will consequently affect their own mass and their inherent damping properties, will then enter the picture too in some way.
Furthermore, just because for brevity I only specifically referred to self-induced vibration effects before, vibration affecting output devices is not restricted to this particular input, and In most cases this self-induced vibration is probably completely swamped by 'external' influences.
Unfortunately it is a 'two-way' effect, and ground-borne, transformer-induced, and especially air-borne vibrations (speaker feedback) all badly affect sonics, whether we like this or not.
Because I don't like the effect of much metal in proximity to audio circuits, most of my equipment (except sources) is now built on bare open chasses, and this also permits ready modifications to be carried out, too. This is not domestically acceptable, so I have a long low box with one open side made from 3/4" MDF, covered with the same long pile carpet, identical to the dedicated listening room's carpet, and this sits over the majority of my equipment in normal circumstances, directly in front of me. The open back allows for some heat dissipation, and from the room it looks much like a long step at the end of the room, and is quite acceptable.
The point of mentioning this, is that, a long while ago, I realised that the sound was a little better when this box was in place than when I was making some circuit changes and the cover was not in use. Recognising this, I carried out some other trials, and without any doubt the main reason for this improvement was restricting much of the airborne soundwaves (particularly at higher levels) from affecting the heatsinks which have a large surface area, and are made up from multiple thin fins which are inherently almost microphonic it seems.
I won't go into these tests for now, but it was at this stage when I realised I could physically feel (with a gentle touch) certain vibratory effects actually at the output devices, so I don't know quite how this fits in with any earlier suggestions about "atomic levels here", although, of course, the cause of this vibration was probably mainly due to the affect soundwaves and possibly other influences had on the sinks.
Whatever, there is no doubt in my mind that due to several possible causes, and whether or not I happen to fully understand them, different heatsink materials (together with several other associated factors) will make a difference to the sound, as this accords with my experiences, and as Peter has also found out.
Regards,
Re: Re: Libido
Hi Bobken,
No it's not offensive; just that I am just the opposite using way less words.
And I am too lazy to read long posts.
My longest post was a joke! Was it?
http://www.diyaudio.com/forums/showthread.php?s=&threadid=42605&highlight=
Bobken said:
Hi Bobken,
No it's not offensive; just that I am just the opposite using way less words.
And I am too lazy to read long posts.
My longest post was a joke! Was it?
http://www.diyaudio.com/forums/showthread.php?s=&threadid=42605&highlight=
Hey Bobken,
I'm not chip bashing. My point is this, when building a chip amp, the focus shifts towards what one would "wrap around" the chip to make it work. And this does include heat sinks. The DIY designer has little to do with chip itself... pick out 2 resistors and bypass the little guy and you're in business.
The mods pulled this thread out on its own because they feared it would degrade into something akin to a speaker cable thread and thereby detract from Peter's original post. And I would have to agree with all that. Some esoteric issues aside, and Neutrons well placed remarks regarding the poor e/m practices (exibited in nearly all amps... see the blowtorch); Peter builds a pretty fine amp. And I wouldn't care to rake Peter over the coals, because he not selling $1500 power cords. Go to his website... Peter is not ripping anyone off. And like any builder of chips amps, he has no place to exercise fanatical creativity except heat sinks etc...
Now certain people hear things that others can't... and some believe things that other's don't. It's a fine line... but a guy selling a "special" power cord for $30 is well... OK... I guess. But a guy selling $1500 power cords is a liar and a thief. I leave it to you to see the logic in that.
Back to heatsinks, and the same old problem again; its sounds better, but there is no explanation as to why. The first hurdle is always the same... does it REALLY sound better, or was someone's imagination getting the better of them? That's the one that starts the fires and by the time they get roaring no one bothers with the issues of WHY.
I wouldn't contest your claim that a plexi cover on your amp made it sound better. But as an engineer, weren't you curious as to why? Why would un-shielding an amp make it better. Why would plexi win over air? What the heck was metal cover doing?
My point? Ignoring the WHYs creates the mystique.
😎
I'm not chip bashing. My point is this, when building a chip amp, the focus shifts towards what one would "wrap around" the chip to make it work. And this does include heat sinks. The DIY designer has little to do with chip itself... pick out 2 resistors and bypass the little guy and you're in business.
The mods pulled this thread out on its own because they feared it would degrade into something akin to a speaker cable thread and thereby detract from Peter's original post. And I would have to agree with all that. Some esoteric issues aside, and Neutrons well placed remarks regarding the poor e/m practices (exibited in nearly all amps... see the blowtorch); Peter builds a pretty fine amp. And I wouldn't care to rake Peter over the coals, because he not selling $1500 power cords. Go to his website... Peter is not ripping anyone off. And like any builder of chips amps, he has no place to exercise fanatical creativity except heat sinks etc...
Now certain people hear things that others can't... and some believe things that other's don't. It's a fine line... but a guy selling a "special" power cord for $30 is well... OK... I guess. But a guy selling $1500 power cords is a liar and a thief. I leave it to you to see the logic in that.
Back to heatsinks, and the same old problem again; its sounds better, but there is no explanation as to why. The first hurdle is always the same... does it REALLY sound better, or was someone's imagination getting the better of them? That's the one that starts the fires and by the time they get roaring no one bothers with the issues of WHY.
I wouldn't contest your claim that a plexi cover on your amp made it sound better. But as an engineer, weren't you curious as to why? Why would un-shielding an amp make it better. Why would plexi win over air? What the heck was metal cover doing?
My point? Ignoring the WHYs creates the mystique.
😎
Hi poohbah,
This will have to be my final attempt, as I am beginning to lose the will to live.
Much of what you have questioned here, I already answered before, as best I could. Several of my comments have been along the lines of there are *differences* to be heard, not necessarily that one thing, or another, sounds better. The varnish I tried was sonically bad, the reducing of transistor mounting screw torques was good, for two examples, and it is certainly not all one way.
I originally said "not always to the good" and "this was one of my aborted trials connected with audio, of which there have been many others, similarly unsuccessful" and during some 35 yrs of 'listening' trials of all kinds, my success rate in achieving genuine improvements is probably about 3 in 10 maximimum, as I have readily acknowledged elsewhere on this Forum. However, I was happy to expend the necessary time, and accepted the results quite readily, good or bad.
I have had much greater consistency with strictly 'objective' matters and those which do readily fit in with conventional wisdom, and I have been measuring (conventionally) electronic devices and circuits for around 40 yrs now, since originally becoming involved in electronics, albeit not by way of employment in the audio field.
I simply discovered a long while ago that conventional measurements did not explain some of the phenomena I had noticed, and, where possible, attempted to investigate these anomalies. As mentioned recently in a thread about the sound of snubbers, which went much along the lines of this thread, regrettably, I have a foot in 'both camps'. Initially I was a staunch objectivist and 'meter-reader', but later added another 'tool' to my test gear (i.e. my ears, as this appeared to be rather relevant to audio) and latterly benefit from both approaches, where appropriate.
The only reason I 'listened' to the acrylic cover was to determine if the half-expected RFI problems would result from using this non-metallic cover, and I had no expectation, whatsoever, that there could be anything other than a detrimental result here. However, as already carefully explained, the reverse was the outcome, and I was not prepared to ignore this rather inconvenient discovery.
I believed that the additional physical damping to that pre-amp resulting from the addition of over a square foot of 8mm thick acrylic was responsible for this very slight (but still obvious and consistently-repeatable) gain in sonics, but this could have been achieved in several other ways, as I later investigated.
There was no possible reason for any imagination here in the first place, I duly made dozens of careful comparisons over several weeks with the two covers, and I have also posted elsewhere recently that unwitting self-deceit is the enemy of any listening trials.
Of course I wished to know why, and the inevitable conclusion I came to, has been vindicated many times since then by further experiments, and even only yesterday I learned of yet another two audio manufacturers who apparently choose to avoid metal near to their electronic circuits, wherever possible.
When attempting to achieve this most awkward state of affairs, which is extremely difficult in manufacture from the practical standpoint, I cannot help wondering why they do this and make their lives so much more difficult? The conclusion I inevitably reach is that they have discovered what I did some 20 yrs ago, because they simply listened to what happened here, instead of relying on whatever has been accepted practice for years by most others.
Nobody has "ignored any whys" at any stage, although several times I was, admittedly, unable to corroborate some conclusions by any relevant measurements, to my entire satisfaction.
As what I have been sincerely attempting to get over when I originally addressed Peter seems to have merely resulted in even more ill-feeling than when I joined this thread, it is serving no useful purpose to continue this discussion from my point of view.
Regards,🙂
This will have to be my final attempt, as I am beginning to lose the will to live.
Much of what you have questioned here, I already answered before, as best I could. Several of my comments have been along the lines of there are *differences* to be heard, not necessarily that one thing, or another, sounds better. The varnish I tried was sonically bad, the reducing of transistor mounting screw torques was good, for two examples, and it is certainly not all one way.
I originally said "not always to the good" and "this was one of my aborted trials connected with audio, of which there have been many others, similarly unsuccessful" and during some 35 yrs of 'listening' trials of all kinds, my success rate in achieving genuine improvements is probably about 3 in 10 maximimum, as I have readily acknowledged elsewhere on this Forum. However, I was happy to expend the necessary time, and accepted the results quite readily, good or bad.
I have had much greater consistency with strictly 'objective' matters and those which do readily fit in with conventional wisdom, and I have been measuring (conventionally) electronic devices and circuits for around 40 yrs now, since originally becoming involved in electronics, albeit not by way of employment in the audio field.
I simply discovered a long while ago that conventional measurements did not explain some of the phenomena I had noticed, and, where possible, attempted to investigate these anomalies. As mentioned recently in a thread about the sound of snubbers, which went much along the lines of this thread, regrettably, I have a foot in 'both camps'. Initially I was a staunch objectivist and 'meter-reader', but later added another 'tool' to my test gear (i.e. my ears, as this appeared to be rather relevant to audio) and latterly benefit from both approaches, where appropriate.
The only reason I 'listened' to the acrylic cover was to determine if the half-expected RFI problems would result from using this non-metallic cover, and I had no expectation, whatsoever, that there could be anything other than a detrimental result here. However, as already carefully explained, the reverse was the outcome, and I was not prepared to ignore this rather inconvenient discovery.
I believed that the additional physical damping to that pre-amp resulting from the addition of over a square foot of 8mm thick acrylic was responsible for this very slight (but still obvious and consistently-repeatable) gain in sonics, but this could have been achieved in several other ways, as I later investigated.
There was no possible reason for any imagination here in the first place, I duly made dozens of careful comparisons over several weeks with the two covers, and I have also posted elsewhere recently that unwitting self-deceit is the enemy of any listening trials.
Of course I wished to know why, and the inevitable conclusion I came to, has been vindicated many times since then by further experiments, and even only yesterday I learned of yet another two audio manufacturers who apparently choose to avoid metal near to their electronic circuits, wherever possible.
When attempting to achieve this most awkward state of affairs, which is extremely difficult in manufacture from the practical standpoint, I cannot help wondering why they do this and make their lives so much more difficult? The conclusion I inevitably reach is that they have discovered what I did some 20 yrs ago, because they simply listened to what happened here, instead of relying on whatever has been accepted practice for years by most others.
Nobody has "ignored any whys" at any stage, although several times I was, admittedly, unable to corroborate some conclusions by any relevant measurements, to my entire satisfaction.
As what I have been sincerely attempting to get over when I originally addressed Peter seems to have merely resulted in even more ill-feeling than when I joined this thread, it is serving no useful purpose to continue this discussion from my point of view.
Regards,🙂
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