Quite frankly I don't understand why different pads should sound different

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Peter Daniel said:
I'm using TO-220 aluminum oxide pads under LM1875. It works fine and sounds better than silpads (less damping, I guess, results in more airy sound)

I don't understand your rational here. I can't understand why you think less damping is undesirable. I can only think that the "less air" description is more accurate and neutral reproduction, and your "more air" is actually artifacts due to mechanical vibration in the chip, i.e., a euphonic coloration. I don't understand why you choose to spend so much effort balancing so many euphonic colorations. Then, when you change something, you have to go back and start all over again. Why not neutralize the colorations, so you have less variables. I know you think that everything colorizes, but why knowlingly add them?
 
pooge said:
"I'm using TO-220 aluminum oxide pads under LM1875. It works fine and sounds better than silpads (less damping, I guess, results in more airy sound)." Peter Daniel

I don't understand your rational here. I can't understand why you think less damping is undesirable. I can only think that the "less air" description is more accurate and neutral reproduction, and your "more air" is actually artifacts due to mechanical vibration in the chip, i.e., a euphonic coloration. I don't understand why you choose to spend so much effort balancing so many euphonic colorations. Then, when you change something, you have to go back and start all over again. Why not neutralize the colorations, so you have less variables. I know you think that everything colorizes, but why knowlingly add them?


I actually think, that less damping is desirable. And how you know what a neutral reproduction really is? Maybe that's what you get with less damping or more damping, depending on the rest of a setup. There is no simple answer for that. Ever listened to unechoic orchestral rechording? It doesn't have any colorations, but doesn't sound like music either.
 
"I actually think, that less damping is desirable. And how you know what a neutral reproduction really is? Maybe that's what you get with less damping or more damping, depending on the rest of a setup. There is no simple answer for that. Ever listened to unechoic orchestral rechording? It doesn't have any colorations, but doesn't sound like music either."

I think it is simple. By keeping the chip from vibrating, you are causing less generation of noise, or other spurious signals or delayed resonances, from the likes of piezo type generations, etc. This, BY DEFINITION, is more neutral than allowing the chip to vibrate and create spurious colorations, euphonic or otherwize. If you like them, fine. But I don't think you can call these vibrations more accurate or neutral just because you like them better. You are advocating using parts as a tone control. If you don't like the sound with damped components that don't generate spurious euphonics, then maybe should look elsewhere to "fix" things to your liking, and leaving the noise/resonances out of the equation.
I don't think your analogy to unechoic orchestrat recordings apply here. Your are trying to accurately amplify an existing recording. If you add colorations, you are not doing this. If you don't like the result of damped components, maybe it's the recording you should blame (or other weak link). However, if you add resonances by not damping, it seems obvious that finding and fixing other problems will be much more elusive and difficult, and make your amp inherently sensitive to mating with other components.
 
I am not that crazy about adding vibrations, but rather controling and redistributing (because you can't get rid of them completely). Talking specifically here, about insulating pads, none of this pads prevents the chip from vibration. It just happens, that I prefer the sound of a chip with aluminum oxide pad and not silpad. But silpad doesn't eliminate the vibrations from a chip, it just makes it for a different kind.

I sugggest you make some experiments of your own, instead of jumping to the conclusion that damping is a cure for everything. It is simply not. I think it is simple;)

I never mentioned that I want to create an amp that would be a tool for analyzing recordings. Since most of them don't sound that well, there is no reason to do that. I prefer the equipment that makes music. If this is not neutral to you, I don't mind if you don't agree with me.
It is relatively simple to create a neutral sounding amp and there are many of them around. But if you read carefully some better reviews, you will notice that they usually don't try to describe how the amp reproduces the recording, but how well it reproduces the musical notes, little details, acoustic space and soundstage. There are not that many amps that make it really well.

pooge said:
You are advocating using parts as a tone control. If you don't like the sound with damped components that don't generate spurious euphonics, then maybe should look elsewhere to "fix" things to your liking, and leaving the noise/resonances out of the equation.

How do you damp the componenets and make sure that they don't vibrate? And what can you do to leave the resonances out of equasion?
 
I don't recall ever saying that damping is the cure for everything.

You stated damping was the reason for the difference in sound you say you heard. However, as true damping is resistive conversion (i.e. energy removal) rather than energy spreading, I do see a fundamental advantage in that.

Basically, my argument is that you concluded the reason for your preference of one sound over the other is attributed to damping, when the difference you say you heard may not even have anything to do with damping (leaving your followers to believe that neither silpads nor damping is a good thing). Did you do any "experiments" to confirm that this variable alone is the reason for those "differences" you say you heard to make such a conclusion? Why are you trying to throw this burden on me? And please do not hold up your preference as a valid experiment for me to prove wrong.

"I never mentioned that I want to create an amp that would be a tool for analyzing recordings. Since most of them don't sound that well, there is no reason to do that."

True. You never said you were trying to create an accurate amp, just what sounds good to you; and I do not argue this is illegal, immoral, or reprihensible. However, I (and I'm sure many others) do see a reason to do just "that". (BTW, I lean more to the side that defines an accurate amp as one that creates an identical replica of the input, and has the ablity to sink back EMF from a speaker, rather than one that simply tickles my rectum.)

Have fun in your quest for the holy bandaids. (OK, I admit that was a low shot. If you prefer an amp euphonically tuned to you liking, go for it.)
 
pooge said:
You stated damping was the reason for the difference in sound you say you heard. However, as true damping is resistive conversion (i.e. energy removal) rather than energy spreading, I do see a fundamental advantage in that.

Basically, my argument is that you concluded the reason for your preference of one sound over the other is attributed to damping, when the difference you say you heard may not even have anything to do with damping (leaving your followers to believe that neither silpads nor damping is a good thing). Did you do any "experiments" to confirm that this variable alone is the reason for those "differences" you say you heard to make such a conclusion? Why are you trying to throw this burden on me? And please do not hold up your preference as a valid experiment for me to prove wrong.


If you refrained from low shots and read more carefully, you would noticed that it was my guess not a statement. I didn't do extensive experiments in that area, just one try, but my previous findings may actually confirm that it is damping related.

Peter Daniel said:
I'm using TO-220 aluminum oxide pads under LM1875. It works fine and sounds better than silpads (less damping, I guess, results in more airy sound).


It seems like I might learn something from you here. So what exactly you do differently from me, so that your amp can sound more "neutral" and "accurate"?

pooge said:

True. You never said you were trying to create an accurate amp, just what sounds good to you; and I do not argue this is illegal, immoral, or reprihensible. However, I (and I'm sure many others) do see a reason to do just "that". (BTW, I lean more to the side that defines an accurate amp as one that creates an identical replica of the input, and has the ablity to sink back EMF from a speaker, rather than one that simply tickles my rectum.)

 
I can think of absolutely no plausible reason why allowing a component to vibrate to the point that sound is altered (other than a mike or speaker) could possibly make it more accurate or neutral, by definition. I simply cannot believe that keeping a component from vibrating, if it is not a transducer, can have any possible detriment to accuracy. Increases in airyness due to removal of damping strongly implies added or delayed resonances to me; much like that attributed to phono reproduction. That is, of course, if damping is the reason for the change. It might sound more lively, but how can it possibly be more accurate.

As to what I do different: I try to put at least some trust in fundamentals rather than trust my hearing 100%. In other words, if it makes absolutely no sense that allowing a component to vibrate could possibly make it more accurate, I have to presume that the increased airiness I hear should not be there. I don't really care to get into an objectivist vs. subjectivist debate, because I don't like any extreme positions like that.

I just have a different philosophy. Instead of trying to offset one problem by adding a component with an opposite problem, I'd much prefer to neutralize the initial problem in the first place. I desire an accurate system that has a chance to reproduce exactly was was recorded. True, a lot of recordings really suck, and the better the resolution of the system, the more this is true. But recording can get better. Modern CDs can be outstanding.

How many times have you heard what you thought was an improvement because it was more "exciting" or "lively", only to tire of it after extended listening, choosing to go back to the more "boring" or neutral sound? Ears are fickle.
 
I think we have a misunderstanding here. It started from my post, about using one or the other insulating pad under the chip.

Now, this chip is mounted on 3/4" thick 2" x 8" aluminum bar. I stated that I prefer the sound of aluminum oxide pad over the silpad. I cannnot imagine that using aluminum oxide pad is creating more vibration in a chip than using silpads. I can only imagine that the resonant frequency might be altered by one or the other type of pads, but never eliminated completely.

According to what you try to suggest, I purposly mount the components so they can vibrate to create so called "euphonic" sound. This is nonsense.

I simply noticed, that no matter how well the components are mounted, or how well the chassis is built, it will still show complex vibrational modes, which can be altered in one way or another.

You can take your most heavily built Krell amp (or whatever else you prefer to choose) and still alter its sound by means of different supporting platform or material under the feet. There is no way you can avoided that. Now, by proper tuning and allowing one or the other type of resonances, you can change the sound of that unit. It is still accurate and neutral (because its made by Krell;)), yet the sound can be altered more or less to your prefference.

Was this unit designed to be "euphonicaly" colored? I guess not, but in certain setups it may seem to be like that and in other setups, it can be sounding overdamped and "neutral". Please note that I'm still talking about the same amp, just that the sound can be changed in one way or another.

I would never allow myself to deliberatly design a piece of equipment to have some parts loose or vibrating purposely. I just noticed that whatever you do, you still have to deal with the issues of resonances. Now, it is your preference and personal taste, how you to go about them;)

I particularly like this statement, taken from 47Labs site:

Another radical approach we took, which is often neglected or paid least attention to, is the control of mechanical resonance. We do not automatically consider vibrations as negative. After all, vibrations and electrical current come from the same energy. Instead of damping and trying to kill the vibrations, which instantly causes delays and modulations in the flow of current, we release them smoothly and quickly by the design of a compact and rigid chassis construction and control the resonance with the choice of materials. So, there is no damping materials or suspensions in our products at all.
 
pooge said:


How many times have you heard what you thought was an improvement because it was more "exciting" or "lively", only to tire of it after extended listening, choosing to go back to the more "boring" or neutral sound? Ears are fickle.

Quite a few, and indeed my temptation was to go back to more boring and neutral sound, but I never did it. I always managed to find a better alternative. This is also a never ending search and a constant quest for that ultimate "holy bandaids".;)
 
Hi,

I hope this question I am asking is not too off topic of the thread.
What is the best way to isolate the mounting screws from the transistors or TO-220 diodes and heatsink. For example the way Peter Daniel's discrete rectifier uses one screw to mount two TO-220 diodes sandwiches or sharing a heatsink. Plastic screws?

Any tips?

Regards,
Chris
 
After all, vibrations and electrical current come from the same energy. Instead of damping and trying to kill the vibrations, which instantly causes delays and modulations in the flow of current, we release them smoothly and quickly by the design of a compact and rigid chassis construction and control the resonance with the choice of materials. So, there is no damping materials or suspensions in our products at all.

This makes absolutely no sense. Vibrations and current do not come from the same energy. How in the hell does killing vibrations cause delays and modulations in the flow of current? The opposite would be more likely. Where are the vibrations "released" to? How are the resonances "controlled"? Sounds like new age marketing crap to me.
 
pooge said:


This makes absolutely no sense. Vibrations and current do not come from the same energy. How in the hell does killing vibrations cause delays and modulations in the flow of current? The opposite would be more likely. Where are the vibrations "released" to? How are the resonances "controlled"? Sounds like new age marketing crap to me.


That's not my statement, but I just happen to like it.

Whould you like to comment, what kind of different energies they do come from (vibrations and current)?
 
millwood said:



but you did say that less damping results in airy sound. Maybe you would like to comment on exactly how that is done?

It is still a guess, but this is what I think.

Aluminum oxide pad is made of ceramic like material, which is very hard and brittle. Silpad is more soft in comparison.

When insulating pad is used, any vibrations that occur in aluminum chassis are transfered through the pad to the chip. Since both pads have different physical properties, they also change the amount and type of resonances passing to the chip. I would imagine that hard and brittle material can introduce more airy sound, while something that is softer, more laid back and toned down character. What do you think?
 
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Peter Daniel said:

I would imagine... What do you think?

I think that the mechanical vibration energy is too weak to change the position of electrons and protons at rest (or moving at certain speed) inside a conductor (and semi-conductor). This means that only the electrical energy could be believed as the inertia force for the electrons and protons.

JH
 
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Peter Daniel said:
Since both pads have different physical properties, they also change the amount and type of resonances passing to the chip.


Peter Daniel said:
I would imagine that hard and brittle material can introduce more airy sound, while something that is softer, more laid back and toned down character. What do you think?

I am not sure. Foundamentally, that's the question that pooge asked and I have no answer for it. I have not personally read any impact that mechanical vibrations may have on electric characteristics of a semiconductor device. I do know that stress can generate noise but that is too low to be noticed here. Plus, the whole die is mounted on the base plate so even if there is vibration of the whole plate, there is be limited stress on the die itself.
 
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Peter, I respect you as much as anybody else on this forum. and I think it is an understatement to say that I have learnt a lot from you all. and I am sure that will remain ture for the rest of my life.

But that doesn't mean that I wouldn't ask tough questions, and that doesn't mean that I can be pushed aside, qualification or otherewise.

We are here because we love DIY audio, and we are eager to pick up new things from each other. If there is a qualification, that's it. Not your background in electronics (or not), or my background in banking, whatever.
 
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