To stack or not to stack?

Er, just wondering - is it just the cleanness of the supply that's gonna vary or is it the 50Hz frequency that may be wander. I only ask cos if the frequency varies, this is gonna have consequences for those of us with record decks running with AC motors. It also doesn't sound like the kinda thing that the various mains conditioning wonder products/snake oil products (delete as appropriate) is gonna sort out.

PS. I plead complete and utter ignorance in these matters and seek guidance from someone wiser

 

Hmm, I wonder how thermistors work then? And thermocouples for that matter

 

We were talking about hi-fi components, were we not?

 

But they still move, don't they? I mean, they don't all stop dead or slow down to a crawl. And they would all move at the same rate at a given temperature, wouldn't they? If so, why should hi-fi sound change with different temperature? I don't believe it, but I'm open to be educated.

And the bit about chemicals is a generalisations that doesn't hold true universally, e.g., any sort of biochemical system. Try heating that to 100°C and see how your reaction goes.

 

yep we were Tones, but i think what they are getting at is that there is a direct relationship between a conductors temp and its resistance or lack of. In some circuit like Iriaa where signal path resistance is fairly crucial then this would affact the sound until it reaches optimal temp, whatever that may be.

 

Although I'm now considering keeping my system apart when i move rooms and update my system next month, i'm pretty unimpressed with alot of the racks available. I'm not really into metal racks, or spending alot of money on a cabinet, infact I was thinking of giving it a bit of an industrial look and making a rack out of bricks and bits of plywood and siting it somewhere unobtrusive. so 2 questions.....

What distance do you need realistically between parts?will a few inches do it? (I don't want a towerblock!)
And what are the downsides (i'm sure there must be some) of bricks and ply?! (i have a turntable)

HM

 

Got mine arranged like this:

http://forum.hifichoice.co.uk/viewtopic.php?p=62692#62692

Hmmm, damn T-Mobile website! . Well I have my two top shelves of my Atacama rack with two components on each (oh almost forgot about the PS2 on the top). Link should work now.

 

Dean, img links which aren't ovbiously images (ie, don't have a recognized extention) won't show up properly. Better to just post the URL in those cases.

Michael.

 

Good, I wasn't actually aware of any thermocouples in my hi-fi (I wouldn't know a thermistor if I fell over one). It's well established that electrical resistance changes with temperature. But don't you see the logical jump we're implicitly being invited to make? The extrapolation moves from "change in resistance with temperature" (totally correct) to "change in sound quality with temperature" (totally baseless). Why should audio signals be affected by temperature? After all all those little electrons are equally affected, so, if they're all equally affected, the chances are that the result will be the same. How can you say so positively that

"this would affact the sound until it reaches optimal temp"?

This is only an unsubstantiated expression of belief.

Moreover, we're generally not talking enormous differences in temperature between hot and cold in, say, a CD player. Such devices generally live in comfy living rooms at ambient temperature. They generate some heat in operation, but we're not talking mammoth currents, so we're talking how much of a temperature increase? 20-30 deg C? That's going to have an negligible effect on resistance. So, why should the sound change? OK, I know, Tone and others have heard it, but doubting Thomas here never has, and until he has heard this difference with his own little ears, poor though they are, he will not believe.

 

Ive noticed it with my kit for a long time Tone, im not distubting what you say in regard of your own kit/ears.
I notice it moreso with my valve phono pre, infact that is very noticeable.
Audio signal are electrons being acted upon by components with the cdp amp or whatever, so if the value of a component can change with temp then it stands to reason the effect on electrons will also change, as to wether this is infact a noticeable change is subjective.
I guess it is down to the individual and if they actualy can hear a change and if so do they worry about it.............

 

Tones, quite a few amplifier output stages have 'temp sensing f.e.t.s'' which then bias the output current accordingly to the bigger more rugged (not in the case of the AVI's though ) output channel devices, much in the same way an a coolant temp sensor effects the fueling of (along with thottle postion/crank angle/camshaft timing/air/temp/maifold vacum/O2 sensors) do.
Some delicate electronics have thermo sistors if you like placed close to the cmos sections (which draw more current) that dictate coolong fan operation (smart ones use seperate psu's again),
the heat sinks on the some of the wadia's are 40MM in diameter and are 55mm tall and are solid stainless bolted to the top plate, and contact direct on the dsp chips for what they do, they take a lot of current and generate a fair amount of heat.
any way stacking I try and keep the source equipment away from any big transformers, unless a few sheets of ERS or Tin foil are used. Wm

 

Many transistor output stages use temperature feedback to ensure that the output transistors aren't destroyed. The voltage bias is reduced as the output devices warm up, you arrange this by thermally coupling the bias generating transistor to the output transistors.

There's no apparent reason why the amp might sound better hot, the aim is to make its operating conditions constant with temperature changes.

It's odd that nobody ever has a system that sounds best cold and deteriorates as it warms, which would appear equally possible.

Paul

 

Maybe Im becoming less and less audiophile......

Id much rather be in some shops (or practically anywhere) rather than looking at the wave form of pieces of mains flex on an oscilloscope!!

PS Tones -
apart from my valve stuff/class A amps etc, hifi sounds the same to me aswell when fresh on as when its been on a while. For example my transport sounds the same fresh on as when its been off. My old DAC was the same etc

IMVHO I dont think youve got cloth ears, I just dont think you're afraid to say when a difference is negligable or non existant to your ears. Keep up the honesty matey, its refreshing in this bullshit-lined industry..

 

Tones, I'm gunna try a piece of reverse physcology here, how about people 'won't hear' a difference because they firmly believe from the start it's all bollox, in the same vien your suggesting they *do* hear a difference becasue they believe they will, or because they *don't want to* Tone

 

If you've fairly revealing and decent kit then put every box on a separate shelf. Also, divide your boxes into two categories: brawn and brain

Brawn components are CD players, turntables and preamps.

Brain components are power amps, power supplies and phono stages.

Brawn and brain should be kept at least four inches apart.

Ideally the preamp should be on a top shelf, turntables should be on separate wallshelves and CD players should enjoy a little more isolation than the other boxes in order to maintain hierarchical balance through the whole system.

Try it and see. In some cases it will cost you nothing and yet the musical benefits will be obvious.

 

I agree completely, Tone, in fact, on a few other threads, I've said this very thing. I acknowledge that I may not hear minor differences because I don't want to hear them, so anything that doesn't make a major, obvious difference is rejected.

Perhaps I've overcompensated since the time I caught myself wanting to hear a difference - you know, the "I've just spent £XXX on this and I want to hear an improvement" feeling. And if you want to hear a difference, you may hear one. I suspect that many of you who do hear small differences hear them because you are expecting them, perhaps subsconsciously.

Ultimately, this is all a very subjective business, since the sound system comprises not just our equipment but also the ears and the brain that analyses the sound waves received by the ears. And, as we are all individuals, the perception and interpretation of those sound waves will be different in each and every case. Thus, there is no "right" and "wrong" point of view, only what is right for the individual. I completely respect your right to hear things that I don't, the way I respect John Watson's right to hear new sound miracles every time he goes up another phase of Mana. I hope that these folk will also respect my right not to hear these differences. I know you do, and I think the rest of the forum does - which is what makes it such a nice Forum to visit and exchange views (Michael, take another bow, please).

 

Fighting my way through the packed pre-Christmas shops is NOT my idea of fun, especially when I'm going to be looking for things like some table mats and an umbrella for my mum...

Looking at waveforms on a 'scope is not my idea of fun either you'll be pleased to hear , but given all the discussion I would be interested to see what is going on. Not sure I'm going to have time now though TBH.

 

I think I understand why some advocate ABX testing.

In this the listeners are told there are 2 systems that can be selected by a switch. They are different and the listener objective is to try to look for the audible difference. They could even play A and B again and again until listener is satisfied.

Then a random selection is made and listener is to guess X is either A or B. If there is an obvious difference between A & B listener should be able to identify it consistently.

Sounds simple enough to organise if you have such a switch box.

 

Tones, I have just come across something that you may find interesting.

Apparently electrolytic capacitors rely on ionic conduction to work. This ionic conduction occurs in the electrolyte.
Ionic conduction is known to be rather temperature dependant.
Supposedly many audio electrolytic capacitors sound and measure their best at a respectably high temperature such as 40 degrees centigrade.

This leads me to believe that the temperature of a capacitor will have at least a small effect on circuit that they are used in.

Is it not possible then that temperature can have an effect on the sound quality? Whether or not we can hear this difference is another matter and may rely heavily on a large amount or variables.

 

not enough evidence for Tones