Vibration, isolation and electronics...

[Orb]

Well my post is there to also state one cannot take the view it does not affect sound.
We know it can be audible as seen with the CJ preamp, but this then becomes a question of threshold and that solid state will be less than that measured in the CJ.
Anything else I feel is leaning towards speculation (as to its real world effect) and theory debate
This applicable to both the following camps of view; that it has a noticable effect in solid state gear, or it has no audible effect and is not an issue for solid state.

Thanks
Orb

 

[fas42]

I might just add that there are numerous subtleties that affect SQ apart from vibration, and an unfortunate fact of audio life is that the better your system is, the more the slightest deviation of some aspect from optimum of the setup will stand out like a sore thumb. My poor friend was getting great sound until he did a silly thing: went to the kitchen and turned on an electric kettle to do a cup of tea for us. Bang! The sound quality fell off the cliff compared to what he had a moment ago, in spite of having isolation transformers and other fiddling to counter such interactions. It's a hard life for the perfectionists in audio ...

Frank

 

[Johnny Vinyl]

It's a hard life for the perfectionists in audio ...

Frank

Thank God I'm not one of them.

 

[terryj]

I might just add that there are numerous subtleties that affect SQ apart from vibration, and an unfortunate fact of audio life is that the better your system is, the more the slightest deviation of some aspect from optimum of the setup will stand out like a sore thumb. My poor friend was getting great sound until he did a silly thing: went to the kitchen and turned on an electric kettle to do a cup of tea for us. Bang! The sound quality fell off the cliff compared to what he had a moment ago, in spite of having isolation transformers and other fiddling to counter such interactions. It's a hard life for the perfectionists in audio ...

Frank

that's one way to view it i guess.

The other way is to get a proper, well engineered system that does not 'fall off a cliff' when someone switches on a kettle.

Perfectionism or incompetence?

And, one may ask, what good (exactly) were these isolation transformers and other fiddling to counter such interactions.

Did he ask for his money back? Had he previously raved about the improvements they brought and how every system needs them if it is to be called top notch?

If the sound became that bad, I bet even his wife heard it.

 

[ack]

I'd like to see the signal leaving the preamp before and after the isolation. I'll go out on a limb and suggest that there is no change. The chassis vibration differences are interesting, but the question remains does isolation contribute to fidelity?

Precisely. The spectral decay simply shows how a box or any other *structure* vibrates before and after - big deal, we all know they all vibrate, from chassis to equipment stands to turntables to walls and floors. As you say, it's the electrical signal that eventually matters. I'd like to see proof of that as well.

 

[microstrip]

I might just add that there are numerous subtleties that affect SQ apart from vibration, and an unfortunate fact of audio life is that the better your system is, the more the slightest deviation of some aspect from optimum of the setup will stand out like a sore thumb. My poor friend was getting great sound until he did a silly thing: went to the kitchen and turned on an electric kettle to do a cup of tea for us. Bang! The sound quality fell off the cliff compared to what he had a moment ago, in spite of having isolation transformers and other fiddling to counter such interactions. It's a hard life for the perfectionists in audio ...

Frank

Well, sometimes this electric cattle effect can be easily explained. Most of the time these water boilers use high power resistive heaters to boil the water - e.g. 1600W is an usual value. This extra load can lower the voltage of your mains to a point it can be audible, and no filters or insulation transformers will help about this.
This effect can be dramatic with tube equipment, as usually the filaments of the power tubes are not regulated and cathode emission is very dependent on heater voltage.

 

[microstrip]

Tim,

If you have usd 160.00 and plenty of time to spend you can buy this book- "Vibration Analysis for Electronic Equipment" (I only read the index, some sample parts and some reviews).Although the author concern is mainly with reliability (military are more serious than audiophiles), the vibrational analysis of PCBs and circuit boards seems to be very extensive and Chap 10 is entitled Acoustic Noise Effects on Electronics. A review of the book noted that "This book is not suitable for a textbook. But it can be a useful reference in the design of electrical and electronic equipment".

You can look inside at
http://www.amazon.co.uk/Vibration-Analysis-Electronic-Equipment-Steinberg/dp/047137685X/ref=sr_1_1?ie=UTF8&qid=1309454770&sr=8-1

 

[RBFC]

Tim,

If you have usd 160.00 and plenty of time to spend you can buy this book- "Vibration Analysis for Electronic Equipment" (I only read the index, some sample parts and some reviews).Although the author concern is mainly with reliability (military are more serious than audiophiles), the vibrational analysis of PCBs and circuit boards seems to be very extensive and Chap 10 is entitled Acoustic Noise Effects on Electronics. A review of the book noted that "This book is not suitable for a textbook. But it can be a useful reference in the design of electrical and electronic equipment".

You can look inside at

http://www.amazon.com/Vibration-Analysis-Electronic-Equipment-Steinberg/dp/047137685X

As a moderator, my first glance at your link raised my eyebrows!

Lee

 

[JasonI]

Well my post is there to also state one cannot take the view it does not affect sound.
We know it can be audible as seen with the CJ preamp, but this then becomes a question of threshold and that solid state will be less than that measured in the CJ.
Anything else I feel is leaning towards speculation (as to its real world effect) and theory debate
This applicable to both the following camps of view; that it has a noticable effect in solid state gear, or it has no audible effect and is not an issue for solid state.

Thanks
Orb

Like one can't deny the existence of subquarkian strings or God, one can not deny the existence of chassis vibration's negative affect on sound quality. Some of this has to do with placebo and two definitions of low hanging fruit. The first definition can be provided with an example.

We all know that treating the listening room is probably the number two factor for good sound. The number one factor being that a system exists in the first place. The trouble with room treatments is that they are resource intensive, consuming both time and money, and the impact on decor is not always acceptable. This is the first definition of low hanging fruit: significant gains by treating well known phenomenon at a considerable cost.

The second definition is more about low cost and ease of implementation. It's far easier to spend $40 on a couple of pairs of simply installed rubber feet for a preamp than to spend thousands of dollars and several hours treating a room. This option, though easier, leads to questionable gains.

From what I gather, marketers raise prices on their products to distract consumers from asking these questions. If the price is high, there must be some valid reason for it and it must be good. Or in the case of the QPods, a straw man chassis vibration graph is provided with no indication of signal quality improvement. Placebo can be as powerful and have as much impact on perception as room treatments.

In my opinion, one is better off treating the issues that are not controversial; the incontrovertable undeniable facts, the known knowns, the low hanging fruit. If you're installing rubber feet to reduce chassis vibration in effort to squeeze the last iota of sound quality out of a system without first having taken care of the truely deliterious affects brought on by a poor listening room, poor speaker selection, and poor speaker placement I'd say you were wasting your time, money and effort.

This response is meant for the proverbial audience and not any one in particular, Orb.

 

[JasonI]

as a moderator, my first glance at your link raised my eyebrows!

Lee

lol!

 

[Orb]

Like one can't deny the existence of subquarkian strings or God, one can not deny the existence of chassis vibration's negative affect on sound quality......

Indeed, as one also has to accept that their points on God is speculation and various theory, most of the discussion for/against certain aspects of vibration and microphonics is speculation while other aspects are facts and theory, but as it includes both speculation and theory it will not satisfy most who fall either side of the fence.

Thanks
Orb

 

[FrantzM]

Hi

Are there studies that show the effect of mechanical vibrations on SS components? Tubes exhibits microphony to various degree: from subtle to obvious, plates can sing along with the music .. Not a bad tubes necessarily.
I am yet to understand the effect of vibrations on cable .. on connectors? maybe if it loose but a cable? .. I would like to see those studies if they exist.
Meanwhile my fellow audiophiles find best to place their monoblocks close to their speaker, be it tubes or SS...
Audiophile think eveything can affect the sound, including the moon... If you think that far fetched, some think that this

can work wonder for room acoustics and vibration control (from shunmook who sells, successfully I must add, various "vibration control devices".

 

[microstrip]

As a moderator, my first glance at your link raised my eyebrows!

Lee

UF! Saved from the people who write in green by the British branch!

 

[JasonI]

Indeed, as one also has to accept that their points on God is speculation and various theory, most of the discussion for/against certain aspects of vibration and microphonics is speculation while other aspects are facts and theory, but as it includes both speculation and theory it will not satisfy most who fall either side of the fence.

Thanks
Orb

I think that if the QPods manufacturer has equipment sophisticated enough to measure and graph the vibrations of a preamp chassis, they should also have equipment sophisticated enough to measure the signal coming out of that chassis. That would end or at least clarify some of the speculation, I think.

 

[audioguy]

I think that if the QPods manufacturer has equipment sophisticated enough to measure and graph the vibrations of a preamp chassis, they should also have equipment sophisticated enough to measure the signal coming out of that chassis. That would end or at least clarify some of the speculation, I think.

Even if the measurements show some vibration, that does not imply that it is audible, but only that it exists.

Let' see: 4 stands, 8 holders, 32 mpingo discs AND a partridge in a pear tree !!

I was actually in a demo at some CES long ago where that configuration was "demonstrated" and the presenter convinced EVERYONE (but me) in the room that the before and after difference was both audible and profound. It was like he hypnotized everyone in the room. Quite bizarre actually.

 

[Phelonious Ponk]

I think that if the QPods manufacturer has equipment sophisticated enough to measure and graph the vibrations of a preamp chassis, they should also have equipment sophisticated enough to measure the signal coming out of that chassis. That would end or at least clarify some of the speculation, I think.

I'm sure they do have the equipment and I suspect they measured the effects on the signal. That they didn't choose to share them is telling. But I'm not saying that they are deliberately deceiving anyone. My guess is they believe it has an unmeasurable, but audible effect, just like their customers do. Or at least I'm willing to give them that benefit of the doubt.

This is no different than the Japanese hifi manufacturers of the 70s and 80s who kept driving THD to lower and lower levels, using it as a marketing tool long after it ceased to have an audible effect. It's no different than the jitter reduction of today. Ever lower numbers, ever higher prices, all sustained by placebo. Amir is trained to hear the artifacts, but he has to put on his Stax and turn up the volume to spot them. Audiophiles with more highly developed sense of drama can play a $5k DAC in an untreated room and hear the soundstage open like a flower...

Tim

 

[fas42]

I am yet to understand the effect of vibrations on cable .. on connectors?

There's at least one simple mechanical way of explaining effects: conductors next to each, as in a cable, or actually contacting in a rough way, as is the case for most connections, vibrate in symphathy with the air or room surfaces movement; the conductors adjacent to each other form an obvious or subtle capacitor element, so the vibrating surfaces then can easily end up looking like a variable capacitor, changing its value at the rate of the vibration. Which the audio circuitry sees as being part of the system. A subtle, perhaps very subtle, effect but enough for a better quality system to make very audible ...

Frank

 

[fas42]

The other way is to get a proper, well engineered system that does not 'fall off a cliff' when someone switches on a kettle.

Perfectionism or incompetence?

And, one may ask, what good (exactly) were these isolation transformers and other fiddling to counter such interactions.

Did he ask for his money back? Had he previously raved about the improvements they brought and how every system needs them if it is to be called top notch?

If the sound became that bad, I bet even his wife heard it.

The loss of quality was relative: the tweaking by the transformers and cables stuff had pushed the quality up high enough that even the loss with the kettle going was not as much as would have been the case if you removed all the work done in this area. In other words the changes were helping the sound a great deal but still weren't enough to counter the effect of the voltage disturbance by the kettle.

The equipment is pretty decent: the amp is a current, completely unmodified Naim Nait 5i, which I just found out TAS was rather impressed by, the CD player an older, very heavily modified Quad unit: lots of work to smarten up the behaviour of the power supplies in it, these have made big improvements to the sound.

Frank

 

[terryj]

There's at least one simple mechanical way of explaining effects: conductors next to each, as in a cable, or actually contacting in a rough way, as is the case for most connections, vibrate in symphathy with the air or room surfaces movement; the conductors adjacent to each other form an obvious or subtle capacitor element, so the vibrating surfaces then can easily end up looking like a variable capacitor, changing its value at the rate of the vibration. Which the audio circuitry sees as being part of the system. A subtle, perhaps very subtle, effect but enough for a better quality system to make very audible ...

Frank

It seems to me that hi end audio is most susceptible to the phenomenon of taking a bit of data from science, which may or may not be applicable, and using it to back up whatever theory is needed at the time.

The more obscure and questionable the 'observation' being defended or explained, the more prevalent this behaviiour becomes.

IS there some other area that does this as much or more??? Creationism?

Ok, the above is a theory. Fine. Let's test that theory yeah?

That does NOT men we now take the time to set up the experiment, buy the gear, take the time, run measurements and analyse the data. That would be foolish, and I am sure it would not be scientific to do so. (hey, not that science plays much role in audio)

No, we at least make some preliminary calculations to see if the 'maths' validate the theory at first glance.

So, is there an engineer amongst us who can give us some back of the envelope calculations to tell us what magnitude this theory predicts?

Find a FULL formula for calculating capacitance (there are a lot of readers digest formulas around for these type of things, I remember when I first saw the full formula for inductance for example...it included ALL parameters that affect the inductance).

Now plug in the 'figures' and see the results.

What is the estimated physical movement of the cable due to air particles??? How many angstrom units are we seriously talking here??

The same for floor born vibrations?

Frank what is YOUR real world estimate of the effects you are positing?

You DID make them to see if your theory held water?

Is there someone who can make (or get) the estimated value of this effect?

 

[terryj]

hi frank, you must be doing your early morning browsing at the same time as me! You replied as I typed an earlier post.

good morning to you, how's the weather there?

Obviously I cannot say that 'it didn't happen'....I guess it could have. Still, it seems to me to be a poor system if it did so. Good basic engineering is not hard to find nor is it expensive.

Add on 'tweaks' on the other hand tend to be expensive in comparison, especially if it is not needed when properly done.

WHY did I raise my eyebrows when people mentioned these things??

Well, I live out in the country, and the power supply at times can be questionable. Probably worsening it is that I live towards the end of the spur (if that makes sense), guess there are not too may houses further along. (I don't know much about how the infrastructure woks, that could be baloney and no such spur exists, ie everything could be interconnected for redundancy sake for example)

Anyway, we are not on town water, so our only water supply is a (proper) well, made over 150 years ago. Amazing, they managed to find a reliable water supply all that time ago, without modern technology. AND were so sure of themselves they dug a well about thirty metres deep to get it. How is that for confidence? "keep digging boys, it IS down there".

The point? Well, it obviously needs a pump to get the water out, a big old cast iron thing it was. (now dead, replaced with a modern one).

I'd be listening to music, and the pump would come on. HOW would I know that? Well, if I had my eyes shut or the lights off I wouldn't.

Else I could tell because all the lights would dim for a few seconds.

Not a skeric of audibility.

So there ya go, I reckon it would be easier to just buy well engineered products in the first place.