"audiophile" components in pedals?

Started by slowpogo, June 28, 2019, 12:50:34 AM

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Digital Larry

#20
Quote from: Rob Strand on June 28, 2019, 11:07:10 PM
I believe dielectric losses have a significant hysteresis component.   Hysteresis itself isn't a non-linear process it's a loss process whereas D-E curves are clearly non-linear.   Unless you are building A/D's or insanely high Q filters the dielectric loss isn't a significant issue for *audio signal* as such.

I'm not as much of an analog expert as I pretend to be.  Much of what I complain about is simply people's difficulty with the experimental method and creating a compelling argument.  If he'd just linked to this article I would have said, "Oh, OK.  THAT I can believe".

https://en.wikipedia.org/wiki/Dielectric_absorption

But the approach of "I'm going to crank signals way over what you'd normally encounter to make the effect easier to see" doesn't prove that the issue is problematic under typical design/use conditions.  These types of arguments send my skepticism into high gear.

I can make transistors distort the crud out of any audio signal you like by cranking the level or gain or whatever.  This doesn't change the fact that ~100% of all REPRODUCED sounds you hear have gone through hundreds of transistors by the time you hear them. 
Digital Larry
Want to quickly design your own effects patches for the Spin FV-1 DSP chip?
https://github.com/HolyCityAudio/SpinCAD-Designer

Rob Strand

QuoteMuch of what I complain about is simply people's difficulty with the experimental method and creating a compelling argument.  If he'd just linked to this article I would have said, "Oh, OK.  THAT I can believe".
Pure mathematics in the only place I know where you start with a known truth and have a careful succession of true statements.   That type of thing is totally outside of what most people do.  The majority of stuff boils downs to opinions and word games.   If your wife's friend tells her something no logical argument can change the truth of that  :icon_mrgreen:.

With equipment like this you can actually see how the capacitance and losses change with frequency,

Small capacitance meters, even the purpose built ones, usually don't produce the same numbers as these mighty beasts.

QuoteThese types of arguments send my skepticism into high gear.
I'm the same.   Marketing in the hifi industry relies on propagating black magic.  Measurements alone don't mean much when it comes to human perception.   There's zillions of man hours work hiding behind the perception models in mp3.   How we perceive sounds is very complex.  The mp3 stuff is largely linear.   Perception of distortions is even more obscure.
Send:     . .- .-. - .... / - --- / --. --- .-. -
According to the water analogy of electricity, transistor leakage is caused by holes.

Mark Hammer

Perception is indeed complex.  And a lot of it depends on context: what is perceptible in one context is or becomes imperceptible in another.

Perfect case in point is hiss and masking.  In the context of a robust signal that is coherent enough to command our attention, we don't "hear" (notice) hiss.  Take that signal away and the very same amplitude of hiss is annoying.

Since all the brouhaha over components ultimately boils down to whether it impacts on the aesthetic/hedonic qualities of the resulting sound in a consistent replicable manner, and since that in turn can vary with context, it complicates things.  And that's true even when the signal only runs through two transistors!  :icon_wink:

Rob Strand

QuotePerfect case in point is hiss and masking.  In the context of a robust signal that is coherent enough to command our attention, we don't "hear" (notice) hiss.  Take that signal away and the very same amplitude of hiss is annoying.
To a certain degree that argument applies to distortion.  If you have high-order harmonics (read that as high frequency) they are separated further from the main signal and they get masked less.  So by the same argument low-order order harmonics are kinder to the ear.   The angry high-order harmonics is why we often use low-pass filters in the fuzz pedals (and why the hf roll-off of guitar speakers is an important part of the sound).
Send:     . .- .-. - .... / - --- / --. --- .-. -
According to the water analogy of electricity, transistor leakage is caused by holes.

Rob Strand

Send:     . .- .-. - .... / - --- / --. --- .-. -
According to the water analogy of electricity, transistor leakage is caused by holes.

bluebunny

Quote from: bool on June 29, 2019, 06:45:55 AM
With "hifi" parts, you usually "listen with your eyes".

With "hifi" parts, you usually "listen with your wallet".
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Ohm's Law - much like Coles Law, but with less cabbage...

Gus

If you read about or measure caps and resistors you might notice the distortion often get worse with voltage differences across the devices.

Effects work at a lower voltage.

You might hear more noise with thick film SMD and CC resistors depending on the circuit.

Read about Class1, Class 2 and Class 3 ceramic caps.
I sometime use ceramics that are microphonic and subject to value change with voltage from plate to plate in fuzzes.