John Curl's Blowtorch preamplifier part II

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You know, there have been pages and pages about this cap distortion bull **** and DA stuff and no clarity on the issue has emerged.

So fcuk it - I'm just going to go for direct coupling and be done with it.

As for RIAA - do it in DSP or move over to CD ( that'll be high res downloads for you Richard!)

Down with caps! Period!
 
No doubt, distortion is due to the dielectric used, in unipolar capacitors like electrolytic capacitors is a function of voltage polarity and amplitude as well, but it again leads to dielectric properties.
Still trying to understand the meaning of all the previous controversy about DA ;-)
Some people having a different definition of DAs in their subconscious ? I mean, some took the poor linear model to define the physical phenomena and want an other acronym for what is not modeled that we are seeing in the measurements?
 
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A remarkable claim was made that DA is the cause of nonlinearity.
What else ?

When evidence was sought (and that took a lot of pressing), it was not forthcoming. So... draw your own conclusion.
So, please, give-us your own definition of DA to help me. I'm not very good for drawing conclusions without antithesis.
 
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Just a note on measuring distortion. Today the method of choice is a DSP based system that uses FFT. This allows fairly precise identification of the level of the fundamentals and each harmonic.

The prior generation of test equipment used a notch filter to tune out the fundamental. The Noise and Distortion was just often read on a meter. Now to get a % reading the fundamental was adjusted to a reference level before the notch filter. Now what is interesting is that even with linear distortion that reduced the fundamental the harmonics would read higher!

So when reading older papers the method of measurement comes into play.
 
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Let me try again.

DA is modeled with multiple Rs and Cs and that model cannot lead to or explain nonlinearity.

But we don't know whether this model is all there is to DA, do we? It explains charge/recover cycles, but that's all it does because that's all we ask of it (the model).

We seem to agree that nonlinearity is impacted by DC bias on a cap. We know that DA, in a situation of changing DC bias, impacts the value of DC bias with time. So it appears that there might be a basis for a causal link between DA and nonlinearity. Bateman found 'a' link but we don't know it is causal.

Where in this reasoning did I go wrong?

Jan
 
Richard made comment of 'silence between notes' with low DA caps.
Can particular cap dielectrics a exhibit a Barkhausen effect like noise ?.

Dan.

No references anywhere on that. In fact no mechanism I can think of for that oft repeated "silence between notes" too close to memory and echos for me frankly. You see how this DA thing got carried away.
 
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