I hope we are not going to revive first cycle distortion. Let's leave it at opinion.
Checked and is still available new, and also good offerings in used, according to bookfinder.com.
Two things
1 sounds bad
2 there are delayed components - "artifacts" oh! not supposed to use that word
so what do we call it? what's the adjective/noun going to be?
Different timbre.
Like speaking in front of a wall and in front of a wall covered by a curtain causes different timbres since curtain absorbs highs. Similarly, capacitor with DA will slightly attenuate highs when it passes the signal between 2 nodes with linear constant resistances.
FrankWW, what I intend to say is the following.
Diffraction around edges, ridges etc. creates independant wave fronts that may combine (di)(con)structively with the driver as the primary sound source. This creates an interference pattern that flip-flops when taking measurements from different angles. In other words, the FR can show significant shifts even at distances well within normal head movements. Phase shifts around as well.
That sounds lousy, pin points the locations of the speakers and destroys stereo imaging, but it is not distortion. It does not show up in measurements as such, and I also can't see what mechanism could cause distortion. Adding two sinoids of the same frequency will produce another sinoid with the same period, even if the two sinoids are different in phase or amplitude. That's what's happening in my eyes, so no distortion products.
Diffraction around edges, ridges etc. creates independant wave fronts that may combine (di)(con)structively with the driver as the primary sound source. This creates an interference pattern that flip-flops when taking measurements from different angles. In other words, the FR can show significant shifts even at distances well within normal head movements. Phase shifts around as well.
That sounds lousy, pin points the locations of the speakers and destroys stereo imaging, but it is not distortion. It does not show up in measurements as such, and I also can't see what mechanism could cause distortion. Adding two sinoids of the same frequency will produce another sinoid with the same period, even if the two sinoids are different in phase or amplitude. That's what's happening in my eyes, so no distortion products.
The use of imprecise language makes a technical discussion very difficult.
If you do a test on a "passive" (linear?) part, like a capacitor, and that test produces a second harmonic AND the listener description of the part is the same as hearing a tone or music with added second harmonic.... ??? call it what you want -- I call it distortion. The cause of it is dielectric absorption ..... lower the DA and the same test shows no or much reduced 2nd harmonic. And, again, listeners say it sounds better. What's the problem here?
The only other thing new is that the test did not use a symetrical waveform (sinewave) and was more like transient music signals.... which lead to greater peak levels of distortion (than sine wave analysis) which pointed clearly to DA. Which is what the test was designed to show better than sine wave testing.
As a side note: polar caps were used in ss amps at first and thier model does show a weak diode effect. Contacts and joints of dissimilar metals can also have weak diode effects. But now we design without bipolars and with servo's etc - direct couple. So this is mostly of historical significance.... through listening, insights, and new test methods has lead to better component understanding and better sounding equipment.
Last edited:
The problem is DA is modeled with only a network of ideal R's and C's this can not produce second harmonic distortion. DA and voltage coefficent of capacitance are not the same thing and observing a corellation with one particular dielectric does not make it a general rule.
Dick no offence intended if you're used to a different definition of DA, fine, it's just a misunderstanding.
Demian - Non-minimum phase is impossible with only ideal R's and C's
yes thats true. The model you have seen is a simplified model of dielectric behavior - obviously. And, S.W. is correct also, I am sure. And, there is an incomplete explaination of how the DA effect manifests itself audibly. The dielectrics have affects lumped in with DA such that the end result is the rank ordering by DA works for the listener/designer. And, there is some missing info which I have that are not in my notes from the DSP^x talk. The observed results as reported are still useful without getting further into it. Most people - certainly not the place in this blog - are not interested in the gory intellectual details. If you do the test and reread what I did you can figure it out. A more thorough examination could be of some use, i suppose, for completness and full discovery and disclosure..... dont know of any practicle advantage to doing so. Simplify - works for most people.
Does the Volt Coef rank order the same as DA? If so, then maybe THAT is the more correct property to be focused on for choosing caps in audio?
Voltage coeff is part of it, for sure. Especially with ceramics. But the non sinewave test shows higher levels of second for various films as well and listening tests show a direct correlation with DA. Its just more sensitive to this particular issue. What ever it is... if not DA. I would conceed that maybe we need a more complete model. But I am satisfied that the sonic benefits correlate with DA and am practicle about it. Unfinished business for someone else to explain.
Last edited:
Maybe I have the definitions screwed up but I think this would be a non-minimum phase network of R's and C's. Please help me if I am misunderstanding something here.
Attachments
- Status
- Not open for further replies.