Yes. Not todays SOTA but it looks low cost and maybe easy to build and gives very good performance..... <-100dB re 1v. 🙂
-RM
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A japanese diyer's attempt "http://www.geocities.jp/cxb00463/audio/DIST/Dist_index.html"
Looks so professional.If you have questions reading machine translation text, ask me.
Looks so professional.If you have questions reading machine translation text, ask me.
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its interesting to see the results of the cap distortion test he did. too bad he wouldn't test any new COG or NPO ceramic caps to speak of.
Alan
Alan
http://www.nanovolt.ch/resources/low_distortion_oscillators/pdf/low_distortion_oscillator_design.pdf
Very good research and results. Reasonably current work.
THx-RNMarsh
Very good research and results. Reasonably current work.
THx-RNMarsh
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I can add to this, that practically all capacitors within one type may have different distortions performance. Some types are more stable, but every capacitor must be tested anyway, if the extreme performance is needed.
Hi vicnic,
I remember you saying that about the PS capacitors you were trying to use in your oscillator boards. In your application these things would be critically important.
-Chris
I remember you saying that about the PS capacitors you were trying to use in your oscillator boards. In your application these things would be critically important.
-Chris
Hi Chris,
Yes. Now I can say that also about the PP capacitors including Wima FKP2 and FKP3. Some examples of them have have more visible distortions.
Victor,
are you talking about "small" differences in distortion level between units in a lot or large outliers in distortion level within a lot?
Cheers
Alan
are you talking about "small" differences in distortion level between units in a lot or large outliers in distortion level within a lot?
Cheers
Alan
I guess that makes sense. That means that distortion performance is dependant on manufacturing processes that wouldn't change the value. I'm wondering if the dielectric could have variable contaminants.
-Chris
-Chris
I think I mentioned this before. I took 10 capacitors did the 4/1 1/4 bridge and measured the distortion. I then put all ten as assembled into a can of desiccant for about a year. When dried out the distortion was less. If I get really bored I might try to find the before and after shots. (Might have shown this on the blowtorch rope. ((It no longer qualifies as a thread!)))
Ed I think what you did is good but looking a Samuel's numbers this can be a don't care issue. If an NPO cap is -143dB today and -133dB tomorrow, there has to be a better place to spend your time. By simple physics passive component nonlinearities tend to be low order and amplitude dependent, the answer (if there is one) is not here.
EDIT - Of course if you want to make a device that makes certain numerical benchmarks it might matter.
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Scott,
Our usual...
My measurements were on film capacitors and I have no idea if they apply to ceramic types.
The capacitors in use also seem to dry out. So there actually may be a performance increase after a burn in period.
ES
Our usual...
My measurements were on film capacitors and I have no idea if they apply to ceramic types.
The capacitors in use also seem to dry out. So there actually may be a performance increase after a burn in period.
ES
Yes, both these situations were observed. Probably the manufacturer can't control the distortions, and we can only guess about the reasons of these differences.
In the same time absolutely curious for me is the sounding difference between the good PP and PS capacitors which both have distortions lower than -155dB@1kHz. All my customers prefer PS capacitors in phono stages...
Hi vicnic,
-Chris
... and in their amplifiers and tone stages too. I'm included in that as my own preference includes good polystyrene capacitors. I'm not sure if I could hear the difference between polypropylene and polystyrene caps. They really cover two different ranges of values with a little overlap. Therefore I tend to use both types in my work.
-Chris