Low-distortion Audio-range Oscillator

Jump to Latest
3

31697B

Disabled Account
Joined 2012
Bob Cordell said:
It would be nice to see more detail, even schematics or at least a block diagram in the article. A bit long on boast and short on detail. He gets THD+N of 0.0004% at 1kHz and 0.00075% at 20kHz. This is about the same performance as my THD analyzer designed and built 35 years ago with 5534s.

Cheers,
Bob
Click to expand...

Yes. Not todays SOTA but it looks low cost and maybe easy to build and gives very good performance..... <-100dB re 1v. :)


-RM
 
Last edited:
S

simon7000

Member
Joined 2008
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!)))
 
scott wurcer

scott wurcer

R.I.P
Joined 2004
simon7000 said:
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!)))
Click to expand...

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.
 
Last edited:
V

vicnic

Member
Joined 2004
waltzingbear said:
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
Click to expand...

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...
 
anatech

anatech

Administrator
Joined 2004
Paid Member
Hi vicnic,
All my customers prefer PS capacitors in phono stages...
Click to expand...
... 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
 
You must log in or register to reply here.
Top Bottom