[sdiy] OP275 [was: Re: Audio mixers]
pfperry at melbpc.org.au
Thu Jun 23 04:16:41 CEST 2011
On the presented evidence, I think I'd back Douglas Self against the writer
of the OP275 app notes.
1. Whatever the merits of otherwise of the front end, I doubt it is the
source of the extra distortion when feeding a 600 ohm load. This "sound of
jfet" business is just marketing BS.
2. In the app notes, a negative impedance filter is presented with the claim
that the OP275 in the frequency-dependent negative resistor is not in the
signal path... well, somebody who could say that, has a great career waiting
All in all, this shows just what we have lost with the demise of Jim
Williams and Bob Pease.
paul perry Melbourne Australia
----- Original Message -----
From: "Paul Schreiber" > From "article" (cough):
> "THD below 1 kHz is definitely non-zero with the 600R load."
> This person has outed themself as a TOTAL IDIOT and hence, everything he
> says is best avoided.
> Paul S.
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