[Fwd: Re: Op Amp pinouts was Re: [sdiy] more LM3900 stuff]

[Pat Kammerer]

----- Original Message -----
To: Synth DIY <synth-diy at dropmix.xs4all.nl>
Sent: Tuesday, January 17, 2006 1:55 PM
Subject: Re: [Fwd: Re: Op Amp pinouts was Re: [sdiy] more LM3900 stuff]


>
> > I find that at low supply voltages the OP275 distorts undesirably.  I
> > find
> > that a much better alternative is the OP270.
> >
> >
> >
> But at higher supply and signal voltages you might find the opposite is
> true - the slew rate of the OP275 is ~10 times the OP270.  The offset
> voltage and drift is however much smaller for the OP270 which might be
> useful in applications which handle pitch CVs as well as audio.
>
> Seb

I find that with a +/- 12V supply, the apparent sound quality (by ear) and
waveshape (as veiwed on oscilloscope) is better in audio applications such
as VCA, preamp, equalizer, and buffer.  I generally use a higher slew rate
amp when summing CVs and related applications.  I have trouble beleiving
that the slew rate is the primary cause of the distortion that I have
noticed when using the OP 275, wouldn't it mostly indicate that a larger
bandwidth is possible without loss in linearity?