data books, PMI

Russ L askeyman at
Tue May 5 04:49:03 CEST 1998

Tony, Tony, Tony,

How about talking one of your old buddies into manufacturing the
SSM2033, 2040, and some of the other great old chips. I have been
tempted lately to call Analog Devices to see if it's possible, if the
demand warrants it. I wish I worked at a synth chip company.

BTW I have a copy of copy of the PMI audio handbook Volume I.

Russ L
askeyman at

Tony Allgood wrote:

> Scott wrote:
> Ever hear of the OP-27 (low noise, high speed, hi preceision opamp)? I was
> a co-designer on that, and the metal mask still has my initials on it. I
> use OP-27's instead of 741's because I had 150 or so of them from a
> pre-production run (only about 50 left).
> Well I did this in a variety of applications... but in some cases, the swap
> really causes more troubles. If the OP-27 is used as a voltage follower,
> then don't take the input too near the supply line because you will have a
> very nice 1MHz oscillator. Took me ages to find the source of that. The
> follower drove a 3080 VCA to control the ADSR envelope amount. But this 1MHz
> was everywhere, audio outs, CV and even the so-called ground line. Another
> time was in a tracking PSU. I had a good old 723 running the positive at
> 15volts, and a 741 op-amp driving a pass transistor to give the minus.
> Replaced the 741 with a OP-27... and honk city. Sometimes you just can't get
> slow enough.
> Regards,
> Tony Allgood, Cumbria, UK
> e-mail: oakley at
> My latest project; a rack mounted VCF module with warmth. PCB arriving soon.

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