[sdiy] What to do with REALLY obsolete parts?

[dj hohum]

Well, the metal can op amps certainly look WAY cooler in circuits. But
most of mine are the 14 pin dip variety. My LM711s are all NOS metal
can types though.  I've certainly seem some validity in using metal
can transistors in RF circuits because the heat dissipation is better.
I can't imagine what might have been better about old metal can 741s.
Perhaps some of our list gurus can shed some light on that.

On 6/20/07, Michael Ruberto <frankentron at hotmail.com> wrote:
>
> This can depend on the circuitry. In my SEM clone VCO i had to use old can
> type 741s manufactured in the early 70s to get the damn thing to perform
> properly. The new 741s I tried just wouldn't cut the mustard for some
> reason.
>
> M. A. Ruberto
>
> >From: "dj hohum" <djhohum at gmail.com>
> >To: "Ian Fritz" <ijfritz at comcast.net>
> >CC: Florian Anwander <Florian.Anwander at consol.de>,
> >synth-diy at dropmix.xs4all.nl
> >Subject: Re: [sdiy] What to do with REALLY obsolete parts?
> >Date: Tue, 19 Jun 2007 16:45:09 -0700
> >
> >Ok, but a more modern 8 pin 741 can be used for that, correct? Is
> >there a particular reason that one would want to use the older 14 pin
> >dip 741?
> >
> >On 6/19/07, Ian Fritz <ijfritz at comcast.net> wrote:
> >>At 03:17 PM 6/19/2007, dj hohum wrote:
> >> >Well, sure. My question was more about whether they are used in any
> >> >vintage synths in any way that people want to use the original parts.
> >> >I suspect that the chips I listed won't have any value for hundreds,
> >> >maybe thousands of years :) Like old TTL chips, sometimes it's best to
> >> >just toss them out. The UA726 has become valuable because there is no
> >> >reasonable substitute, the same cannot be said for old op-amps.
> >>
> >>Once in a while the slow slew rate of the 741 is part of the design.  I'll
> >>buy 'em if you don't want 'em.  :-)
> >>
> >>    Ian
> >>
> >>
> >_______________________________________________
> >Synth-diy mailing list
> >Synth-diy at dropmix.xs4all.nl
> >http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
> _________________________________________________________________
> Picture this – share your photos and you could win big!
> http://www.GETREALPhotoContest.com?ocid=TXT_TAGHM&loc=us
>
>