[sdiy] lm308 replacement

[jhaible at debitel.net]

I don't know much about the RAT, but if slew limiting is part of the
sound (i.e. if it's designed that way on purpose), you will not
get this with a 071.

If you want to experiment with low slew rate / slew limiting
stuff, and if a LM324 or OP-07 (just to name two) is still
too "fast", you might want to try the LP324. It's a low power
version of the LM324 (which once was a low power opamp itself),
with 1/10 of its supply current and 1/10 of it's slew rate.

JH.

> from tinkering around with my Rat I've found that there are diodes doing the
> 
> clipping. The 308 is just being used as an amp. I have read on some sites 
> for distortion pedals that replcaing the 308 with a TL071 is a popular mod 
> for making the pedal less hissy. another mod was to use different types and 
> configurations of diodes to change the distortion sound.
> 
> ~M
> 
> 
> >From: James Patchell <patchell at cox.net>
> >To: "Steve Begin" <trypannon at hotmail.com>,   "synth" 
> ><synth-diy at dropmix.xs4all.nl>
> >Subject: Re: [sdiy] lm308 replacement
> >Date: Tue, 22 Jul 2003 16:16:14 -0700
> >
> >         Man, that is a tough one...the LM308 was just a real dog when it 
> >came to speed....something like .1 V/uS slew rate.  Also, it had super-beta
> 
> >input transistors...if the LM308 was used to make the distortion, you 
> >probably will be hard pressed to find something that will sound like it.  
> >If it was just used as an amplifier, well, probably almost anything would 
> >do...I would use a FET opamp to sub for it in that case...although, why 
> >anybody would use the LM308 as an audio amp I don't know...I suspect you 
> >have a real search on your hands.
> >
> >         -Jim
> >
> >At 03:26 PM 7/22/2003 -0400, Steve Begin wrote:
> >>I'm looking to build a proco rat distortion since it seems fairly simple 
> >>and well liked...although I'm open to suggestion (I'm looking for a hard 
> >>clipping overdrive that isn't particularily noisy).
> >>
> >>Does anybody know what I could use instead of an LM308?
> >>
> >>thanks,
> >>steve
> >
> >
> 
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