[sdiy] LM301 vs LM308 in feedforward compd filters

[Michael Ruberto]

One device I can think of which depends on the LM308's slowness for it's 
sound is the ProCo Rat pedal. This pedal is generally terrible sounding for 
guitar but I kept mine almost permanently plugged into my old Prophet 600. 
For some reason that pedal could do wonders for that synth. It didn't sound 
good on anything else in my studio either. The nice thing was the knobs and 
finish on the pedal were an exact match for the P600.

Oh and the LM308 works pretty well in my power supply. I guess it's all that 
mumbo jumbo about the input circuits that helps here... ;)

M. A. Ruberto


>From: Ian Fritz <ijfritz at earthlink.net>
>To: Bob Weigel <sounddoctorin at imt.net>, Michael Ruberto 
><frankentron at hotmail.com>
>CC: aankrom at bluemarble.net,synth-diy at dropmix.xs4all.nl
>Subject: Re: [sdiy] LM301 vs LM308 in feedforward compd filters
>Date: Thu, 04 Aug 2005 08:16:23 -0600
>
>At 11:39 PM 8/3/05, Bob Weigel wrote:
>>The 308 was developed as a 'tight spec' amp with very nice input design 
>>having exceptional characteristics for a bipolar on offsets and input bias 
>>particularly.  Naturally there are compromised aspects that result in 
>>other areas and slew rate would be a logical one to suffer. They appear in 
>>some old instrumentation circuitry but I seldom see them find use in music 
>>applications though I have seen them a time or two. Trying to recall 
>>where.
>
>They were used in many of the Enotes designs where low input bias current 
>was needed.  This was before the FET-input devices (TL07x) were developed.
>
>