question about audio OP amp

[Scott Gravenhorst]

On Thu, 9 Jul 1998 16:20:08 -0400 (EDT), Andrew Schrock
<aschrock at cs.brandeis.edu> wrote:

>On Thu, 9 Jul 1998, Johan Persson wrote:
>> As a novice in the art of OP's, I used the TL072 as an audio OP in a
>> Paia Fatman mod and I'm not really sure about this... Has anyone any
>> suggestions to a simple, good OP to use with audio?
>
>Johan,
>
>You should be fine using any garden-variety op-amp.. TL082, TL072, even a
>741 would be fine. I use TL082's since they're cheap, decent quality, and
>is a dual vs. a single. 
>
>Are you working on the audio input mod? If so IMO it's cool to decrease
>the value of a critical resistor (marked r_gain on scott's mod gif) to
>overdrive the circuit slightly. I have mine overdriving my input by maybe
>a factor of 2, so that when the ex. in volume is up all the way the input
>sound slightly distorts, but when it's at 1/2 the sound is just filtered
>normally. Handy! 

Mind if I pipe in?  <g>  r_gain can be a variable resistor (pot) wired
like a rheostat like mine (use the center pin and one side, making
sure that when fully clockwise you get max resistance).  I didn't draw
it that way because pots are more expensive than fixed Rs and panel
space is always a problem.  My unit actually has a gain pot and a
level pot.  The gain pot goes from a gain of 1 to around 450 when wide
open.

-- Scott Gravenhorst
-- FatMan Site: www.teklab.com/~chordman