question about audio OP amp

Scott Bernardi scott.bernardi at fritz.com
Fri Jul 10 00:09:39 CEST 1998


Depending on what voltage levels you are driving to, a 741 can give you
distortion because of slew rate limiting (0.5v/usec slew rate). An opamp
needs about 1.5v/usec to run to 20khz at +/10v levels. All of the TL-
opamps are FET based, which have higher slew rates.


At 04:20 PM 7/9/98 -0400, you 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! 
>
>Andrew
>
>| Andrew Schrock							|
>| Network Programmer, Synthesizer and electronic music enthusiast	|
>| aschrock at cs.brandeis.edu						|
>
>
>
>
>
--------------------------------------
Scott Bernardi
voice: 415-538-0439 
fax:   415-904-8375
scott.bernardi at fritz.com



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