[sdiy] what opamp for "warmth"? (I know, I know...)

David Huss dh at atoav.com
Wed Apr 5 17:19:16 CEST 2023


Instead of relying on some opamp characteristics I would probably just take any opamp and then add the nonlinearities in circuit. E.g. a Opamp that drives a pair of antiparallel diodes (to GND for soft clipping, in series with the signal path to create zero-crossover distortion). Adjust to taste by diode choice/combination. If that is all to much, blend with the clean signal.

On April 5, 2023 2:59:54 PM UTC, Jacob Watters via Synth-diy <synth-diy at synth-diy.org> wrote:
>I like to use a 4069 for that. Just make sure you use schottky diodes to
>protect the input. It is good to use on a single power rail too. I have
>made little overdrive boxes that are just a single 4069 with stereo
>overdrive and 6db filter.
>
>*Jacob Watters*
>JacobWatters.com <http://jacobwatters.com/>
>
>
>
>On Wed, Apr 5, 2023 at 10:40 AM S Ridley via Synth-diy <
>synth-diy at synth-diy.org> wrote:
>
>> Neil
>>
>> If it has to be an opamp solution, the LM324 *might* be worth a look.
>> It's output is known to produce significant crossover distortion under
>> certain conditions - also, it's a single rail device so will still give
>> some headroom from a +9v supply.  (It's also easily available and cheap.)
>> OTOH crossover distortion will give mainly odd harmonics, and you'd have to
>> make sure the output isn't sourcing current at mid rail voltage output -
>> the usual fix for the crossover distortion is a resistor to -ve supply.
>>
>> There's some discussion here:
>>
>>
>> https://electronics.stackexchange.com/questions/341843/adding-a-resistor-to-reduce-crossover-distortion-in-an-lm324-lm358
>>
>> Might be too subtle for your needs.
>>
>> Steve
>>
>>
>> On Mon, 3 Apr 2023 at 22:21, Neil Harper via Synth-diy <
>> synth-diy at synth-diy.org> wrote:
>>
>>> i know this is going to be controversial, and I'm grabbing my popcorn..
>>>
>>> i have a digital effect that I'd like to "warm up" in the last dry/wet
>>> mixing and output buffering stage. So wondering if there's any choice of
>>> opamp that might give some favorable non-linearity quality to the output
>>> sound. Would be running them with a single supply +9V.
>>>
>>> as for what specs constitute "warmth", I'll leave that up to you.. :)
>>>
>>>
>>>
>>> --
>>> /// Neil Harper
>>> /// Every Wave is New Until it Breaks
>>> _______________________________________________
>>> Synth-diy mailing list
>>> Synth-diy at synth-diy.org
>>> http://synth-diy.org/mailman/listinfo/synth-diy
>>> Selling or trading? Use marketplace at synth-diy.org
>>>
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at synth-diy.org
>> http://synth-diy.org/mailman/listinfo/synth-diy
>> Selling or trading? Use marketplace at synth-diy.org
>>



More information about the Synth-diy mailing list