[sdiy] THAT2180A

[Dakota Melin]

I’ve done some simulations but haven’t made the PCBs yet. The familiar
“linearized 2164” circuit can be adapted to make the equal power curve
instead of linear.

David Dixon mentioned it awhile back and then I started messing around with
it. According to the sim I set up, the CV curve was a recognizable to the
Serge style equal-power-curves.

-dk

On Fri, Nov 27, 2020 at 7:15 PM S Ridley <spridley1 at gmail.com> wrote:

> >  Separate question: Is there any analog way that *does* give a constant
> power panning curve?
>
> Serge Modular were keen on equal power panning.  I think they did some
> square root stuff by logging the CV, halving it and letting the expo
> response of the VCAs do the anti-logging.
>
> Steve
>
>
>
>
>
>
>
> <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> Virus-free.
> www.avast.com
> <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail>
> <#m_8653345436917580256_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
>
> On Fri, 27 Nov 2020 at 20:08, Tom Wiltshire <tom at electricdruid.net> wrote:
>
>> Do you mean this one? “VCAs in a Pan potentiometer Application”:
>>
>> http://www.thatcorp.com/datashts/dn120.pdf
>>
>> Personally, I never liked the hacky make-it-nonlinear approach. In
>> practice it works more than well enough. If it was me, I’d use a lookup
>> table and a DAC. Whatever floats your boat, I guess…;)
>>
>> Separate question: Is there any analog way that *does* give a constant
>> power panning curve? I remember seeing the “expo crossfade” example from
>> the SSM2024 datasheet which uses a differential pair to split a linear
>> control current between two linear VCAs (e.g. not applicable to the expo
>> VCAs we’re discussing here) . If I remember correctly, when I tried it, it
>> gives subtle “hole in the middle” effect as a panner, as the volume
>> apparently drops as the signal reaches the centre. This experiment was a
>> long while ago though, and I might be mis-remembering.
>>
>> What others have said about the VCAs is all true - you pick the
>> cost/quality ratio you’re after and then the parts choice will make itself!
>>
>> Tom
>>
>> ==================
>>        Electric Druid
>> Synth & Stompbox DIY
>> ==================
>>
>>
>>
>> On 27 Nov 2020, at 16:27, Ben Gebhardt via Synth-diy <
>> synth-diy at synth-diy.org> wrote:
>>
>> I second what Eric said and would note that THAT has a good app note for
>> a pan pot application which I used for a mastering grade cross fader. Worth
>> a look.
>>
>> On Nov 27, 2020, at 10:50 AM, Eric Schlappi <eric.schlappi at gmail.com>
>> wrote:
>>
>> 
>> if you are going off of the THAT Corp app note for equal power panning,
>> it is totally possible to adapt that to the ssi2164. Just change the
>> scaling and you need to invert and offset one side.
>>
>> On Fri, Nov 27, 2020 at 7:27 AM drheqx <drheqx at gmail.com> wrote:
>>
>>> I'm looking at the THAT2180A for a voltage controlled pan pot
>>> application. They're not cheap. Any ideas for a less expensive vc pan pot?
>>>
>>> Mike
>>> _______________________________________________
>>> 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
>>
>> _______________________________________________
>> 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
>>
>
>
> <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> Virus-free.
> www.avast.com
> <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail>
> <#m_8653345436917580256_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
> _______________________________________________
> 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
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20201127/f5dc69d6/attachment.htm>