Pro Audio Design Forum

VCAs. With a NVM DPOT on Ec.

Holy shit.

Good work Doug. WIll I be hearing the on "Undercurrents?"

Thanks for posting this John. I know that in your application that the ADI LOGDACs might be too expensive. They also zip but IIRC are monotonic in their gain steps. Have you ever tried them and is ADI still in production of these? I remember them being used in the Studer 820 and MCI/Sony APR-24.

In your second try using the NLC you mention a 10K resistor. Where was that in the circuit?

Thank you for joining us!

Interesting EE Times Article:

https://www.planetanalog.com/author.asp?doc_id=528114

Oops, wrong thread!

I think it fits here fine. One is for phones, one for transformers. Need to start one for driving cable.

It's very adaptable circuit...

Roger - Thanks. I may need to clarify something for our readers. The circuit Roger is refering to is not actually posted in this thread but is the headphone amplifier with external driver transistors. For the sake of clarity it is here: https://www.ka-electronics.com/Headphone_Amp/Headphone_Amp_1646...

That's the one I remember. Very clever.

Roger - You can indeed drop the 33R build-out to drive a transformer. It's there only for driving phones and hearing protection. Some phones in fact may sound better without it. As a direct-coupled line driver using no transformer, the circuit is capacitive load stable as well without the 33R. The o...

Those active cap multipliers with diode clamps to make it fast for large changes and slow for small changes is very similar to a circuit I did in the '80s for a NR... While I added a few other tricks too, it was the same general concept. Still found as the NLC in the Pico and THAT DN-114: http://ww...