[sdiy] using a dac as a digitally controlled amplifier

[Rainer Buchty]

On Sun, 4 Aug 2024, Gordonjcp wrote:

> The Ensoniq DOC chip uses the same trick for the same reason.

To my understanding, it even saves on the amount of DACs and instead 
S&Hs the volume voltage, then using that as the waveform reference 
value for the "main" conversion.

Can be seen on the first-generation Mirages featuring the Rev A DOC 
where the S&H stuff is spelled out externally.

With Rev D, almost everything vanished inside the chip w/ only some 
external feedback signals pointing to it (VVref=-5V, WVref, Vlfdbk, Vol-).

Rainer