Another follow-up. I put together a really simple test circuit with some potentiometers, but I don’t have all the capacitor values on hand to match the circuit above. I could probably run some in parallel but my head’s hurting too much at the moment to be bothered digging through things. The bad substitute values I put in did nothing for the filters, regardless of the levels I attempted to set (at least as far as I could tell with the test audio I was pushing through) so I’ll have to come back to that in a week or two.
On the upside, the balance control and, more importantly, volume control worked exactly as you’d hope. Connecting the output from my ADSR module to the volume CV input made a nice enough VCA for me to consider using these chips to make some properly. I have a homemade power supply that gives me +5V as well as +/-12V; as long as you’re running the TDA1524 on more than 10.8V you can connect pin 17 (used for the potentiometer reference) to 5V and that makes voltage control from other circuitry nice and easy.
I’m rather pleased with these chips. I’ll get some decent capacitors next time I’m doing an RS order and make something on a perfboard.