Modular synth audio signal buffering

[alkopop79]

I'm designing a modular synth based on the Sound Semiconductor VCO, VCF and VCA ICs. The datasheet has application circuit schematics for each IC. I wonder, do I need to place op amp buffers on the audio outputs and inputs? Say, does the VCO need output buffering?

https://www.soundsemiconductor.com/

[kkissinger]

Looks like the buffers are built-in to the chips (though I did not check all of them). Note that the Peak-to-Peak level is 2.5 volts so you will need external parts if you want to change the levels (i.e. 10volt p-to-p).

Are these expensive chips? I didn't see prices for them on the website.

[blue hell]

[kkissinger]

Wow, I did not expect these chips to be so inexpensive.

Page 21 of the datasheet shows that the output from the VCO chip is from it's internal mixer and does not require an external buffer. If your design uses phone plugs and jacks, I would suggest use of a 1000 ohm resister at every output point to protect the output circuit from contacting ground when plugging in patchcords.

Will look forward to reading your progress on this.

[alkopop79]

[alkopop79]