[sdiy] Trueno

[Neil Johnson]

Hi Roman,

> One of my fb friends has just bought the Trueno synthesizer and by my polite
> request, he made a photo of inards at better angle than the one on maker's
> website. Photo of the other side tomorrow - he says.

Interesting idea.

> My first thought when I saw it was ASM-1 or MFOS, but that's probably just
> because of generous amount of TL074. Plus 3x 4051 mux.
> Obviously on the other side will be some ARM or whatever to deal with USB,
> ADC and control voltages, DC/DC converters, and something tunable for the
> filter (OTA, or transistors), because it's only one 074 outlined there as
> VCF with only few passive components.

VCF is most likely a clone of the Polivoks filter.  Their about page says:

"Trueno’s filter is based on a soviet Russian design known for its
unmatched harsh, aggressive sound."

So I'm guessing something like an LM4520 programmable opamp.

Neil
-- 
http://www.njohnson.co.uk