The thing...

I have been working on a combined active mult, and precision adder, for the rack over the last couple of years.

Passive mults work well enough for gates, and triggers, but splitting pitch CV quickly introduces resistive loading, voltage sag, and tracking drift. The goal here is simple: a low-noise, fully buffered mult to distribute 1V/Oct signals reliably, paired with a precision summing stage for octave transpositions, adding offsets, and combining modulation without impedance interaction.

Sourcing parts was the only friction point. The front-end circuit relies on specific low-leakage diodes for input protection to prevent signal degradation and offset drift. Finding them through the usual distributors at the moment is practically impossible with current lead times. Fortunately, I had a stash of the exact diodes tucked away in the workshop, which covers the build cleanly without needing to redesign around inferior substitutes.

Prototype, and testing!

Verification on the prototype was complete last year (I've been using two prototypes in my rack for that time). Layout and panel design are sorted, and the first small production run should be completed by the end of October.

I'll be handing at least two out to friends to test, and feedback on any concerns. It's been a fun project, and I'm already considering another...