I built another Nonlinearcircuits Dual LFO/VCO module, this time for Eurorack. I have one in my NLC Banana Jack panel. I left off the Sync and Step functions and the LEDs on the banana panel, due to lack of space. Here I got to include everything.
A neat feature of this dual oscillator is the sample and hold circuit that produces the Step output. The oscillator’s own Sine output is sampled at the rate of the other oscillator. This produces a stepped output that is patterned by the frequencies of the two oscillators. I made a modification to the S&H circuit by using 10nf capacitors instead of the listed 1nf. I did it because I noticed a significant droop on the steps with the 1nf value. The 10nf caps worked great.
As with the other Dual LFO/VCO (in the banana panel), I omitted one of the 10uf caps for the low range just because I didn’t want it to go that slowly.
I didn’t use 1K Tempco resistors, but placed normal 1K SMD resistors on the underside.
Three 10-pin inline headers, Mouser #710-61301011821 and #649-1012937892001BLF, are used to interconnect the boards. I used the optional 11mm standoff to secure the boards together.
The center off toggle switches are Mouser #506-A103SDZQ04. The trim pots user are #858-67YR10KLFTB, even though the pins don’t line up.
I used the NCL black panel. It matches well next to the other modules in my modulators case. My Bananut colors are Silver (white) for triggers and gates, Blue for CV in, Red for pulse/square outputs, and Black for other outputs. There’s just enough clearance for Bananuts on this panel.
