3280 OTA Based kick drum & bass voice with 2 AD/AR envelopes and a 2-pole VCF.

B1is a DIY-friendly analog synthesizer module in Eurorack format. It contains everything you need to create deep, thumping kick drums or cutting bass lines in one compact 10HP unit: A 1 V/Oct VCO with 4 waveforms, a 2-way waveform mixer, 2 fast, switchable AR/AD envelope generators, a high quality VCA, and a 12db VCF for additional tone shaping! B1 also handles velocity CVs for further expression. The module is based around 3 3280 dual OTA (Operational Transconductance Amplifier) ICs for a classic sound.

Features:
+4 wave shapes: Sine + mixable with triangle, square, or 2x frequency saw
+3 use modes (kick drum AD, kick drum/bass with AD bend/filter and AR amplitude, and bass with AR bend/filter & amplitude.
+Velecity CV input
+Output directly from VCO/mixer - use as a spare VCO if needed.
+Robust old-school design with all through hole components, large copper traces, and easily obtainable replacement parts.

https://westonaudio.com/page4.html

• 80 mA +12V
• 70 mA -12V
• 0 mA 5V
• 48 mm Depth

Available as an assembled Module and as a DIY project.

This Module is currently available.