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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.

+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.

B1 Build Information

Build Documentation (revision 05)
Bill Of Materials (revision AC)

Demo Video
Sound Samples