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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 08)
Bill Of Materials (revision AJ)

Demo Video
Demo/Jam Video

Sound Samples