Control Synthesis Deep Bass Nine

Back in 1994, this rackmount beast was custom-built by Control Synthesis for a UK vintage gear shop hungry to feed the TB-303 craze, delivering a no-frills analog bass module powered by the legendary CEM3340 VCO chip that also drove classics like the Roland SH-101.

It's a 1U heavy hitter with a sturdy metal case and built-in power supply, sporting just 10 front-panel knobs for instant access: waveform switch between saw and square (plus a crossfade option via external input), tuning, filter cutoff and resonance on its squelchy 24dB/oct ladder lowpass, env mod, decay, accent (velocity-triggered for that 303-style filter punch), and volume, plus a MIDI channel selector. MIDI In/Thru handles note velocity for accent and CC control for cutoff and glide (toggled via CC#5), while CV/Gate In/Out and clock ports make it a handy MIDI-to-CV converter for older synths; audio in lets you filter external signals, all feeding a single mono voice with fixed fast attack/release envelopes tuned for bass duties over an 8-octave range.

Owners cherish its raw, warm thump—deeper and punchier than many 303 clones in a live chain—though its lack of sequencer, patch memory, or knob-to-MIDI output keeps things old-school purist, earning nods from techno heads who value the straightforward acid growl without the vintage markup.