Behringer TD-3-GP

Behringer TD-3-GP Analog Bass Line Synthesizer — Acid House DNA in a Desktop Module

The Behringer TD-3-GP is an all-analog recreation of the Roland TB-303, the bass synthesizer whose squelching resonance defined acid house, techno, and electro from the early 1980s onward. This purple desktop module delivers the throbbing, greasy character that made the original a cult classic, built around a true analog signal path with matched transistors. A single voltage-controlled oscillator feeds a 24 dB/octave four-pole resonant low-pass filter, giving every note that unmistakable bark and slide — perfect for electronic producers wanting hands-on acid bass programming without paying vintage prices.

What Sets This Synth Apart

Unlike purely digital clones, this model preserves the original's matched-transistor VCO with transistor waveshaping circuitry, generating reverse-sawtooth and pulse waveforms that respond to filter and envelope modulation like the 303 did. A dedicated distortion circuit modeled after the Boss DS-1 adds extra grit, while Poly Chain lets users daisy-chain multiple units for up to 16-voice polyphony.

Analog Synthesis Engine — Pure VCO/VCF/VCA Architecture

The synthesis core gives this unit its unmistakable voice. Every stage of the signal path is analog, so modulation behaves continuously rather than in stepped digital increments.

• Oscillators: Analog VCO — single oscillator with switchable sawtooth and square waveforms
• Filter: 4-pole 24 dB/octave resonant low-pass VCF — provides the squelchy, self-oscillating character of the original 303
• Envelope: 1x EG — single envelope generator shaping both filter and amplitude
• LFO: 1x LFO — adds slow modulation movement to filter cutoff or pitch

Sequencer and Performance Controls — Pattern-First Workflow

Built around step sequencing rather than keyboard performance, the layout mirrors the original 303 workflow with real-time recording and step programming both feeling immediate.

• Sequencer: 16-step, 7-track — supports accents, slides, and rests with up to 250 user patterns
• Keyboard: 13 mini key buttons — unweighted action for pattern entry and live tweaking
• Polyphony: 1 voice (monophonic) — chainable to 16 voices via Poly Chain
• Controls: 11 knobs and 28 switches — direct, real-time access to every important parameter without menu diving

Connectivity and Build — Studio-Ready I/O in a Compact Footprint

Despite its small size, the synth integrates into a modern hybrid rig with both legacy DIN MIDI and USB-MIDI, plus a full complement of CV/Gate patch points.

• MIDI I/O: 5-pin DIN In/Thru plus USB-B (MIDI) — class-compliant on Windows and macOS
• CV/Gate: 4x 3.5 mm patch points — filter CV input, CV input, and dual CV outputs
• Audio I/O: 1/4" TRS line out and 1/8" headphone output (32 mW)
• Dimensions: 305 x 165 x 56 mm — Weight: 0.8 kg, 2 W AC/DC adapter included

Who This Synth Is Built For

This synth suits electronic producers, beatmakers, and sound designers who want authentic acid bass tones without the cost or scarcity of a vintage TB-303. It works for techno, house, electro, and drum-and-bass producers building sequenced bass lines, plus live performers wanting hands-on pattern triggering on stage. Modular users will appreciate the dedicated CV/Gate patch points for integrating the synth into a Eurorack setup, while beginners benefit from a tactile, no-menu workflow that makes pattern programming approachable.

The Behringer TD-3 and the Legacy of the TB-303

The original Roland TB-303 was released in the early 1980s as a budget accompaniment device for guitarists, paired with the TR-606 drum machine. It was a commercial failure at launch, but Chicago and Detroit DJs and producers discovered its squelching resonance could define entire new genres — most notably acid house. Behringer's TD-3 brings that same circuitry back to contemporary producers with matched transistors, the classic 24 dB/octave filter, and modern additions like USB-MIDI. The TD-3-GP is the purple "Grape" color variant in the lineup.