Bullfrog XL Educational Semi-Modular Synthesizer

Born from a collaboration between Erica Synths and Richie Hawtin, this beast triples the size of the original Bullfrog, turning a hands-on learning tool into a classroom showstopper or studio centerpiece you can actually see and patch from across the room.

At its core sits a fully analog subtractive engine with a single VCO offering precise 8-octave tracking, voltage-controlled waveshapes from sine to shark-fin and PWM pulse, plus a zener diode noise generator for gritty textures. Sound shapes up through a resonant 24dB/oct lowpass filter, then a VCA with built-in delay effect for spacious echoes, all modulated by dual looping ASR envelopes that double as LFOs, a sample & hold with its own clock, and utilities like attenuverter, slew, splitter, and divider. Patch with 1/4" cables or snap in voice cards—included ones cover sequencer, sampler/looper, acid bassline, hipass filter, LFO, and electric organ, plus DIY blanks to experiment. Massive at 36 x 22 x 8 inches and 8.3kg, it packs built-in speakers, a two-channel oscilloscope to visualize signals, stereo headphone out, line-level 1/4" output, MIDI DIN/USB, CV/Gate, and USB-C power.

Since its 2024 debut, it's earned praise for demystifying synthesis—kids and pros alike dig the instant gratification of voice cards and the scope's real-time feedback, though some note the lo-fi sampler's quirky learning curve adds to the fun.