The Bullfrog is a 100% analog educational synthesizer designed by Erica Synths and Richie Hawtin. It is a semi-modular subtractive synthesizer intended to teach the fundamentals of sound synthesis while inspiring both beginners and experienced musicians.

The Bullfrog consists of several classic analog modules: a highly accurate voltage-controlled oscillator (VCO) tracking over 8 octaves, a zener diode noise generator, a resonant lowpass voltage-controlled filter (VCF), a VCA with adjustable offset, and a delay effect. Control signals are provided by two ASR envelope generators and a sample & hold circuit. The instrument uses eurorack patch cables to connect modules, or the included voice cards that create internal patch connections and add extra functionality.

What is included: Bullfrog synthesizer, universal 12VDC power adapter, user manual, 10 patch cables, 3 pre-patched voice cards (Sequencer, Acid Bassline, Sampler Looper), and 3 DIY voice cards. Dimensions: 40 x 385 x 210 mm, weight: 1.8 kg. Features DIN5 MIDI input, USB connector, and a built-in speaker.