• analog synthesizer
• monophonic
• oscillator with waveshaping
• noise generator
• Mixer
• lowpass filter
• VCA
• Delay effect
  
• 2 loopable A/R envelopes
• Sample & Hold with Pulser
• Divider
  
• Loudspeaker
• Slot for voice cards
• USB-C input
  
• MIDI In
• Audio Out
• CV/Gate In
• Headphone Out
• incl. 10 patch cables, 10 Patch templates, 3 ready-made voice cards, 3 DIY voice cards, power supply unit
  

The sound generation in detail

The heart of the Bullfrog is the analog oscillator with a precise Tracking of over eight octaves and waveshaping waveforms. Sine goes through a transformation all the way to shark loops, and square is modulatable in pulse width. The two waveforms of the oscillator can be tapped in the mixer and can be replaced by another signal at the inputs. In the mixer you also get access to the level of the noise generator, at the mix output all three signals run together. If you stick exactly to subtractive synthesis, the resonant Lowpass filter is the next element in the signal path. Two control voltage inputs, one of them with attenuator, bring life into the patch. The audio path is completed by the VCA with adjustable Offset and the fixed delay effect. Connoisseurs can already guess what sounds the Bullfrog is capable of.

Three modulation sources for varied sounds

Two identically constructed attack/release envelopes are used to modulate all CV inputs. Thankfully, the envelope parameters can be modulated separately via CV. Additionally, a switchable loop mode is integrated, which turns the envelope into an LFO. Waveform and speed of the LFO in this case is also set with Attack and Release . The sockets EG1/2 Out carry the positive voltage curve of the envelopes, bipolar voltages are applied to BP, with these the full potential of the Loop-Mode is exploited. Strictly speaking we are dealing with two simple function generators. The sample & hold circuit is primarily there to generate random stepped voltages. In the Bullfrog this happens in time with the pulser or based on played notes as "gated S&H". Not to be left unmentioned is the divider, which becomes a sub-oscillator with four subordinate octaves at the square wave output of the oscillator or allows very experimental patches when it is clocked by the pulser of the S&H and connects the divider taps with the two envelopes.