The AJH Synth Vintage Transistor Core VCO is a Eurorack oscillator based directly on the earliest, fully discrete transistor VCO card used in the original R A Moog Model D. This version recreates the circuit topology and waveform shaping of that rare design, offering sawtooth, triangle, square with full PWM control, and the distinctive “sharktooth” output, along with front-panel octave switching.
To improve reliability for modern use, AJH redesigned the control voltage summing stage to correct the temperature instability that affected the original units, using contemporary precision components. The audio path and wave-shaping circuitry remain unchanged from the vintage design, preserving the original sonic character while delivering far greater tuning stability. Additional features include linear and exponential FM inputs and two oscillator sync modes, making it a flexible standalone VCO.
14 hp, 38 mm depth, +12V 55 mA, -12V 40 mA
Includes ribbon cable.
Video: https://youtu.be/Xlhl8LkxjsM
Product Specs
- Item Number: 41135
- Make: AJH Synth
- Model: Mini Mod Vintage Transistor Core VCO
- Condition: Very Good
- Categories: keyboards-and-synths ⇒ eurorack
- Function: Oscillator
- MPN: 41135
- Modular Grid: Eurorack ⓘ ＋
- Dimensions*: 14 HP 34 mm deep
- Power*: 55 mA +12V 40 mA -12V 0 mA 5V
* User contributed details