Hybrid (transistors and tubes) transformator ring modulation unit with bipolar control voltage inputs and DC offset control. Since it’s DC coupled, work as bipolar VCA is possible. Being rather aggresive, Austin creates rich harmonic content with help of discrete differential pair design (soft, symmetrical, sinewave-like clipping) and two-stage Nuvistor amplifier (asymmetrical clipping with characteristic sound of saturating tubes). 2V p-p signal is sufficient for nice overdrive.
Intuitive LED feedback will show modulation input amount and polarity. When driven by audio rate signal, spotting beat frequency patterns is possible.
Controls (from top):
- Audio input level
- (+) carrier (modulation in) level
- (-) carrier (modulation in) level – when nothing is plugged in, fixed control voltage in range of 0..+6V is applied to (-) modulation input.
- 5HP / 60 mm depth
- current needs: +12V: 150mA, -12V: 20mA
- quite hot tubes inside – make sure you don’t have temperature sensitive modules nearby!
- transformers inside – make sure you don’t have EMF-generating modules / PSU nearby!