DOEPFER / A-126-2 VC Frequency Shifter 2

Variations

The A-126-2 Frequency Shifter is a full analog frequency shifter that shifts all frequencies of an incoming audio signal by the same amount.

For example, if the shift frequency is 200 Hz, 1000 Hz shifts to 1200 Hz, 2000 Hz shifts to 2200 Hz, 3000 Hz shifts to 3200 Hz, and so on. This is different from pitch shifting, where all frequencies shift proportionally (e.g., 1000 > 1200Hz, 2000 > 2400Hz, 3000 > 3600Hz).

The frequency range of the built-in quadrature VCO is approximately 8 octaves (approximately 20 Hz ~ 5 kHz). An external quadrature VCO can be used if needed.

Controls and I/O
Frequ.1 : manual control of shift frequency (coarse)
Frequ.2 : second manual control of shift frequency (fine)
FCV in and FCV : CV input with attenuator for external CV control of shift frequency
Mix: Manual control of mix amount of up/down shifts
Mix CV in and Mix CV: Attenuated CV input for external CV control of mix amount of up/down shifts
Audio in, Level, Overload (LED): Attenuated audio Input
(standard audio input level = 1Vpp, input level should be adjusted to the point where the overload LED starts to light up slightly)
Audio Out : audio output of the frequency shifter
Squelch : control of the squelch function
Turning the knob to the left controls the VCA with an envelope follower signal. Setting the knob to the right fully opens the VCA and disables the squelch function.
VCO Outputs : Internal quadrature VCO outputs, approx. 12Vpp (+6V/-6V).
ext. VCO inputs : Used when an external quadrature VCO is used instead of the internal quadrature VCO.
VCA ext. CV : Used to control the VCA with an external CV. In this case, the built-in squelch function is disabled.
A dedicated expansion module can be used to add individual up/down shift outputs, a dome filter output, a ring modulator output, an envelope follower output, and a second audio input.

Width 8HP
Depth 60mm
Current consumption
+12V : 80mA
-12V : 70mA