Fantastic working unit! Original owner. Includes original box, ribbon cable, and screws.

*Will be boxed well and sent with a signature required.

Doepfer A-126-2 Voltage Controlled Frequency Shifter II

The A-126-2 module is a 100% analog frequency shifter for audio signals. A frequency shifter shifts all frequencies of the input audio signal by the same frequency.

The module has the following controls and inputs/outputs:

• Frequ. 1 : First control for manually adjusting the frequency shift as a coarse control, approx. 20Hz ... 5kHz
• Frequ. 2 : second control for manual adjustment of the frequency shift as a fine control.
• FCV In (jack) and FCV (small rotary control without knob): Control voltage input with attenuator for the externally supplied control voltage (FCV) for controlling the frequency shift.
• Mix : Rotary control for manually adjusting the up/down frequency shift ratio at the audio output; left stop = down shift, right stop = up shift; in between, a mixture of down and up shifts.
• Mix CV In (jack) and Mix CV (small rotary control without knob): Control voltage input with attenuator for the externally supplied control voltage to control the up/down ratio.
• Audio In (jack), Level (small rotary control without a knob) and Overload (LED): Audio input with attenuator, typical level 1Vpp. The Level control should be adjusted so that the Overload LED just begins to glow dimly. If the LED is fully lit, the signal is being overloaded/distorted (this can also be a desired feature). If the LED remains permanently off, the level is too low and the signal-to-noise ratio is deteriorating.
• Audio Out (jack): Audio output of the frequency shifter (output of the up/down mixer unit)
• Squelch (small rotary control without a knob): This controls the squelch function, which mutes the output signal when there is no input signal, using a VCA. On the A-126-2, this function can be continuously adjusted. With the squelch control fully counter-clockwise, the VCA is driven by the envelope signal (envelope follower). The lower the level of the envelope signal, the lower the VCA gain. With the squelch control fully clockwise, the VCA is fully open and the squelch function is disabled. The squelch control allows for continuous adjustment between these two extremes.
• Quadrature VCO outputs ( sin and cos jacks ): Outputs of the internal quadrature oscillator, each approximately 12Vpp level (+6V/-6V)
• External Sine and Cosine Inputs (jacks): These are used when an external VCO (e.g., A-143-9 with a wider frequency range, A-110-4 with Thru-Zero function, or A-110-6 with different waveforms) is to be used instead of the internal quadrature VCO. The signal levels of an external quadrature VCO should be approximately 10Vpp (8-12Vpp) and the signals must be zero-balanced. For special effects, other quadrature oscillator signals (not sine/cosine like the A-110-6 ) can also be used here, or even the signals from two different VCOs. However, the module then no longer functions as a frequency shifter but as a very specialized effects unit. The jacks are normalized to the signals of the internal VCO via the switching contacts (i.e., if no cable is plugged into the jacks, the internal quadrature VCO is used).
• VCA ext. CV (jack): This jack can be used to control the VCA with an external control voltage (e.g., ADSR). The internal squelch function is then disabled. The jack is normalized to the internal squelch control signal (i.e., if no external control voltage is applied, the internally generated squelch control signal is used to control the VCA). The VCA is fully open at approximately +8V external control voltage.