Doepfer has always been known to produce premium quality modular synth equipment and the Doepfer A-126-2V Voltage Controlled Frequency Shifter II Eurorack Module is not an exception. The module is a fully analog frequency shifter for audio signals, capable of shifting each frequency of the incoming audio signal by the same frequency without altering the pitch. With just a few controls, inputs, and outputs, you can create a shift in frequency with an external voltage or mix the up and down signals.
What sets the A-126-2V apart from other frequency shifters is its remarkable frequency range. With a range of up to 8 octaves, which is about 20Hz to 5kHz, you can have a lot of room to explore. Furthermore, this module is equipped with an internal quadrature VCO, which allows even very low frequency shifts. The frequency control has two manual controls that allow you to set a frequency range, and controls FCV In and FCV can be used to control the shifting frequency voltage externally.
The A-126-2V Voltage Controlled Frequency Shifter II Eurorack Module is equipped with a 12-stage Dome filter that generates 90 degrees phase shift with less than 0.3 degrees error over a frequency range of about 50 Hz to 14 kHz. The filter is made with close-tolerance parts, which avoids the adjustment of many trimming potentiometers with mutual influence. Besides, the module has a ring modulator and multiplications circuits to enable adding or subtracting the frequency in a time-efficient manner.
In addition to the aforementioned features, this frequency shifter module also comes with an envelope follower to derive an envelope signal from the audio signal. The envelope signal is then used to control a VCA which works as a squelch unit. With external control voltage applied, the up and down signals are mixed at the output using voltage controlled crossfader and can be manually controlled. Its fully DC coupled attribute allows for even very low frequency shifts with external quadrature VCO.
In summary, the Doepfer A-126-2V Voltage Controlled Frequency Shifter II Eurorack Module provides an innovative way of dealing with frequency modulation to create vibrant soundscapes. Its features, which include the dome filter, ring modulators, and envelope follower, offer a range of creative possibilities for frequency shifting in electronic music.
Example Usage
If you're new to frequency shifters and want to experiment with the Doepfer A-126-2V Voltage Controlled Frequency Shifter II Module, try using it on a simple synth lead or melody line. Connect the audio output of your synth to the A-126-2V audio input, adjust the level control to avoid clipping, and turn both manual frequency controls to their lowest position. Gradually increase the first manual control to shift the frequency of the lead up or down. Use the Mix control to adjust the balance between the original and shifted signals. You can also experiment with using external control voltage input to modulate the frequency shift. Have fun exploring the unique sound possibilities of the A-126-2V!
An intermediate-level usage example for Doepfer A-126-2V Voltage Controlled Frequency Shifter II Eurorack Module is to create a complex chord sequence with shifting frequencies that can be controlled with an external voltage source. To achieve this, connect a keyboard or a sequencer to the FCV In input and adjust the Frequ. 1 and Frequ. 2 controls to achieve the desired up or down frequency shift. Then use the Mix control to adjust the panning of the shifted signals and mix it with the original signal. Finally, use an LFO or an envelope generator to control the Mix CV In input to create evolving and dynamic chord sequences. The result is a rich and unique sound that can add depth and complexity to any musical composition.
Further Thoughts
An advanced technique that can be used with the Doepfer A-126-2V Voltage Controlled Frequency Shifter II is the creation of phantom harmonics. This is accomplished by using an external sine wave oscillator to produce a waveform with a frequency that is exactly double that of the incoming audio signal. By feeding this external oscillator into the A-126-2V and adjusting the shifting frequency controls appropriately, the resulting output will contain artificial overtones that are not present in the original audio signal. This can lead to some truly unique and ethereal sounds that can add a haunting quality to any musical composition.