Doepfer A-134-1 VC Panner/Crossfader

The Doepfer A-134-1 VC Panner/Crossfader is a module with a lot of purposes. Use it as a 2-channel mixer, a dual VCA, a crossfader, or with the right amount of rectangular modulation, it can be used as a switch. Users rarely would rarely part with this module.

The Doepfer A-134-1 VC Panner/Crossfader is a voltage controlled universal panning and/or crossfader module. If the module is used a voltage controlled Panning device one audio signal is panned to two different outputs. If the module is used a voltage controlled Crossfader two audio signals are mixed to one common output. The module enables even compositions of both functions. The module contains two linear high quality VCAs (made with CEM3381/PA381 until April 2013, SSM2164 from May 2013). VCA2 works in the opposite direction of VCA1 i.e. the more VCA1's loudness increases the more VCA2's loudness decreases. The panning or crossfading is adjusted with a control knob (manual control) and by two external control voltages, one equipped with an attenuator. Suitable control voltage sources are e.g. LFOs (A-145, A-146, A-147), envelope signals (A-140, A-141, A-142, A-119), random (A-118), Theremin (A-178) or a voltage coming from an MIDI-to-CV-Interface (A-190, A-191).

The panning/crossfading is displayed with 2 LEDs. A-134-1 has an audio input with attenuator for each VCA. If the audio input of VCA2 is not used the audio input of VCA1 is connected with audio in of VCA 2, i.e. the sockets are "normalled". The module has three audio outputs: Left Output (VCA1), Right Output ( VCA2) and Mix. For Panning applications the outputs Left Out and Right Out are used. If the module is used as as Crossfader the Mix Output functions as output. Module A-134-1 enables voltage controlled stereophonic panning effects (one audio signal distributed to two outputs), crossfading effects (two audio inputs mixed to one audio output with voltage controlled loudness proportion) and combinations of both effects. For more detailed information please look at the English user's manual.

Version 2 of module A-134-1 is able to process even slowly varying control voltages as the in/ouputs are DC coupled. Version 2 is manufactured from about May 2013 and can be identified by the SSM2164 VCA circuit (16 pin circuit labelled SSM2164 or V2164).

These VCAs are able to process even slowly varying control voltages: A-130/A-131 (only the new versions with CA3080 or SSM2164 or THAT, not the old versions with CEM3381/PA381/CEM3382) A-132-1 (all versions) A-134-2 (all versions) A-135-1 (only the new version with SSM2164/V2164, not the old versions with CEM3381/PA381)