A-132-3 Dual linear/exponential Voltage Controlled Amplifier

The A-132-3 Dual Lin. / Exp. VCA has two identical sub-modules. Both amplifiers can be switched independently between linear and exponential characteristics.

In addition, there is a clear and solid equipment (CV input with attenuator and manual “gain” control), so that the module is very versatile.

User interface

Inputs (for each of the 2 sub-modules):


Outputs (for each of the 2 sub-modules):


Controls (for each of the 2 sub-modules):


One for all

The module can be used very well both for audio signals (then often with exponential characteristics) and for the amplification of control voltages (usually with linear characteristics).

Module versions – from Curtis to SSM and back

In earlier versions, a CEM3360 was used for the VCA, which was no longer available from 2010. An SSM2164 was therefore used from autumn 2010 onwards.

The “old” A-132-3 worked practically without distortion due to a limitation of the gain factor to 1 and a very generously dimensioned “permissible” input voltage of up to +/- 7.5V. A great and completely uncomplicated VCA if you don’t want to “color” the sound further through the amplifier. For this reason, an A-132-2 from the original series is used in almost all of my sound examples here.

With the SSM-based version, obvious clipping can be generated from the control position “3 o’clock” (“Gain” control) with the appropriate input signals. The clippinmg is stronger than with the A-130 / A-131 VCAs. This means that the SSM-based A-132-3 can be used specifically for “coloring” and can actually amplify beyond a factor of 1 (so it is not a “voltage-controlled attenuator” like most other VCAs). On the other hand, it is a bit more difficult to handle if you want to keep it “clean”.

Since the beginning of 2019, a replica of the CEM3360 (as the AS3360 from Alfa) has been available again, so that the current A-132-3 once again correspond to the original, “discolouration-free” version. The CEM/AS-based version can be recognized by the imprint of the amplifier module on the middle of the circuit board:

The original version with the Curtis 3360 (today an identical AS3360), in the module version with an SSM component, an SSM/V2164 is located there.

A “Slim Line” version of the module is the A-130-2, which only requires 4 HP of rack space.

Technical specifications

Width8 HP
Depth50 mm
Power requirements30 mA (+12V) / -30 mA (-12V)