The Doepfer A-133 is a dual voltage-controlled polarizer that functions as a unique kind of VCA—capable of both positive and inverted amplification. This makes it an ideal tool for amplitude modulation (AM), signal inversion, or even basic ring modulation.

Each channel allows manual and CV control over the amplification amount, ranging from -2.5 to +2.5. A dedicated LED visually indicates the current polarity and amount of gain, making it easy to monitor modulation behaviour in real time.

Whether you're shaping CVs, warping audio, or building complex modulation paths, the A-133 offers flexible control with minimal HP.

• Dual voltage-controlled polarizer

• Amplification range: -2.5 to +2.5

• Works with audio and CV signals

• Manual and CV control per channel

• LED shows gain amount and polarity

• Can be used for AM or ring modulation effects