A-133 is a special dual voltage controlled amplifier that enables both positive and negative amplifications. Negative amplification means in this context that the signal is inverted. The main application of the module is the processing of control voltages, e.g. ADSR or LFO but the module can be used also for audio applications (e.g. as a waveshaper, see patch examples below).

The amplification range is about  -2.5....0....+2.5 (other amplification ranges for small additional charges, e.g. -1...+1 or -5...+5). Amplification can be adjusted manually (Man control) and by an external control voltage with attenuator (CV). The present amplification is displayed with two LEDs: one for positive and one for negative amplifications (not a signal display but amplification diplay, similar to A-134).
Another module with polarizing function is the Polarizing Mixer A-138c.

For more detailed information please look at the English user's manual A133_man.pdf