The A-130 Voltage Controlled Amplifier is a (very well-equipped) linear VCA. The “sibling module” A-131 works with exponential characteristics, but is otherwise identically equipped.
It has already been shown with the mixers A-138a (linear) and A-138b (exponential) that an exponential characteristic of the amplification comes closer to our psychophysiological feeling of a “perceived linear” volume control.
Therefore, the linear amplifier A-130 is preferred for control voltages.
User interface
Inputs:
![](https://a100.ideenhase.de/wp-content/uploads/2023/09/NEWCTRL-A130-IN-680x1024.png)
- CV1: Control voltage input for modulating gain (without attenuator).
- CV2: Control voltage input for modulating the gain (with attenuator “CV2”).
- Audio In 1: Input for audio signals or control voltages, which are amplified according to the control voltage at “CV1” and “CV2”.
- Audio In 2: Additional input for audio signals or control voltages, which are amplified according to the control voltage at “CV1” and “CV2”. The module has a small “internal mixer” – luxurious!
Outputs:
![](https://a100.ideenhase.de/wp-content/uploads/2023/09/NEWCTRL-A130-OUT-680x1024.png)
- Audio Out: Output for the amplified signal from “Audio In 1” and “Audio In 2”.
Controls:
![](https://a100.ideenhase.de/wp-content/uploads/2023/09/NEWCTRL-A130-SW-680x1024.png)
- Gain: Manual controller for the gain (setting a continuous level).
- CV2: Attenuator for the control voltage input “CV2”.
- In1: Attenuator for the audio/control voltage input “Audio In 1”.
- In2: Attenuator for the audio/control voltage input “Audio In 2”.
- Out: Attenuator for the “Audio Out” sum output.
Control voltages
![](https://a100.ideenhase.de/wp-content/uploads/2017/09/PATCH-A130-LFOMix-300x266.png)
The module is ideal for amplifying/attenuating control voltages.
If you have several LFOs or LFO and ADSR available, you can easily create more complex modulations.
“Smoother” volume gradients for audio
If you need a slightly less “pointed/jagged” volume curve for audio signals, it’s definitely worth trying a linear VCA instead of the usual exponential variant (like the A-131). Incidentally, the effect of a linear VCA cannot be replaced by longer decay etc. times in the ADSR generator – the two modules behave differently with the same control voltages and thus change the characteristics of the gain curve.
Technical specifications
Width | 8 HP |
Depth | 45 mm |
Power requirements | 20 mA (+12V) / -10 mA (-12V) |