Add 1 - dual precision adder / comparator

Dual Precision Adder/Comparator
The new version of the Add1 module contains two independent precision adders, with respective different functionalities. The provided basic functions and its versality – suitable both for audio and/or CV applications - makes this module to an useful part of any synthesizer equipment.
The 1st circuit (upper one on the panel) consists of an adder with 3 inputs, whereby the 3rd input is equipped with a polarizing level knob for attenuation, slightly amplification and inversion of this input channel. The sum output has a switch for determing the amplification factor (between *0,5, *1,0 or *2,0); an additional red led indicates if the output signal is becoming overdriven.
The 2nd (lower circuit on the panel) has two inputs and an addable voltage source with an amount control knob (level adjustable from 0 - 5V) and inversion/zeroing switch. The output is switchable between sum and comparator mode. In sum mode, it will provide the additioned sum of the two inputs and the generated voltage from the voltage source. In 'Comp' mode, the circuit works as a comparator with a slightly schmitt-trigger-like characteristic. This signal has only two states, low and high (depending on the threshold level), suitable as gate/trigger, squarewave/pulse audio signal etc.. The threshold level is ≈0V, but it can be shifted by using the internal voltage source or by an external signal. An yellow led is indicating the ‘high’ state; or in sum mode, the clipping of the output signal.

• Audio sub-mixing
• High precision CV signal mixing
• Addition, substraction, offset control
• Attenuation, amplification, inversion
• Adjustable voltage source (polarity switchable)
• Comparator mode (with logic level output)
• Signal-to-squarewave/trigger/gate conversion
• LEDs for visual control
  
• Current consumption: ca 10mA
• Width: 6 HP (30,2 x 128,5 mm)
• Depth: ca 30 mm