ADDAC216 Sum & Difference – Full DIY Kit

£109.00 (Excl. VAT)

Utility mixer with dual sum & difference options

Out of stock

You must register to use the waitlist feature. Please login or create an account
SKU: Kit_ADDAC216_Sum_Difference Categories: , , , , Brand: HP Size: 8 HP


The ADDAC Sum & Difference features two equal sections labeled A and B. This module is a peculiar type of mixer that instead of just summing two input signals (X & Y) also allows the possibility to subtract the two signals.
It works both for audio and CV signals so there is the possibility to get the difference of two CVs or cancel the phase of two audio signals. The resulting signal, of sum or subtraction, is then routed through a switchable (on/off) full rectification circuit labeled: Absolute. After this the gain of the mixed signal goes through another attenuverter labeled: Amplitude – to control the resulting signal gain and add the possibility to invert the incoming signal. After the Amplitude comes an AC/DC coupling switch followed by a bipolar Offset knob.

As well as the normal outputs there’s also an inverted output for each of the A & B sections.
The outputs of section A & B are also summed and sent to the Average Output.

When using a single input (just the X or Y input) the module can also be used as a simple dual Attenuverter & Offset CV processor with full rectification and AC coupling options.

ADDAC216 – Assembly guide | User guide | Signal Flow Diagram


  • 2 independent sections each with:
    • 2 inputs with gain attenuverters
    • Amplitude attenuverter and bipolar Offset
    • Absolute/Bipolar and AC/DC switches
    • Output and inverted output
    • 2 leds monitor the output polarities and gain.
  • Average mix output of both sections
  • Width: 8HP

Additional information

Weight 0.1278 kg
HP Size