precision adder and active multiple


Description | Specifications | Order online


A 3-input precision adder is combined with a 3-output active precision multiple. The multiple input is normalized to the adder output, so you can have 4 adder outputs total.

Very low gain and offset error make this a perfect tool for adding and splitting pitch CVs, but it is also a great general purpose tool. Of course works for audio as well.

A RGB-LED shows the adder output signal (red positive, blue negative) and multiple input (green, positive only)

You can multiply an input by 2 or 3, by patching the multiple outputs to the adder inputs.

Sumtiple is available as a completely assembled and calibrated module, or as DIY kit. The kit has assembled SMD parts and contains all THT parts and front panel. Construction manual as PDF here.

Technical specs


  • Maximum offset 0.2mV, 0.24 cent
  • Gain error of maximum 0.025%
  • Input impedance: 47k
  • Output impedance: <1 Ohm


  • Maxiumum offset: 0.2mV, 0.24 cent
  • Gain error of maximum 0.3mV @10V input = 0.003%
  • Input impedance: 1 Meg
  • output impedance: <1 Ohm

The design uses very low offset opamps and 0.05% resistors to accomplish these specs. In addition to this, the gain of the adder stage is calibrated on each unit.

  • Printed aluminium front panel, 2mm thickness
  • Supply voltage: +-12V and/or +-15V
  • Supply current: +12V: 10mA , -12V: 10mA, 5V: 0mA
  • Dimensions: 3HE, 2HP, 128.5mm x 10mm, Depth: < 35mm (including power connector)
  • Input / output voltage range -10..10V (20 octaves)
  • Weight: 30g

Buy Tubbutec Sumtiple

Tubbutec Webshop, Worldwide