Black VCO Expander

£119.00 (£99.17 ex VAT)

Expander for the Erica Synths Black VCO & VCO v2, adding an advanced waveform mixer plus a 2-octaves-down suboscillator with colour control.

Out of stock

Join the waitlist to be emailed when this product becomes available

SKU: black-vco-expander Categories: , , ,


The Erica Synths Black VCO Expander essentially is an advanced waveform mixer for their BLACK VCO or BLACK VCO 2, which also adds a whole host of other useful features, including: A transistor-based -2 OCT suboscillator with colour control (a lowpass filter); an additional waveform, similar to a folded sinewave and accessible via a three-way switch (along with Triangle and Sine); plus 3 different outputs (Full mix, Sub Mix only, and -2 OCT Sub only)

It allows you to explore beefy analogue wave design in brand new areas.

Matttech note:If you have the BLACK VCO 2, you will know that it already offers a -1 OCT sub output (one octave down from the main VCO frequency/pitch). By adding the Black VCO Expander you will be able to simultaneously access a second Suboctave at -2 OCT, and you will not only have front panel control over the level of your SUB in general, but also the blend of -1 OCT and -2 OCT versions.
Having many, many times patched up multiple outputs of an analogue VCO into a mixer in order to achieve this kind of thing, and found myself jamming with the levels and octave switch of the various waves and sub whilst recording, I can attest to this being an EXTREMELY useful feature! It not only saves you the bother of patching – and reduces cable spaghetti – but actively encourages live tweaking to a deeper level.

It is also a sensible idea to have switch for sine and triangle, as you’d rarely – if ever – use both at once …and the addition of the SUB COLOUR is another masterstroke, as you can essentially remove the high frequency content from your SUB, making it more like a Triangle or Sine SUB, which can often be a lot more usable in a dense mix. Great idea!


  • Waveform mixer/inverter
  • 3-wave waveform switch to switch between Sine, Triangle and….
  • …a 3rd new waveform added by this expander called”Tits” (Their words, not ours. “Bum” would be an equally suitable name, once you’ve seen it on a scope). It is similar is shape/ sound to a wavefolded-sinewave.
  • A transistor-based -2 octave suboscillator
  • -1 and -2 octave suboscillator crossfade control
  • Suboscillator Mix level control
  • Suboscillator lowpass filter
  • Diode limiter on output signal amplitude
  • Three simultaneous outputs – Full mix, Sub Mix only, and -2 OCT Sub only.

NB! This expander module can be connected only to Black VCO and Black VCO2. It will not work as a standalone Eurorack module.

Width: 18hp
Depth: 30mm
Power: See BLACK VCO 2 Product Page

…and here shown with the BLACK VCO (v1)