Fusion VCO

EU customers: + VAT for customers in the EU without EU VAT registration number + shipping
Outside EU: + local taxation (VAT / trade tax / import duties) is applicable in the country of delivery + shipping
  • local_shipping Worldwide delivery with UPS/Fedex/Latvian Post
  • account_balance_wallet Pay securely with Credit Card or PayPal
  • beach_access 24 month warranty
Erica Synths Fusion VCO is a special kind of VCO – it fuses the great tuning of a digital VCO with the warm and unique sound of vacuum tubes that work in suboscillator circuit.


  • 3 basic waveforms (sine, triangle and pulse) with VC morphing, for example, triangle morphs from sawtooth to ramp
  • Good 1V/oct tuning for 8 octaves
  • Vacuum tube based suboscillators -1 and -2 oct
  • Manual and CV controlled -1/-2 oct mixing
  • Adjustable suboscillator waveshape
  • Dry/Wet (VCO/suboscillators) mixing
  • Passive Lowpass filter for extreme subbass sound
  • Audio input

This module contains two double triodes in bistable latch connection that act as suboscillators: -1 and -2 octaves with plenty of mixing opportunities for amazing sonic results. External audio signal can replace internal VCO. If you wish to go for really low frequencies and have a sound that sets your modular system apart from others – this is exactly  the module, you need!

All Fusion modules by default are configured to work with regular eurorack PSU.

Due to the fact that cold tube heaters have lower resistance, Fusion modules have significant power consumption peak at startup, when power consumption almost doubles for 1-2 seconds. This is not a problem with linear PSUs that have power inertia, but may cause switching PSU internal protection turn off the power supply. Please make sure your PSU has some headroom before installing multiple Fusion modules.

Would I build a setup around valve modules? I was expecting to say no, but having spent time with the Fusion setup I’m surprised to say I actually would. It’s distinctive, it’s versatile, but more importantly it’s fun. Music has always been about philosophies and aesthetic choices; Erica understand that and offer something fantastically different with the Fusion series. These are not sterile, surgical tools. Far from it. And they’re all the better for that. - Attack Magazine

Technical specifications:

Audio input signal levelup to 20V ptp
Output signal level10V ptp
VCO rangeC1 – C8
Power supplybipolar +-12V , eurorack standard
Power consumptionEurorack PSU configuration: 215 mA @ +12V, 185 mA @ -12V (NB – start-up power consuption for few seconds is +-250 mA)
Module width24HP
Module depth35mm

Erica Fusion VCO on Modulargrid

Manuals book

FAQ question_answer

  • My Fusion VCO’s 1V/Oct input is not tracking incoming CV signals correctly, it tracks only the highest notes from the sequencer/keyboard. What should I do?
    If the VCO tracks notes only above C4 or higher, please, make sure that the FREQUENCY knob is all way counter-clockwise, because this knob defines the lowest frequency you can get from the VCO.
  • My Fusion VCO’s 1V/Oct input is not tracking incoming CV signals correctly, it tracks only the highest notes from the sequencer/keyboard, but sounds which come from the VCO are pretty low. What should I do?
    Please, make sure if your device’s output signal is unipolar (from 0V to +10V) because the Fusion VCO’s 1V/Oct input is intended to track only positive CV signals. In case your device has a bipolar output signal (from -5V to +5V), we recommend you to use the Pico MScale: the upper part of this module adds +5V offset, so the signal from sequencer, which gives values from -5V to +5V for 1V/Oct, transforms into a signal which is compatible to the Fusion VCO.