by Robin Vincent | Approximate reading time: 1 Minute
G-Storm 4027 VCO

 ·  Source: G-Storm


G-Storm continues their classic synth adaptations into Eurorack with the 4027 VCO module based on the 4027 oscillators chips found in the ARP 2600 and Odyssey. 


4027 VCO

They’ve already tackled the ARP 2600 filter and recently we saw the XaVCF take on the Oberheim filter and the awesome take on the SH-101 oscillator and filter in the 101-VCO and 101-VCF and they’re just the ones we’ve noticed. The 4027 VCO is an all-analogue sawtooth core oscillator with Sine, Triangle and Pulse waveforms with Pulse-Width Modulation. They’ve worked hard to make it as close to the original as possible using a matching transistor pair, an Interfet premium dual FET, temperature compensated resistors, low ESR styrene oscillation capacitor, 5-NPN monolithic substrate transistor array, precision Tune and Tracking trimmers, and the 70s spec op-amps which are still being offered today. All completely vital for those who know about these things.

Features include:

  • Waveforms: SINE (-4v to 4v), TRIANGLE (-4v to 4v), SAWTOOTH (0 to 6v), PULSE (0-6v) w/ PWM.
  • Three 30mm throw Illuminated Bourns slide pots – Frequency, Fine Tuning, and Pulse Width
  • Three 20mm throw Alpha CV slide pots
  • CV1 input: Wide Frequency Modulation (FM)
  • CV2 input: Reduced Frequency Modulation (Vibrato, FM)
  • Keyboard (KBD) V/Oct input.
  • Multi-turn Trimmers: Tune, Tracking
  • Single-turn Trimmers: TRI Symmetry + DC Offset, SINE Purity + Gain
  • CV Frequency Range: C1 –C8 when Initial Freq. is fully decreased
  • No-Input Freq. Range: 10-550Hz
  • Slim design makes it skiff/boat-friendly.

The layout and front design are very reminiscent of the ARP and I’m really enjoying those illuminated Bourns slide pots.

The 4027 VCO is available now for €245.

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G-Storm 4027 VCO

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