GSO-01 / GSO-02 (Geo-Synchronous Orbiter) Eurorack Module & Expander

Designed in collaboration with Holy Island Audio

GSO-01 (or Geo-Synchronous Orbiter for short!) is a voltage controlled FX pedal loop + feedbacker for eurorack with on board DC jack for powering the pedals that you're using in the loop. Along with the knobs it also offers CV control over wet/dry mix, feedback and voltage starve for the onboard DC supply

The optional GSO-02 expression expander further expands the flexibility of the module by allowing external expression controllers to manipulate any of the feedback, mix or power starve controls. The GSO-02 expander is passive and connects to the rear of the GSO-01 with a supplied cable, this means it doesn't take up any of your precious power supply spots!

CONTROLS:

Feedback

Turning this control up will increase the amount of signal that is fed from the return jack of the effects loop back into the send. With nothing plugged into the send, return or crossfade jacks, the signal present at the input socket will be fed back upon itself to produce more complex waveforms. This can also be modulated via the linked CV input, the knob acts as an offset.

Mix

Balance between the dry input signal (anti-clockwise) and the wet effect & feedback line (clockwise). This can also be modulated via the linked CV input, the knob acts as an offset.

Volts

Determines the output voltage of the adjacent DC jack to allow for voltage starving effects pedals. This will output between 0-9VDC (centre-negative) to a pedal connected to this socket. Voltage from this output is limited to a maximum of 9V to maintain a safe level for use with guitar effects pedals.

This voltage can be modulated via the linked CV input,
the knob acts as an offset.

When using CV to modulate the voltage being sent to an effect that uses electronic switching (e.g. Boss pedals, or any pedal with a soft touch relay system), it’s important to add an offset voltage by using the Volts knob to ensure that at the lowest point of the modulation the voltage doesn’t drop below the level at which the pedal resets.

Phase toggle

This toggle allows for the signal’s phase to be reversed at two points in the circuit, each setting will behave differently depending on what you have patched into the effects loop. Listen to the output of the module and flick through the three switch positions to see what sounds best for your application. Refer to the block diagram for more clarification on the behaviour of this toggle.

Send Jack

Connect this jack to the input of the effects pedal in the loop. Signal sent from the input socket is attenuated to match the level a typical guitar pedal is expecting.

Return Jack

Connect this jack to the output of the effects pedal in the loop. The returning signal is amplified back to a modular level.

Crossfade Input

The 3.5mm jack linked via the artwork to the return jack is designed to accept a modular level signal. It can be used to crossfade between a modular level signal and the input signal. Using this input without anything patched into the main input will allow the module to be used as a VCA.

Width : 8HP
Depth : 44mm
Power Consumption : 50 mA +12V/ 30 mA -12V

Also included with the GSO-01:
- Ribbon cable to power power the module
- 2.1mm barrel DC cable to power up your effects pedal
- Assorted Holy Island & Life Is Unfair loot (Stickers/blank panels)