The GRX4 Guitar Router/Switcher provides four (mono) MIDI controlled audio loops.

Relays with gold-plated contacts are utilized to route the audio signal with absolutely no tone coloration or degradation.

The signal path is configured as a series chain of three audio loops and a fourth audio loop (with its own input and output jacks) that can also be used for mute switching or as an Isolated Control/Switching Function.

Includes the same high quality Op-Amp based buffer circuit that is in our BS2 Buffer/Splitter which is both low-noise and musical. Don’t let other’s try to deceive you, nothing is transparent !!!

The buffer circuit can be bypassed (via an internal switch) for a completely passive signal path.

Buffering prevents the loss of (1) signal level (2) high end frequency response and (3) low end punch that is caused by cable capacitance and/or the poorly designed input stage/circuitry of some FX pedals.

An infinite number of GRX4's can be used simultaneously and/or added to existing rigs with other switchers.

Capable of switching both instrument level (pedals) and line level (rack fx with the buffer bypassed) audio signals.

Compatible with all MIDI footcontrollers and responds to MIDI Program Change messages or Control Change messages.

Powered by a (not included) 9VDC Adapter (we recommend the Boss PSA-100/110/120/220/230 or 240 depending on your local AC supply voltage) with a 5.5mm/2.1mm barrel connector.

Housed in a compact (7.50" x 4.75" x 1.55") and rugged 0.064” thick aluminum enclosure for years of reliable use and performance.

Brushed finish with a black anodized coating and laser-engraved printing.

User Manual (Ver. 2 Rev. 6)

DO NOT USE A COMPACT SWITCHING OR SWITCHMODE POWER ADAPTER (SUCH AS THE BOSS PSA-120S, THE ONE SPOT, THE POWER ALL AND SIMILAR MODELS) TO POWER THE GRX4 BECAUSE THEY HAVE BEEN KNOWN TO DAMAGE IT. A SUITABLE ALTERNATIVE TO THE ADAPTER THAT WE RECOMMEND IS A HIGH QUALITY POWER SUPPLY SUCH AS THE BBE SUPA-CHARGER OR THE VOODOO LAB PEDAL POWER II.