This board replaces the original GR-55 - GK board.

• Adds an AUX IN to connect a standard guitar (not hexaphonic) and a 6-channel SUBSONIC FILTER MODULE.
• The AUX IN is buffered with identical gain and impedance as the GK3's jack input.
• The GK3 and AUX IN can be used simultaneously.
• When using the AUX IN together with the GK3, the GR-55's volume will be adjusted by the GK3's VOLUME knob.
• The AUX IN can also be used without connecting the GK3, in this case the volume of the GR-55 will be set to maximum and must be adjusted by the instrument used.
• The AUX IN/Subsonic filter kit contains 6 subsonic filters (Butterworth 24 dB/Octave active filters) to limit the low-frequency oversensitivity of some semi-acoustic guitars with piezo pickups (e.g., GODIN).
• The AUX IN board uses the same ¼” jack original type as the GR-55.
• The AUX IN board uses the same JRC2068 OPAMP as the GK3.
• Plug and play, simple installation, no welding required

The AUX input WORKS with the following effects:

AMP

MOD

MFX

DELAY

REVERB

CHORUS

EQ

The AUX input DOES NOT WORK with:

PCM TONE 1

PCM TONE 2

MODELING TONE

• The internal GR-55 tuner does not work on the AUX input.
• The subsonic filter is not suitable for use with a bass guitar.

It is also possible to use the AUX input alone with a normal guitar without a GK-3.

The AUX IN/Subsonic filter kit contains 6 subsonic filters (Butterworth 24 dB/Octave active filters) to limit the low-frequency oversensitivity of some semi-acoustic guitars with piezo pickups (e.g., GODIN).