Roland GR-300 Remote Control Box


Custom built Roland GR-300 Remote Control Pedal	Custom built Roland GR-300 Filter Preset Pedal

This Control Box for the GR-300 provides:

Two filter presets (preset one and preset two)

Switch to enable external filter pedal control

Foot Switch for GR-300 Compression feature

Foot Switch for GR-300 Pitch Sweep

Foot Switch for GR-300 String Select

Big LEDs to look cool on stage!

Elegant Design

Filter Presets and Pedal Control:


FILTER CONTROL SCHEMATIC	PRESET 1 and PRESET 2	PRESET 1 and PRESET 2

The GR-300 has many cool features that few players use, like compression or pitch sweep, mainly because these functions work best with a foot switch. The pitch sweep feature is dramatic, but it is not the kind of thing you want to hear every time you engage the pitch presets. The GR-300 remote puts controls for these features, plus filter presets, in one box.

After I built the original Remote Control Box, I built a newer unit to only select presets for the GR-300. This Filter Preset unit was built to match the same design as the BX-13 V2 and V3. Otherwise, it works exactly the same as the original Remote Control Box. I really liked playing with the filter control, and enjoyed using the pedal for some cool filter sweeps. I also tried some different pots. Why different values? In critical listening tests, the 100K pot opened the filter up slightly more, but the 50K pot yielded the most useable range. If you are building for musicality, I would keep both pots at 50K.

Foot Switch 1, marked "preset" selects between filter preset 1 or preset 2. Foot Switch 2, marked "pedal" selects between the preset knobs and the pedal. There are LEDs associated with each knob so you can know which filter knob is active, even when the pedal is on.

Also, keep in mind that the amount of filter control depends on the filter control setting on the GR series controller, or the GK-1. The control knobs, or the pedal, make the sound of the GR-300 brighter. Therefore, if you want maximum range, set the filter control on the guitar to minimum.


Interior of Remote Control	Interior of Preset Pedal

NEW! Video Demos of the GR-300 Remote Filter Pedal:

The Remote Filter Control Box in Action!


The PRESET foot switch toggles between filter setting preset one and preset two. Top panel LEDs show which filter setting is active. In this picture, preset one is active.	The PRESET foot switch toggles between filter setting preset one and preset two. Top panel LEDs show which filter setting is active. In this picture, preset two is active.	The PEDAL foot switch toggles between the filter presets, and an optional foot pedal for foot controlled filter sweeps. In this picture, the Pedal is active.

LFO Control:

An earlier version of this box included LFO control. This presented two problems: one, the GR-300 does not have a LFO input, and there is no way to make the LFO feature function without opening up the GR-300 and performing the modifications outlined in the Craig Anderton GR-300 modification article. I was able to successfully modify my own GR-300 without any problems, and liked this design. After I sold the Version 1.0 unit on ebay, I received quite a few emails from people who had broken the plastic ribbon connectors inside their GR-300. After twenty years, the plastic has become very brittle, and is prone to breaking. Furthermore, not many users wanted to drill a new hole in their GR-300. So, I cleaned up this design, and eliminated the LFO control.

Standard GR-300 Foot Switches:

Finally, I mounted three SPST foot switches and wired them to standard 1/4 inch output jacks to control compression, VCO pitch sweep, and string select. Though, as a GK-1 user, I had to modify the GK-1 to make the string select foot switch work! You would be surprised at how having these foot switches can change the way you play the GR-300. I would never use the Pitch Sweep function before, but now that I can engage the feature when I need it, I find I am more apt to use this cool GR-300 function.

Finally, I had to hunt down a control pedal to use with this unit. Version 1.0 was designed around a Korg EXP-1. These pedals work great, but are curiously hard to find, and are the most expensive control voltage pedals on the market. I recommend the MPM VP 26-U, which is a genius design that has a dual potentiometer inside. This means you can you use it in "Korg" mode, with the 40K pot (very similar in value to the 50K pot used for preset one). Or you can use it in "Roland" mode, where it functions like a Roland EV-5 (10K potentiometer). The wiring also changes slightly. In Korg mode, the ring is the wiper, and in Roland mode, the tip is the wiper. Unfortunately, these are also getting a little hard to find, since it seems they have been replaced by the MPM VP 26-P.