RC-1324 Bus Converter

RC-1324 Bus Converter

Converts 13-Pin Signals to 24-Pin Format and Expands Synthesizer Controls
The RC-1324 was produced from June 2005 to January 2006.


"I've been a Roland guitar synth user for a little over 20 years, and I've owned almost all of the units from the GR-300 to the virtual guitar units VG8 and 88. The RC-1324 is the unit I've wanted for years! It bridges the gap between 13 and 24 pin devices flawlessly. The build quality is first rate and I swear my GR-700 tracks better with my 13 pin guitar than the 24 pin original. Outstanding; Fripp is gonna flip when he gets this!"
"Keep those Inventions coming...!"
Vernon Reid


Features of the RC-1324:
  • Incorporates circuitry and design concepts by GR-300 authority Mark Smart!
  • Use any Modern Roland-Ready, GK-1, GK-2/GK-2A, GK-3, or RMC equipped guitar to play any Vintage, 24-pin Roland Guitar Synthesizer
  • Complete Vintage 24-Pin Synth Controls recreated on the front panel, including Mode Switch and More!
  • Tested for use with the Roland GR-100, GR-300, GR-700, GM-70, Ibanez MC1 and the Korg Z3
  • Unique Built-In Hex Fuzz adds G-303/G-808 Style Hex Fuzz with Separate Output
  • Front Panel Hex Fuzz Filter Switch for Normal or Bright Tone
  • Works with Roland US-20 Unit Selector for Multiple Synthesizer System
  • Foot Pedal Control over Vibrato/LFO depth replaces difficult-to-use LFO Touch Pads
  • Adapts standard 13-Pin Synth Volume Control for 24-Pin Synth Volume Control, including Synthesizer/Guitar Balance Control
  • Electronically Buffered Outputs for Volume Controls and Modulation
  • 6 Front Panel Control Knobs for 24-Pin String Output Levels
  • Powered by 24-Pin Synthesizer so there is no need for External Power Supply
  • 2-space, Rack mountable Enclosure with Detachable Rack Ears for Rack mount or Table-Top Operation
  • Laser-Etched, CAD Designed Front Panel
The New Link Between Modern and Vintage Roland Guitar Synth Technology:

"Well, I'm really, really happy! The response from the GR-300 is just as I'd imagined. The surprise for me was just how more responsive my old GR-700 has become. I feel inspired, I'll be doing some recording tonight!"

"I'm using an Ibanez Artist fitted with RMC's (functionally similar to your Brian Moore), and a Yamaha SG fitted with a GK2, No problems with either guitar. I'm really looking forward to now integrating my 24-pin synths along with my current 13-pin rig, without the hassle of changing guitars."

"Many thanks Wayne, You will be highly recommend to all my friends and associates."

Jim Bradford



" I'm having a blast! Today I played the RC-1324 and to say it's great is the biggest understatement I've ever made!"

"My Frameworks nylon fretless (!) works just great with it. And I think it even tracks better than before."

" I'm totally satisfied with this thing, so thanks again Wayne - you did a wonderful job. Keep those inventions coming!!!!"

Ulrich Muller


The rare RC-1324 Version 2. A few of the distinct, black-panel units were produced in 2006. The version 2 design adds a variable hex fuzz level control, a modified hex fuzz circuit (for more clarity), and a front panel blue power LED. Version 2 does not have the Pitch Bend control, which only works with the GM-70 and MC1 pitch-to-MIDI processor.
    Roland has produced two very different, incompatible guitar synthesizer technologies, each with their own special qualities. The older, 24-pin technology is known for its rich, lush analog synthesizer sound. These synths were controlled by limited selection of Roland-built guitars, and a few rare third-party guitars, including the Ibanez IMG2010.

    The newer 13-pin technology includes the latest synthesizer advances and new guitar designs including Fender Roland-Ready Strats, gorgeous Brian Moore guitars, Godin Acoustic/Electric guitars, and others. These newer guitars represent the state-of-the-art in guitar technology, with integrated magnetic and piezo pickups for new sounds and playing options unavailable from Vintage Roland guitars.

    Until now, Vintage Roland equipped guitars could play both the new and old technology, using adapters like the BC-13, BX-13, DC-13 or SBC+. But it was not possible for contemporary guitars to play the Vintage synthesizers. In addition to their totally different specifications, modern guitars lack the built-in control voltage knobs and switches needed to operate Vintage synthesizers.

    The RC-1324 Bus Converter is a unique processor that bridges these two technologies. The RC-1324 conditions and adapts 13-pin signals to work with 24-pin synthesizers, and recreates all the possible Control Voltage signals needed to take advantage of Vintage guitar synthesizer systems.


REAR PANEL: 24-Pin Output, Vibrato/LFO CV Pedal Input, and Dedicated Line-Level Hex Fuzz Output
Connecting State-of-the-Art Guitars with Vintage Synthesizer Technology:

    System set-up with the RC-1324 could not be any easier: simply run a 13-pin cable from the Modern guitar controller to the front panel input of the RC-1324. Then, use a 24-pin cable from the rear panel 24-pin output connector to any Vintage Roland guitar synthesizer. Turn the Vintage synthesizer on, turn up the Synth volume on the guitar, and you are ready to play.

Cable in to the Modern guitar synth controller
Cable in to the RC-1324 front panel input
24-pin output from the RC-1324
24-pin cable plugged in the Vintage Roland synth


All Three "Craig Anderton" GR-300 Modifications Built-In:

    In the mid-eighties acclaimed author/musician/electronic arts wizard Craig Anderton developed three modifications for the GR-300. Unfortunately, these very popular modifications involved making physical changes to the GR-300 or GR Controller. The RC-1324 actually incorporates all these modifications, without having to alter your precious, Vintage GR-300 in any way!
Improving Hex Fuzz High-Frequency Response
Craig’s first modification involved opening up the Guitar Controller, a G-303/G-505/G-808 and cutting a capacitor to add high-frequency response to the Hex Fuzz circuit. The RC-1324 has a front panel filter switch to select between classic Hex fuzz tone, and a brighter, edgier Hex fuzz sound.
Filter Switch down for classic G-303/808 fuzz, or up for a brighter sound.
Separate Hex Fuzz Out
Next Craig designed a separate Hex Fuzz output. However, this modification also involved working inside the GR-300, and disabling either an existing jack, or drilling holes for additional output jacks. The RC-1324 has the Hex Fuzz output built-in, so no drilling or modification is necessary. And the Hex Fuzz sound is always available, regardless of what kind of synth is used, and independent of the volume controls.
The RC-1324 has a rear panel Hex Fuzz output.
Vibrato Pedal
The final Anderton modification is the addition of a vibrato, or LFO pedal. Craig disliked using the touch plates on the GR guitars, and felt a pedal worked better. Ask any Vintage guitar synth player: these controls were very unreliable. By using a Korg/Yamaha CV pedal you can have foot pedal control over vibrato. And again, this requires no drilling or modifications in any way to your Vintage Roland synth.
Use a CV Pedal or front panel LFO knob to control Vibrato/LFO depth
Easy Access to Individual String Level Adjustments:

    The weakest parts of the Vintage Roland guitar synth were the tiny, internal trim pots used to adjust the output of each string. These were the parts on the guitar most likely break over time, and proper string level adjustment is particularly critical for Roland GR-700, GM-70 and Ibanez MC1 users. The slightest change can cause one string to suddenly be louder, or can cause strings to track poorly. You will notice that modern 13-pin synths incorporate string level adjustments in the synthesizers, so there are no level adjustment controls on the guitars. The RC-1324 has six dedicated control knobs to precisely adjust the level of each string for precise, even tracking. And, the RC-1324 lets you do something you could never do with a Vintage Roland controller: adjust the output levels while you are playing!
The original Roland tiny internal trim pots were fragile and difficult use.
The RC-1324 front panel knobs make level adjustment easy.
Proper string level is critical for the GM-70, MC-1 and GR-700.
Audio and Video Samples of the RC-1324:

Below are some examples of using the RC-1324 with various combinations of gear. The only outboard effects used were some chorus and delay.

RC-1324 V2 with Roland GR-300, GR-700, US-2 and Parker Nitefly SA
A Parker Nitefly with factory Roland MIDI GK pickup installed drives a Roland GR-300 and GR-700 with a Roland US-2.
RC-1324 V2 Hex Fuzz Demo with Roland GR-300 and Parker Nitefly SA
A Parker Nitefly with factory Roland MIDI GK pickup installed drives a Roland GR-300. This video highlights the RC-1324 V2 hex fuzz sound.
RC-1324 with Roland VG-88, GR-300, US-20 and Godin Multiac Steel SA
A Godin Multiac Steel SA guitar is used with the RC-1324 to drive a VG-88 and GR-300. Guitar quotes from "First Circle" and "Travels" by Pat Metheny and Lyle Mays
RC-1324 with Roland GR-300 and Godin ACS-SA Guitar
A Godin ACS-SA Slim Nylon Multiac guitar is used with the RC-1324 to drive a GR-300. Apologies to Pat Metheny and Sting!
RC-1324 with Roland GR-700 and Brian Moore i2.13 Guitar
A Brian Moore i2.13 guitar is used with the RC-1324 to drive a GR-700. The Filter knob is used to edit the cutoff frequency, and the Resonance knob is used to edit the pitch range of DCO 1.
RC-1324 Fuzz Hex with Loops and Synth Bass
Direct output of the RC-1324 Hex Fuzz guitar tone, played by a Brian Moore i2.13 guitar, and recorded directly into Digital Performer. Stylus RMX provided the loops, and Atmosphere the bass. The RC-1324 internal hex fuzz alone produces a Vintage Roland Guitar Synth-like tone, without the guitar synthesizer!
RC-1324 Hex Fuzz with G-303 Normal Filter
Direct output of the RC-1324 Hex Fuzz circuit with the darker, G-303-style filter engaged. Note the exceptional, 30 second decay of the last chord. Because of the extra gain stage, the RC-1324 Hex Fuzz has an exceptionally long sustain.
RC-1324 Hex Fuzz with G-303 Bright Filter
Direct output of the RC-1324 Hex Fuzz circuit with the front panel filter switch in the "up" position. This is a brighter tone, and recreates the Craig Anderton G-303 filter modification.



Frequently Asked Questions:

  • Does the RC-13 add any latency or delay?


    • NO! None of my processors add any delay at all. Like the GR-300 and GR-100, they are purely analog processors that do not suffer from the inevitable latency introduced by digital systems. Many players notice that their guitar synths actually play better, since the gain stages have been especially designed to deliver the best possible signal to the guitar synthesizer.

  • Will the RC-1324 work with ANY Vintage Roland Guitar Synthesizer?


    • YES! I have tested this with the Roland GR-100, GR-300, GR-700, GM-70, Ibanez MC1 and the hard-to-find Korg Z3. In each case, the Vintage Roland synthesizer worked just as if a Vintage guitar synthesizer was plugged in. You can tweak sounds, edit patches, and control the synthesizer in real-time using the CV knobs or CV pedal.

  • Will the RC-1324 work with ANY Modern Roland-compatible guitar synth controller?


    • YES! However, due to the huge variety of guitars currently available in the 13-pin format, I have not been able to begin to test them all. My primary test guitar was the Brian Moore i2.13 guitar shown in the photos, a Godin ACS guitar, and a GK-2 equipped custom Telecaster.

  • I want to play my GR-300 and my GI-20 at the same time. Is this possible? Can I use a Roland US-20 with the RC-1324?


    • YES! I have tested the RC-1324 with a Roland US-20, and it works great! Until now, the only way to play a Vintage and Modern Synth at the same time was with a Roland US-2 and BX-13/BC-13/DC-13 or with a SBC+. Now, just plug your Modern guitar into a Roland US-20, and take one output to the RC-1324 and the other output to any Modern Roland synth. In this case the volume knob on the guitar will control the volume of both the Vintage, 24-pin synthesizer and the Modern, 13-pin synthesizer.

    Please note, the Roland VG-88 V-Guitar System does not play as nicely as other Roland Guitar Synthesizers or Pitch-to-MIDI converters. In certain cases, the VG-88 used with other equipment will add some low-level noise. This issue is much less significant with other Roland GR gear, though ground loops can easily occur with any multiple synth system. You can read more about this at the Yahoo GR-30 Group. Do a search for the thread GR-30 and VG-88.

  • Can I create the classic "Pat Metheny" GR-300 sound with different guitars? Pat always uses a Roland G-303.


    • YES! I have tested the RC-1324 with a Roland GR-300, and it works just like a flawlessly, with the same incredible tracking the GR-300 is known for. If you check out the demos page on my GR-300 website, you can find examples of the classic "Pat Metheny" GR-300 sound created with a Roland G-707 or Ibanez IMG-2010. The controller is not that important. And the video clip above shows a Godin ACS guitar creating the "Pat Metheny" GR-300 sound. The only difference I noticed was the decay of the sound. Obviously, a Nylon acoustic guitar has a much different decay than an electric guitar.

  • How does the Hex Fuzz on the RC-1324 compare with the Roland Hex Fuzz?


    • The Hex Fuzz circuit in the RC-1324 is unique. While the filtering stages are designed to copy the sound of the Roland G-303/G-808 Hex Fuzz, an additional gain stage has been added for a harder edged fuzz circuit with a lot more sustain. The front panel bright switch is designed to reproduce the effects of removing the filter capacitor from a G-303/G-808 guitar to produce a brighter fuzz tone.

  • What kind of CV pedal is required for the Vibrato/LFO depth?


    • Any Korg or Yamaha CV pedal will work. Or any pedal that is compatible with the Korg/Yamaha standard will work equally well. The Korg/Yamaha pedal uses a 50K potentiometer, with the wiper wired to the ring output. Unfortunately the Roland EV-5 will not work with the RC-1324, since it uses a 10K potentiometer, and has the wiper wired to the tip output.

  • Do I need a CV pedal to use the Vibrato/LFO feature?


    • NO! You can simply use the front panel LFO knob to control Vibrato/LFO depth. But the CV pedal is mighty useful for "hands-free" operation.

  • What is the range of the CV pedal?


    • The CV pedal controls up to 100% of the value of the respective front panel LFO knob. So, if the front panel LFO knob is set to 40%, then plugging in the CV pedal and turning it all the way up will result in a modulation depth of 40%. Actually, this works GREAT for things like modulation, where you may only want a little to flavor the sound. Set the front panel knob to the desired maximum output, then use the pedal to gradually ease to effect in and out.

  • I have never heard of Pitch Bend on vintage Roland guitar synths before. Where do I find this feature?


    • Only on the Roland GM-70 or Ibanez MC-1. Clearly, Roland had special plans for Pitch Bend, or CV#3, but it was only Ibanez who built a controller that used Pitch Bend, the excellent IMG2010. The GM-70 works with Pitch Bend, and CV#3 is noted as "pitch bend" in the GR-700 service manual, but this feature is not actually wired to the circuit board. With a GM-70 or MC1, the Pitch Bend knob can be assigned to any kind of MIDI message, Pitch Bend, reverb level, etc.

  • Is this unit for sale? Yes! A complete RC-1324 sells for $1999.


    • The price also includes a one year warranty on parts and labor. Email me if you are interested, and I can let you know the availability of a new RC-1324.

  • Where do you get the connectors? I thought they were discontinued by Roland a long time ago.


    • YES! Roland discontinued the connectors from active production about fifteen years ago. So the 24 pin connectors are virtually impossible to find. I bought as many of these connectors as I could from Roland a while back. Depending on availability, I also use connectors refurbished vintage guitars and synths. Either way, there is no new supply of these connectors, so all the processors I build have a very, very limited production run.

  • Who is that Mark Smart guy you mentioned at the top of the web page?


    • Mark Smart is a brilliant musician/engineer/innovator who has been kind enough to help me with my guitar synthesizer projects, and let me use some of his cool circuit designs in the RC-1324. Mark is fluent on guitar, Chapman stick, and a radical new controller, the Haken Continuum Fingerboard controller. In addition to his one-man jazz guitar gigs, Mark is also a demonstrator for the Haken Continuum Fingerboard.


Click to download RC-1324 Owner’s Manual

Click to download RC-1324 V2 Owner’s Manual
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