Bill Bax GK13 Breakout box - anyone see this?

Started by aliensporebomb, September 29, 2009, 07:19:29 AM

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Hi Guys,

Thanks a lot for your comments on the article.

Musican65...appreciate you thoughts with a GK pickup output connector, the new FTP and a breakout box.  Ah, this sounds like a lot of R&D, and would expect Elantric and Gumtown to have a digital edge on me here.  I've been keeping up to date on their radio GK device, and have say I'm impressed with the follow-through shown.



Bill Bax has a new Breakout Box



Passive breakout box with 3/5 of a Roland GKP-4 distribution box capability.  A GK Hex pickup can control two separate v-synths, and record/play separate strings simultaneously.


GK IN (Left Connector), GK OUT (GK Power) Centre Connector, GK OUT (SYNTH 2) Right Connector.

SWITCHES: Four LED switches: Two patch selector switches.
Two volume selector switches. GKP-4 distribution type operation.
Three TRS stereo 6.35mm separate string outputs (E, A, D, G, B, E).   
Three TRS stereo 6.35mm jacks separate string line-level inputs for
v-synth re-amping from a DAW or multi-track.
Two 'normal' guitar' Pin-7 I/O 6.35mm jack sockets.  'Pin-7 IN' is a 'switch-jack' and inserts a mono line-input from a DAW etc.
90dB with a separate string output (Roland GK-3 typically).
Separate string Total-harmonic-distortion  = 0.00550% or better. Hex pickup/preamp dependent.   
String cross-talk is hex pickup dependent, although separate string separation is generally around 35-40dB, but can go as low as 7-10dB depending on playing technique and relative notes played.
Length 153mm.  Depth 84mm. Height 52mm.
Approximately 700g.
DC-offset, normalize, noise-gate, re-tune, reverse, volume, cut, split, copy, paste, move, delete etc.

GUITAR AND PICKUP SELECT: Stratocaster -Les Paul -Telecaster-Acoustic etc.
RE-AMPING: Change amp, adjust amp controls, change speaker cabinet, adjust microphone/placement etc.
EFFECTS: Change effects, adjust controls, change effects sequence etc.


Thanks Elantric for spotting this.

My regular UK 13-pin chassis socket supplier is unavailable. Any other supplier suggestions?




This looks really good, as in, I'm putting it on my wish list so when the Mrs. wants a gift idea, there it'll be. Do you think it likely I'd be able to get the whole package (all necessary cables) from you in November or December?



Hi admsustainiac,

Thanks for this. Already have quite a stock of the standard 13-pin pcb socket.  I'm looking for the chassis type.

Thanks again,



Suggest contact Gumbo and his Synth-Lynx) jack

He has a custom "crimped" Female DIN 13 Chassis mount socket that promotes improved electrical Ground contact wit the DIN 13 GK cable


Hi mooncaine,

QuoteI'm putting it on my wish list so when the Mrs. wants a gift idea, there it'll be. Do you think it likely I'd be able to get the whole package (all necessary cables) from you in November or December?

I might be able to manage that, but enjoy spending a long time putting something together. A 2-3 week turnaround in construction and tweaking is about right.



Hi Elantric,

Yes, did think of Gumbo, although I only need the standard plain 13-Pin chassis version.  Just putting feelers out at the moment.




Thanks Elantric,

The first link looks positive and the second is my normal supplier, but they're not trading at the moment (Summer holidays perhaps).




Hi All,

The animated gif was ok, but the new GKP-2 gallery is more explicit.

GKP-2 v-guitar breakout box (low resolution).

Front view blue leds


GKP-2 & cables..."too many cables"'s analog, and they safely plug into almost any audio input/output...

GKP-2 rear




Hi Everyone,

Here is the latest variant added to my re-amping breakout box range. I will try to keep this post short and sweet, as it is easy to rattle on with unnecessary detail.

Front view - Rugged die-cast aluminium case in a red powder-paint finish.  B+W labels.

Rear view - Six Separate Strings I/O. Pin-7 normal guitar I/O (side panels).

Raw GKP-2 on my workbench.  If you think the above pics looks a little photoshopped, then you are probably correct! Here is a more organic looking pic with very little software enhancements. In many ways the image is more pleasing to the eye.

Last 2014 GR-55 re-amping movie, for v-guitarists who are unaware of the universal possibilities with recording and playing separate strings.  Cheesy naff song btw.

Thanks for viewing.



Hi Bill, I was wondering if the gkp2 breakout box will mess with some of the vg99 patches in the same way that the roland us20 does?

Reason I ask is I'm considering a breakout box for use with the sonicsmith converter+ (possibly with 6 of those) and would also like to at least pass on the 13 pin to the vg99.


Hi Chrish,

Not sure what you mean by,
Quote"mess with some of the vg99 patches in the same way that the roland us20 does?"

My passive GKP-1/2 breakout box units are 'thru' from GK IN to v-synth (via six separate string insert switch-jacks), and there is no drop in GK levels. Both units will output separate strings into a sonicsmith converter+ and don't see any problem.

GKP-2 Breakout Box - it's a separate strings hub / telephone-exchange :D

If you're not so interested breakout box separate strings re-amping, you could go for a budget Mini Breakout cable and a Roland GKP-2 cable, linking them up...

GK guitar > Roland GKP-2 13Pin inline socket.  Roland GKP-2 13Pin power cable > VG99 for GK power.  2nd Roland GKP-2 13Pin cable > Mini Breakout cable 13pin line-socket, and then separate strings out to a sonicsmith converter+.  This configuration allows GK separate strings access, GK thru to your VG99, and an inexpensive solution.

Roland GKP-2 cable.

Versatile GK Mini Breakout Cable.

Breakout cable and poly-distortion demo. GK Separate strings can also drive multiple daw sequencer synth plugins at little or no cost.

sonicsmith converter+ (possibly with 6 of those)
Wow, that could get expensive!

Hope this helps,



Quote: "Not sure what you mean by,"

The roland US20 suffers from a flaw, maybe by splitting the 13 pin signal and loading the hex pickup (?). The problem manifests itself by degrading some of the patches like the gr300 model when the US20 is connected to the vg99. 

Steve actually pointed this out to me when I reported problems with certain vg99 models suffering from lack of sustain and quickly fading out into digital dirt.

As soon as I removed the US20 from the signal path, those vg99 models behaved and sounded normally.

I believe a loss of signal gain also happens with the 24 pin splitter, the US2, when the hex pup output is split and connected to a GR100 and GR300.

I'm liking that gear you make. I tried using the breakout box on the Spicetone 6appeal into the converter+ with poor results. I was getting to much noise from even the clean setting on the 6appeal and the converter+ needs a clean signal to help with accurate pitch tracking.

I'm guessing your new hex preamp breakout would work great, but I would also need to a 13 pin through.

You are correct, it does add up but the converter+ ACO tracks extremely well with guitar and is the key to the elusive modern 6 note analog poly guitar synth.

The ACO produces two, pitch stable and very good quality sounding waveforms.


Hi chrish,

There are quite a few permutations with your desired GK preamp separate strings to sonicsmith convertor+ setup, and maybe we should go the email route wrestling with options. We can always report back to the forum later with results and conclusions if you prefer. 

I think your GK preamp to sonicsmith solution is a combination, and the minimum cost solution is a Roland GKP-2 cable and my Mini Breakout cable linked.

You mention my GK Extreme preamp with 'separate strings out' as a strong option.  It would be fairly simple to add a 13pin socket to the GK Preamp case, feeding your VG99 and separate strings out, although my only concern is the overall costs involved.

Also you mentioned a 'loading' effect with the US20. I'm not sure if this is always the case with routing 'strings out' > effects and VG99 Thru. In some instances 'Strings-Out' and GK-Thru only requires a v-synth +/- sensitivity compensation adjustment / new profile.

Another option could be GP10 > USB > DAW > Asio4all > DAW Interface > Strings out > Sonicsmith convertor+   

Is your GK to sonicsmith convertor+ for live or studio setup, or both?




Quote from: billbax on April 28, 2019, 05:37:11 PM

Is your GK to sonicsmith convertor+ for live or studio setup, or both?

I would be using that setup in the studio. If I ever did perform live again, I would use the VG99 or the Sy300 for synth and bass because it is so simple to set up.

Thanks for the information. I'll need to read your web site when I get more interweb data in a few days, otherwise I can't get the click on stuff to load.


Hi everyone,

Here's a look at the latest GKP-1&2 breakout box units. I'll try to keep it brief, and let the photos do the talking.

What's new:

Modified 13-pin panel-mount sockets with 360-degree four-point ground shell contacts, including positive individual pin 'grip' insert contacts 1-13.
It's an audiophile 13-pin socket component with three GKP-1&2 enclosure ground contacts, and five 13-pin plug > GKP-1&2 socket ground contacts - the ground cannot lift!
Finally, the front panel features smaller GK function switch LED buttons - no more lighthouse large button glare.

GKP-1&2 Rear separate strings I/O.  Strings 'IN' are switch-jack inserts for 100% separate string control 1-6.
Strings 'OUT' are hardwired 'OUT' for independent separate string connections.

Pin-7 buffered 'normal' guitar input module, allows a GK guitar and a 'normal' guitar simultaneously (GR-55 use typically).

Pin-7 TRS outputs with GK preamp/pickup direct out, and Pin-7 'normal' guitar input module output. Covering all guitar and separate strings I/O permutations.

On the bench raw photos

* Free 30-Pack of 13-Pin plug and socket dust covers with every order...of course.

Thanks for viewing,


GKP-2 Breakout Box and SOS Magazine review by Paul White


I ordered a GKP-2 Breakout Box from Bill earlier this year and have now been enjoying playing with it for a few months and wanted to share my experience with other synth guitar enthusiasts;

I actually bought this box as a break-in device so that I could adapt the separate string outputs of my Gibson HD.6X-PRO hex equipped guitar to use with Roland 13-pin equipment (such as my GR55) and it has done this job marvelously.

Being able to drive two 13-pin pedals has been especially fun (blending tones from the Boss Wave Processor and Boss Poly Octave routed to their own amplifier sounds massive), and I have found that tracking has worked as well as external GK-3 pickups directly connected to individual devices.

The GKP-2 itself is built robustly and I can't see myself having any issues with it any time soon, chatting with Bill before and after my order was super easy and he answered all the questions I had around my rather specific requirements, I can highly recommend this product and thank Bill for all his help!


Thanks tonesforchris for the GKP-2 breakout box review. I remember you emailing a few Gibson HD.6X-PRO breakout box output .wav files, and immediately knew we would have success connecting up your GR-55. You showed great patience, when most folks would have given up.


GKP-2 P7 normal guitar input rant...oh no :-X

GKP-2 Buffer module. Achieving a quiet normal guitar P7 input is a battle, and a 1/4 jack sized pcb is the solution. The 10K input resistor and short pcb track length to pin-3 op-amp is critical. Add a metal enclosure to the circuit, dual-screened guitar cable, and you have a 14dB EMI noise-floor improvement compared to GK3.

High-Gain patch horror exposes normal-guitar inputs. The test is simple by dialling down your normal guitar volume to 8.5. If your guitar hum increases, there is a problem.

Make yourself a short dual-screened GK3 cable. A 2-3dB improvement doesn't sound much, but it helps you sleep at night :D