NickLabs Posted May 28, 2008 Report Share Posted May 28, 2008 Hey, I am currently building my second electric guitar and was planning to include in the build a internal roland GK midi pickup kit to fit my guitar synth. Unfortunately during the build i have ended up not leaving enough room between the tremolo and bridge pickup. I have been looking at the graph tech ghost piezo saddles as an alternative but the preamps for these are a bit out of my price range. My question is, as the gk kit is considerably cheaper than the preamp, would i be able to (relatively easily) rewire the gk kit so the pickup used is the grahptech system rather than the roland one provided? Thanks, Nick Quote Link to comment Share on other sites More sharing options...
KeithHowell Posted May 29, 2008 Report Share Posted May 29, 2008 Without looking at circuit diagrams for both systems it is difficult to say categorically, but is the GK system pickup also piezo based or magnetic? If it is magnetic I would say "no not easily" as the piezo preamp will be optimised for a piezo, with around 1M ohm input impedance and to equalise for the piezo signal whereas the GK would be designed for, probably, a low impedance magnetic pickup and be equalised for the magnetic signal. Why dont you just mount the GK pickup in front of the bridge pickup? Or build your own piezo preamp! There are a lot of designs available, just do a Google search. The components will only cost a few $. Hope that helps. Keith Quote Link to comment Share on other sites More sharing options...
NickLabs Posted May 29, 2008 Author Report Share Posted May 29, 2008 Hey, thanks for your advice! Mounting it between the bridge and treble could be an option although i would not like to go for that as is is recommended in the manual to put the gk pickup close to the tremolo. Thinking about it the roland pickup could be magnetic so i shall look into building a piezo pre-amp (for the graph tech saddles), although im not sure about the chances of finding a pre amp circuit with the specific roland 13 pin output, thanks again, Nick Quote Link to comment Share on other sites More sharing options...
KeithHowell Posted May 29, 2008 Report Share Posted May 29, 2008 Your pre-amp only needs to interface the piezo to the INPUT of the Roland device ie where the magnetic pickup would attach on the analog side of the device. It is really just an equalisation unit to interface the different piezo output with the Roland input. Have a look here:Piezo Buffer Keith Quote Link to comment Share on other sites More sharing options...
NickLabs Posted May 30, 2008 Author Report Share Posted May 30, 2008 Oh rite, thats not too bad then. So it would go, Piezo saddle pickups> Piezo buffer> Roland gk pickup preamp > Roland midi pedal? Sorry if im slow lol Thanks for this information, its a great help! Nick Quote Link to comment Share on other sites More sharing options...
KeithHowell Posted June 2, 2008 Report Share Posted June 2, 2008 Yes that would be the way I would do it. However as I said: Without looking at a diagram of the GK unit it a bit difficult to state exactly what you need to do. Does the GK unit have one analog or six analog inputs? My one brush with this type of thing, on a neighbours Casio, had a magnetic pickup with what looked like an analog line per string from the pickup. Just bear in mind that if this is the case you would need to equalise each of the saddles with it's own pre-amp before feeding to the GK unit. Keith Quote Link to comment Share on other sites More sharing options...
dh7892 Posted June 3, 2008 Report Share Posted June 3, 2008 The GK needs seperate signals for each string so you'd have to build a buffer for each string. I'm not really sure what the board for the internal GK pickup does. It might just be routing the wires from the cable or there might some pre-amp stuff going on. If it's just routing then you might want to miss out the GK board all together and wire it up yourself (with your own buffer pre-amps) to the socket (including switches and volume controller). I'm build a guitar at the moment and I'm planing on only having a GK pickup as I use a VG-99. I though about getting the Ghost system as it would look a lot neater having no messy looking GK pickup but they are expensive as you say and I've heard bad things about how the VG-99 sounds with piezo signals. They've put a patch out that's supposed to sound better but I already bought the internal GK kit Quote Link to comment Share on other sites More sharing options...
NickLabs Posted June 20, 2008 Author Report Share Posted June 20, 2008 Hey, Thanks for all the info! dh7892 How wide is the pickup part of the gk kit (How much room minimum is requited between the pickup and the tremolo?) ? Also does anyone know if there is a way of shifting the bridge pickup further up the body when it is already routed without being aesthetically noticable. Bit of a long shot i know but if anyone has any ideas? lol Quote Link to comment Share on other sites More sharing options...
dh7892 Posted June 23, 2008 Report Share Posted June 23, 2008 I'll measure it up when I get home (and when I remember!). But from what I remember, it's pretty narrow. about 6mm or so. (or about 1/16th of an Inch if you prefer). I'll also try to have a look and see if I can work out what the GK circuit is doing. I'd post up some piccies of the board but I don't wanna risk violating any laws or anything. How are your pickups mounted? I'm assuming it's not just a pickguard that you could re-make or anything. Quote Link to comment Share on other sites More sharing options...
NickLabs Posted June 23, 2008 Author Report Share Posted June 23, 2008 If you could do that it would be great, I cant seem to find the circuit schematics anyway and am a bit unwilling to smash open my external pickup! Just mounting the pickups LP style with mounting rings (the part thats going to get in the way i think lol). From rough measurements i have (due to the tremolo bridge cavities size) 4-10mm between the pickup cavity and the edge of the tremolo. However when it is pushed fully back there is no room for the tremolo to move. This is without any pickup rings. I could always modify a black pickup ring by removing the bottom edge and using the gk pickup instead of this edge i suppose! Thanks, Nick Quote Link to comment Share on other sites More sharing options...
Saber Posted June 23, 2008 Report Share Posted June 23, 2008 (edited) I'll also try to have a look and see if I can work out what the GK circuit is doing. I'd post up some piccies of the board but I don't wanna risk violating any laws or anything. A while back, I traced out the circuit of the GK-2A and have a hand-drawn schematic of it. I don't want to violate any copyright or anything by posting it, either. But if someone would PM me an e-mail address, I'd be glad to send a scan of it. Then you could post it or do whatever you want with it. BTW this is how I installed the GK-Kit on my Ibanez 540S. The pickup almost touches the trem. I filed down the pickup ring so I could place the GK pickup over it and have enough clearance between it and the strings. There's another hole in the top from a previous installation of a GK-2A pickup that I took apart so I could install its board internally. And you can see that I replaced the 1/4" jack with the GK jack. Edited June 24, 2008 by Saber Quote Link to comment Share on other sites More sharing options...
dh7892 Posted June 24, 2008 Report Share Posted June 24, 2008 If you could do that it would be great, I cant seem to find the circuit schematics anyway and am a bit unwilling to smash open my external pickup! Just mounting the pickups LP style with mounting rings (the part thats going to get in the way i think lol). From rough measurements i have (due to the tremolo bridge cavities size) 4-10mm between the pickup cavity and the edge of the tremolo. However when it is pushed fully back there is no room for the tremolo to move. This is without any pickup rings. I could always modify a black pickup ring by removing the bottom edge and using the gk pickup instead of this edge i suppose! Thanks, Nick If you've got the external kit then I think the pickups are the same. It's just that the pickup is not soldered to the board. It's got a connector so you can plug it in. I think that's the only difference. Quote Link to comment Share on other sites More sharing options...
digi2t Posted June 24, 2008 Report Share Posted June 24, 2008 The external GK2A pickup is equipped with a plug to the board. I recently took one apart and installed it as an internal on my explorer. It's a job and a half to do, and I don't think I'll do it again. I had to unsolder the pup lead and transfer the wires to the underside of the pu for a cleaner look. I also had to extension the 13 pin plug. Not to mention routering the jack end of the guitar to incorporate the 2 jacks and the body for the board. See the pics below; Finished view Pup view Internal layout Internal closeup Jack plate Key ingredients (apart from the usual woodworking affair); A good soldering iron, solder vacuum, small curved hemostat clamp, and heatshrink. You may notice the connector that I installed between the board and the output jack. This was done to keep the installation somewhat modular. If the board screws up, I can just pop it out and put in a new one. Oh yeah, I almost forgot... lay off the caffine and candy bars for about a week before attempting this. The wires are tiny and the soldering tedious. About 5 to 6 hours of work including modifing the pickgaurd. I cut up the external casing and used it as a template for this. Cheers Quote Link to comment Share on other sites More sharing options...
Saber Posted June 24, 2008 Report Share Posted June 24, 2008 The thing I don't like about the typical installation of the GK pickup is that the long end protrudes above the lo-E string where it comes in contact with my picking hand. I reversed the six pickup wires so that I could place the protruding end out of the way below the Hi-E string. Quote Link to comment Share on other sites More sharing options...
dh7892 Posted June 25, 2008 Report Share Posted June 25, 2008 The thing I don't like about the typical installation of the GK pickup is that the long end protrudes above the lo-E string where it comes in contact with my picking hand. I reversed the six pickup wires so that I could place the protruding end out of the way below the Hi-E string. Why didn't you just install it the other way round? That's what I did with my external GK in my JEM and it works fine. You just have to configure your VG box so it knows you're that way round. Or perhaps that's only possible with the VG-99? Was this not possible with the VG-88 and VG-8? Quote Link to comment Share on other sites More sharing options...
Saber Posted June 25, 2008 Report Share Posted June 25, 2008 (edited) The thing I don't like about the typical installation of the GK pickup is that the long end protrudes above the lo-E string where it comes in contact with my picking hand. I reversed the six pickup wires so that I could place the protruding end out of the way below the Hi-E string. Why didn't you just install it the other way round? That's what I did with my external GK in my JEM and it works fine. You just have to configure your VG box so it knows you're that way round. Or perhaps that's only possible with the VG-99? Was this not possible with the VG-88 and VG-8? Not all Roland guitar synths have that option, the older ones in particular. Edited June 25, 2008 by Saber Quote Link to comment Share on other sites More sharing options...
digi2t Posted June 25, 2008 Report Share Posted June 25, 2008 The thing I don't like about the typical installation of the GK pickup is that the long end protrudes above the lo-E string where it comes in contact with my picking hand. I reversed the six pickup wires so that I could place the protruding end out of the way below the Hi-E string. Why didn't you just install it the other way round? That's what I did with my external GK in my JEM and it works fine. You just have to configure your VG box so it knows you're that way round. Or perhaps that's only possible with the VG-99? Was this not possible with the VG-88 and VG-8? Not all Roland guitar synths have that option, the older ones in particular. Precisely. I read in several places plus the manual that this was a no no for the GK2A pup. Besides, doesn`t bother me at all, so bonus. Cheers Quote Link to comment Share on other sites More sharing options...
dh7892 Posted June 26, 2008 Report Share Posted June 26, 2008 Not all Roland guitar synths have that option, the older ones in particular. OK, thought so. the 99 is my first VG unit so I guess I've never had to worry about it. I think I would find the unit very annoying if I had to use it "wire-up" because it looks to sit right where I want my picking hand. I suppose it's just a matter of picking style and you could probably learn to get used to it. Quote Link to comment Share on other sites More sharing options...
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