FTP - DIY adapter to use GK 13 Pin Guitars with Tripleplay

Started by utensil, April 21, 2013, 01:29:52 PM

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musicman65

Quote from: CodeSmart on October 14, 2014, 03:51:30 PMI don't have a FTP myself but it sounds like you are looking for this (?):

A small strap box with the FTP wart attached to the outside (or is the wart still on the guitar?)
- A 13-pin input connector (for 13-pin guitar)
- A 13-pin output connector (for Roland GR/VG/GP)
- A "FTP" connector to connect to FTP wart replacing hex pickup (Q1: what connector is that/footprint ?)
- A compartment for two 9V batteries to power the 13-pin input connector +/- 7V pins (Q2: and power/charge FTP?. At what voltage would that be?)
- Automatically disconnect batteries when VG/GR is connected (using Power from synth instead)
- DC separation of audio circuits
- ONE knob controlling the volume of all six strings to FTP (ranging from damping to amplifying signal using a 6-channel voltage controlled audio chip)

Above is doable but what is the market?  
How many wants to temper with their expensive FTP wart?
I would love the better triggering/tracking of the FTP but have ZERO interest in having to equip my guitar with their pickup, having a PC in my rig, or going partially wireless...what's the point? I'm not giving up my GK hex wired VG99 rig, alt tuning, or any of the other awesome features of GK modeling capabilities.

A box that allows the FTP wart to sit on the gear end of my GK cable would be the only way I'd want to use an FTP. I can't figure out why a floor or rack model isn't offered already?

Elantric

#51
QuoteA box that allows the FTP wart to sit on the gear end of my GK cable would be the only way I'd want to use an FTP. I can't figure out why a floor or rack model isn't offered already?

All the info a clever DIY'er needs to create such an adapter for the FTP is already here in this thread - start at the 1st post!


musicman65

Quote from: Elantric on October 14, 2014, 10:03:36 PM
All the info a clever DIY'er needs to create such an adapter for the FTP is already here in this thread - start at the 1st post!
Thanks Elantric...backtracked and now up to speed. Not sure I have the time for another DIY project. Maybe after the new year. :) If anyone does make an "Adapter Box" I'd be interested.

MusicOverGear

I just put this circuit on perf inside my GP-10, so that my GK guitar is driving both the GP-10 and FTP. The FTP is permanently stuck to my pedalboard. It's working great right now - took about 2 hours, including a trip to the electronics store, where they damn near laughed me out of the building for looking for molex parts with 1.5mm pitch. Instead of waiting for a pre-assembled one to arrive from China - or even slower, using my wits to find one closer LOL - I just used the pads on the bottom of the board that must be meant as test points or something - they are labeled 1-7 for strings and ground.

I wanted to share a problem I ran into. I followed Kastor's schemo from p1 of this thread and the signal was still too hot for my FTP. So I just added an additional 10k resistor between the GK jack and the wiper of the pot and I was able to adjust each string down to range. To adjust I set sensitivity in FTP to 8 for each string and then got the pot as close to perfect as I could. I played for a few minutes and adjusted until the lights looked right and it felt and sounded balanced from string to string.

When I was inside my GP-10 - after I was halfway done and too lazy to turn back and rethink the project - it occurred to me that I could have mounted the FTP internally inside the GP-10 - left switched on and running off mains power - there is tons of empty space in there. IDK what would happen if I broke power off from the GP-10's input and used e.g. a 3v step-down converter - probably noise LOL. Anyway that would be a good project for someone with the chops. I'm going to use my hack job as it is until my shoddy work breaks down; by then I'll have some better ideas ready to go.

Anyway FYI for anyone doing this with a GK guitar - seems like the signal needs a little extra resistance to get it within range. 

whippinpost91850

A picture would be really cool  8)

MusicOverGear

#55
Sorry  poor pic  I'm at my gig and my battery is low.  FTP is in front of the birds logo

MusicOverGear

#56
Dam i don't think it uploaded

Try this
https://picasaweb.google.com/m/zoom?uname=107005125598970288451&aid=6044972183408016657&id=6085478755201521474&viewportWidth=320&viewportHeight=416

EDIT:
Okay next day now. I didn't have time to throw together a MainStage project and test it before leaving yesterday. But I can say that the mod does not interfere with the function of the GP-10. I've been using Logic for about an hour this AM and no problems so far - FTP works pretty much like it did mounted to a separate guitar.

I've already had two ideas for reworking this mod. One, to rework the whole setup with a proper layered pedalboard in a proper case (right now it's just a guitar shaped board that rides in a double gig bag). That way I could put all PSU's out of sight and just plug in mains power to the pedalboard - this is how I always did my tube amp pedalboards. The payoff for FTP is that that would give me a chance to put its fragile enclosure further out of the way AND figure out a way to just leave it switched on and give it its own PSU.

BTW I removed the snaggy type protrusions from the FTP - the lever for the switch and the knob for the pot.   

Elantric

Since you have relocated the FTP Controller onto the floor with external Gk13 pin input  - like utensil has done
13 Pin to FTP adapter
https://www.vguitarforums.com/smf/index.php?topic=8413.25

The FTP battery is 3.7VDC



Why not remove the FTP Li-Ion battery - and run it from a 3.7VDC supply?

Older Nokia Cell phone Power adapters should work fine
Power Supply Adapter NOKIA ACP-7U AC / DC 3.7v 350mA
http://www.ebay.com/itm/Power-Supply-Adapter-NOKIA-ACP-7U-AC-DC-3-7v-350mA-/261673825117?pt=Multipurpose_AC_to_DC_Adapters&hash=item3cecf9b35d


Vade

@ MOG

A quick question about your setup inside your GP-10. What did you use to split the 13 pin feed and send it to your FTP? Any pictures you'd care to post would be really helpful to those of us who had to Google terms like "perf" and "Molex" to try to get up to speed.
Drachen; Fender FTP Strat w/internal GK-3, Godin xtSA w/FTP, Boss GP-10, VoiceLive 3, Scarlett 18i8, ZBox IQ01, On-Lap 1502i, D:fine 4088, 4E Dual Axis Exp Pedal, VoiceSolo FX-150, Yamaha DXR 10, Gem. M2 Flute, Special 20 Harmonicas. Fender Deluxe Reverb Mahogany Cane.

https://soundcloud.com/vadie

MusicOverGear

#59
Elantric thanks for ideas. Yeah that seems best long-term. However now my setup is as ultralight as possible, and as a consequence my PSU's are just carried with my handful of cables - they aren't installed. If I switch to a proper pedalboard I will do that. Did utensil power his by transformer?

Vade sorry I didn't take pics while I was inside. Basically I just followed Kastor's schemo exactly. I soldered an extra 7 wires directly to the GK input jack. Those go a volume control just like in a guitar - the input goes to wiper, the output goes to lug #3 on the pot, and ground is lug #1. Just like in Kastor's schemo. The only thing I changed was adding an extra resistor. I did that because the cheap trimpots I used didn't have good enough resolution at the very bottom of their travel to get the level I wanted; it went from OFF to TOO LOUD.

I used one of the really nice jacks from Gumbo on this forum, but it would actually be easier to use one of Roland's stock jacks because you can just solder your wires to the solder side of the PCB.

HTH
Michael

PS Vade do NOT emulate my methodology on this - I did mine as a quick kludge to get it going. You really want to use the correct molex connector, plus it would be a lot smarter to use a proper connector on the chassis of the GP-10 (I just ran wires directly out from my PCB). I figured maybe I would use CAT5 if I eventually rework this mod on a proper pedalboard, but IDK if that's a good choice. I'm sure it's better than nothing, which is what I used on my mod LOL

Vade

#60
@ MOG

Thanks for the quick reply. That clears things up as I hadn't realized Kastor's schematic was about a direct connection to the 13 pin connector; probably skimming too much. So if I understand your suggestion not to kludge then it would involve a Molex (or Cat5 connector) on your homemade FTP perf -> a connector cable -> a Molex on or near the GP-10 perf which would serve to split the 13 pin input into a GP-10 leg and an FTP leg. I've never poked around inside my GP-10 so I'll look around for a pic and if I get to feeling bold I'll pull my GP-10 off my pedal board and take a look inside.

P.S. The more I think about it the more I'm inclined to just leave well enough alone. My FTP isn't really in my way mounted on my guitar. I've literally had a soldering iron on a PCB just once before when trying to eliminate a cold solder joint. I can't read schematics (yet) and I don't understand the function of the various components on the PCBs (yet). Do I really want to mess about with two rather expensive components (FTP & GP-10) integral to my rig and make that my first real foray into PCB and modding? All in the attempt to eliminate the modest inconvenience of a wart? I'm well aware that this isn't a particularly challenging project but I still think I'll cheer you lot on and take a bit more time to get the lay of the land before digging into a project like this. I've plenty of other challenges to meet before my rig is fully functional and I'd best keep digging away at those.
Drachen; Fender FTP Strat w/internal GK-3, Godin xtSA w/FTP, Boss GP-10, VoiceLive 3, Scarlett 18i8, ZBox IQ01, On-Lap 1502i, D:fine 4088, 4E Dual Axis Exp Pedal, VoiceSolo FX-150, Yamaha DXR 10, Gem. M2 Flute, Special 20 Harmonicas. Fender Deluxe Reverb Mahogany Cane.

https://soundcloud.com/vadie

Elantric

#61
QuotePS Vade do NOT emulate my methodology on this - I did mine as a quick kludge to get it going. You really want to use the correct molex connector, plus it would be a lot smarter to use a proper connector on the chassis of the GP-10 (I just ran wires directly out from my PCB). I figured maybe I would use CAT5 if I eventually rework this mod on a proper pedalboard, but IDK if that's a good choice. I'm sure it's better than nothing, which is what I used on my mod LOL

Find bulk of the DIY GK parts and molex connectors in this area
VGuitar Forums > Guitars and Pickups > GK-13 Reference Library
https://www.vguitarforums.com/smf/index.php?board=65.0

GK-3 Internal 8-Pin header connector sources
https://www.vguitarforums.com/smf/index.php?topic=9094.0


and scan the DIY Posts here for parts sources

DIY Hardware
https://www.vguitarforums.com/smf/index.php?board=21.0

http://www.doctronics.co.uk/prototyp.htm



http://www.makezine.com/

http://www.musicianstechcentral.com/midihard.html

http://www.audiomulch.com/midipic/

http://www.mini-itx.com/

http://www.midibox.org/users/tor_arne/midibox64_walkthrough/index.html

http://forums.benheck.com/

http://www.maxmidi.com/diy/

http://www.doctronics.co.uk/design.htm


Perf Board
http://www.amazon.com/Solderable-BreadBoard-matches-tie-point-breadboards/dp/B0040Z3012/ref=pd_rhf_ee_s_cp_2_T7DN?ie=UTF8&refRID=1KKSYB402V7X7RQCZ0TX


MusicOverGear

Man I am not qualified to be giving advice on electronics, but I will tell you what I can. Sounds like I'm at least one step ahead of you :)

I'm still a little fuzzy on what Utensil and Kastor are doing myself. I thought they were plugging their adapted FTP with 9V battery directly into the 13-pin jack of a guitar. But maybe not. Dunno - but that's where I got the idea for splitting off the GK jack in my GP-10, and it worked fine in mine.

Here's what I envision as a better version of my sloppy hack:

  • GK jack on GP-10 to perfboard circuit
  • perfboard is mounted with screws on standoffs (or other good mounting strategy - that's the only one I know)
  • perfboard circuit to CAT5 (or any good 7+conductor) chassis mounted jack that is mounted anywhere it makes sense. On mine it would be on the front panel between the PSU input and the edge
  • attach a CAT5 plug a cable assembly that has the correct molex connector ( Elantric posted a link to one like this: http://www.ebay.com/itm/111380528002 )
  • FTP run from a wall wart instead of battery and tucked into the ugly underbelly of a proper pedalboard, where it will be protected and out of sight

Based on my experience so far, that seems like it would be relatively solid. But like I said, I have no credentials in electronics. Also my mod has less than 10 hours of service under its belt, so it is far from proven.

Elantric

#63
ITs "What you see is what you get"

This is the FTP Controller  - modified by Utensil  - with hex PU removed and replaced by a DIN 13 pin connector ( Id make it a female myself) > 6 channel passive attenuator board (the white blob)  > to small molox header feeding the FTP controller using the former hex PU connector.



Like this:



This allows Any 13 pin guitar to use the FTP as a Guitar to MIDI converter. Still need to plug the FTP USB receiver into a PC/Mac/iPad+CCK or Raspberry Pi to drive a Synth 

Vade

Thanks for taking time to expand on your experiment MOG. As of now, I think that if the wart gets bothersome I'll go the modified guitar route. Especially since my current rig involves hauling just one guitar to a gig. Having the FTP and GK controls at hand at least permits of the possibility to make them practical. Perhaps modifying the FTP pad output to something more useful than simple patch up/down. Then there's the synth/sample volume issue. I'm still trying to find a good way to fade in/out the volume of synths etc. (which I'm thinking is going to be key to making them more than a background drone effect) and that FTP volume control might have a role to play in that scenario; although I've not gotten it working outside of the FTP software yet. I'll be interested in what you come up with as you've always something to teach when you post. Thanks again.
Drachen; Fender FTP Strat w/internal GK-3, Godin xtSA w/FTP, Boss GP-10, VoiceLive 3, Scarlett 18i8, ZBox IQ01, On-Lap 1502i, D:fine 4088, 4E Dual Axis Exp Pedal, VoiceSolo FX-150, Yamaha DXR 10, Gem. M2 Flute, Special 20 Harmonicas. Fender Deluxe Reverb Mahogany Cane.

https://soundcloud.com/vadie

BackDAWman

So....to get this straight. If I did the following on my GK3 to split the GK's Hex PU between the FTP and the 13pin wart I could have a virtual GR-55 if I plugged into my GP-10 with the 13pin connector and used my Kenton Host to plug in the FTP receiver and drive a SD-50. Only with the incredible tracking of the FTP and the awesome modeling of the GP-10.

                                     +
GK3 Hex PU Header 0----||------->Hex PU header of FTP
                                     +
GK3 Hex PU Header 0----||------->Hex PU header of FTP
                                     +
GK3 Hex PU Header 0----||------->Hex PU header of FTP
                                     +
GK3 Hex PU Header 0----||------->Hex PU header of FTP
                                     +
GK3 Hex PU Header 0----||------->Hex PU header of FTP
                                     +
GK3 Hex PU Header 0----||------->Hex PU header of FTP

GK3 Ground-------------------------> FTP ground

Elantric

for feeding two separate systems  - The series capacitors will block  / isolate DC voltage - but the FTP preamp  is more sensitive than the GK-3 preamp and as both MusicOverGear and Utensil have stated - you need to add a passive attenuator potentiometer for each string  - to run the output form each capacitor to one end of a 10k pot, - tie the other end to Analog Ground  - then use the the Pot middle lug ( the wiper)  to feed the input header on the Gk-3 using the same pinout as the Roland Gk-3 PU Input Header.

(GK-3 Schematics)
https://www.vguitarforums.com/smf/index.php?topic=73.0
Get the proper size 8 pin Molex connector parts on Ebay - the type mentioned here:
GK-3 Internal 8-Pin header connector sources

https://www.vguitarforums.com/smf/index.php?topic=9094.0
 

BackDAWman

So the FTP hex pu has less output than the GK? Then using the FTP pu as the main pu may be a better idea and increase sensitivity on the GK pre-amp. I only suggest this way as i don't have a schematic of the FTP internals. If the outputs were measurable then you could adjust the gain of the GK pre-amps to suit.

Just thinking out loud.

Has anyone got any specs of the two pu's?

Elantric

#68
Both Gk-3 Hex PU and FTP hex pickup are very close in output signal levels. The FTP has a bit higher output level.
In fact I have mentioned in a few existing FTP threads that if you already have a Guitar with perfectly mounted GK-3 PU - its rather straight forward to retain your existing GK-3 hex PU, and substitute  FTP Controller for the Gk-3 preamp

Remember Utensil's FTP Adapter interface is receiving signals not from the raw GK-3 PU - but rather from the GK-3's 13pin output  - after the GK-3's internal  opamp gain stage output  - thus the need for a custom 6 channel passive attenuator board with trim pots since he is feeding yet another opamp gain stage inside the FTP controller

QuoteSo the FTP hex pu has less output than the GK? Then using the FTP pu as the main pu may be a better idea and increase sensitivity on the GK pre-amp.


Remember more gain from the hex PU is not a good thing as this has consequences - like higher susceptibility to adjacent string crosstalk - and that ruins DSP generated Alt Tunings



BackDAWman

Yep. That's why I'd like to try my GK pu driving both the FTP wart and the GK-3 wart. One hex mag pu driving both sets of pre-amps. Wireless MIDI and modelling via the GP-10.

I can feel a project coming on....

Now all I need is time  ::)

Elantric

For those of us with multiple 13 pin guitars - its more attractive to place the FTP Controller down on the floor, and use a US-20 A/B/Y 13 selector for control

- The "FTP Controller" with its clobbered D-pad remains a flawed half baked mine field of trouble when mounted on the guitar for synth control at live gigs 

CodeSmart

My next switcher project (sometime 2015) will have a input 3Xhex selector chip with programmable gain. The output hex signal volume chip(s)  has per string (and per guitar input) programmable attenuation. This will accommodate both amplification and attenuation if needed. Who knows...might be useful for various FTP projects.
But I got more gear than I need...and I like it!

gumbo

Quote from: CodeSmart on November 26, 2014, 04:06:20 PM
My next switcher project (sometime 2015) will have a input 3Xhex selector chip with programmable gain. The output hex signal volume chip(s)  has per string (and per guitar input) programmable attenuation. This will accommodate both amplification and attenuation if needed. Who knows...might be useful for various FTP projects.


...so...  Mrs CodeSmart doesn't read these posts then...     ;D
Read slower!!!   ....I'm typing as fast as I can...

scratch17

I bought a 2015 SG Standard today. It arrives Monday or Tuesday at GC.

I have an FTP and a new GK-3. Obviously, I don't want to modify my SG, so splitting the GK-3 output to feed the FTP seems to be the way for me to go. I'm going to get a tech buddy to help me make this mod.

I'll let you know how it goes. My buddy is a really busy guy, so it will be a while.
Hamer Duotone, Brian Moore i213, Taylor 710 BCE 

VG-99, FC-300, RMC Fanout
RJM Mastermind GT10
Kemper Profiling Amp
Radial JDV Mk3, X-Amp
Mesa Recto Pre + 20/20
68 Fender Bandmaster (AB763)
Marshal AS80R

UA Apollo X6, Twin X, Logic Pro, Luna, Melodyne Studio

Rorster

Is it correct to assume that the FTP Controller  - modified by Utensil when used with a Godin LGX-SA or LGXT would permit the program up/down switch on the Godin, as well as the guitar/synth/combined guitar-synth switch to work? Also since these guitars have an onboard acoustic preamp for the piezos acoustic function, would that 9 volt battery preamp affect the FTP playability if/when combined with the acoustic function of the guitar. The Godin that Utensil uses has a 9 volt powered preamp I'm almost certain but I don't believe that this question has been specifically addressed.