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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abhijitnath

Did anyone else have a go at this? Any luck at all with piezos triggering FTP with dynamic range intact?

utensil

#26
This post and was originally in a separate thread and thankfully Elantric correctly moved here:

I recently acquired a 7 string Godin Grand Concert Nylon String with Synth Access, I love playing it so much I wanted to use the Triple Play with it and since it won't work with magnetic pickups,  it resurrected my need to be able to plug in the FTP to the 13 pin port.

After a few experiments , heres an update on connecting various piezo system outputs directly into the FTP which may be useful to someone else trying it:

1) Graphtech Piezo's directly into the FTP are too weak a signal and doesn't register much in the FTP app

2) Graphtech 13 pin output is from their powered pre-amp is too strong requiring attenuation with trimpots.

3) The output from the Godin's 13 pin UNPOWERED RMC polydrive is in the right range and can be plugged directly into the triple play.THIS IS GREAT NEWS!! a direct 13 pin to FTP adapter can be made and is just a matter of connecting wires and requires no additional batteries , trimpots etc.

4) Output from the Godin's powered RMC polydrive is similar to the Graphtech and too strong requiring trimpots

So removing the original FTP magnetic pickup, the original connecter needs to be connected to the guitar output pins 1-6 and the shield. I chose to include the trimpots so I could use it with any 13 of my graphtech 13 pin guitars as well. This also requires a battery (+ve connected to pin 12 -ve to ground) to power the pre-amps of graphtech guitars. For the Godin guitar , The trimpots are not used and no battery attached.

The end result is very satisfactory, I'm using the 13 pin output of my Nylon string with the FTP and I don't feel there is any performance degradation from the way the FTP works mounted on my other guitar.

If anyone is interested in the comparison, I have a guitar with a mounted FTP and a 13 pin output from graphtech pickups which I could test both triple plays simultaneously but I would need some advice on how to set up the comparison (i.e which software to use to measure the differences in recorded midi).

Some Pics also included:



CodeSmart

Nice work  :)
What about Roland GK-3/Kit. Does magnetic pickups works without level mod?
But I got more gear than I need...and I like it!

utensil

I'm pretty confident it would work just as well as with the other powered options since their outputs are all probably in same spec range for receiving devices but that it would also require attenuation due to the signal being too hot. The GK mag (without it's pre-amp ) works as a replacement for the FTP mag but it is less sensitive so needs to be installed at ideal distance from strings.

The adapter detailed above won't work in its current form with the GK as the graphtech and polydrive require +7 V on pin 12 whereas the GK kit also needs -7v supplied on pin 13, this could be done with a second battery

I guess it could be useful if you have an internal GK installation so you don't have to mount a second pickup . it's also quick way to share the same FTP with multiple guitars

abhijitnath

#29
Bump.
Anyone with any luck getting Triple Play and 13 pin outs working from one pickup, either magnetic or piezo?

utensil

#30
Hey just saw this was bumped, yes I did finally get something useful together which allows to connect the FTP to either a magnetic or piezo based 13 pin output. (see posts above)









Elantric


utensil

I'm really interested to know of anyone elses differing experience of which of the 13 pin systems puts the signals in the sweet spot of ranges so no attenuation or amplification is required.

I was really pleasantly surprised to find that the RMC system on my Godin Grand Concert (2008 polydrive) guitar outputs individual string signals even with the battery REMOVED. My Graphtech guitars have absolutely no signal output when not powered.

In fact, this passive system is the exact perfect range for the FTP (and I'm assuming they've used RMC pickups and polydrive on the montreal triple play as well since I can't spot a mag hex pickup or additional battery slot for a pre-amp).

Anyone also have an idea of where one could get the connector that connects the FTP mag pickup to the circuit board. I used the existing one from the mag pickup but if I had known where to get them one could easily keep the FTP magnetic pickup intact making this completely reversible.


Elantric

#33
QuoteAnyone also have an idea of where one could get the connector that connects the FTP mag pickup to the circuit board. I used the existing one from the mag pickup but if I had known where to get them one could easily keep the FTP magnetic pickup intact making this completely reversible.

8-Pin header connector Sources
https://www.vguitarforums.com/smf/index.php?topic=9094.0


http://www.ebay.com/itm/Micro-JST-1-5-ZH-8-Pin-Connector-Plug-w-Wire-x-10-sets-/121139377810?pt=Radio_Control_Parts_Accessories&hash=item1c34783692

utensil

THANKS!!

missed this thread, Am planning on making an adapter without any battery or trimpots since I'm pretty much using this triple play only with my Godin. I'll keep the existing one in case I want to use on another guitar

abhijitnath

OOh- this is all great. For the DIY challenged (like me), anybody making this into a product that one can buy? That would be awesome!

utensil

Don't see it as all that practical, one would need to know the end piezo's and preamp that are being used. The one I've put together should work for any RMC, LR bags, Graphtech combinations but not for a Roland GK 13 pin since it requires the negative power supped. This could be achieved via another battery.

I guess one could make a common adapter with two 9 v batteries and 6 trim pots which would work for any 13 pin system but would still require the end user to open up his/her FTP to unplug the provided mag pickup and plug in the replacement adapter most likely voiding the warrantee. I think that kind of puts it into the space of DIY anyway and said potential buyer could just put together their own adapter.

I would think fish man could easily sell the FTP with a switchable pickup system, i.e either the magnetic or 13 pin adapter , but I think this would be a really small market.

abhijitnath

Thanks a ton! I will get in touch with you over PM for some help. Hope that's ok!

utensil

Sure no problem, happy to share any info

KastorVGF

#39
Hello utensil, I must say you did a very great job and I'm going to follow you! However, 2 black wires (the ground and the ground shield) in the 8 pin header which connected to the FTP directly make me confused. I draw a circuit diagram which I am planning to do with. Please tell me if there are any mistake(s). Thank you!!!!!




utensil

Quote from: KastorVGF on July 27, 2014, 09:04:26 PM
Hello utensil, I must say you did a very great job and I'm going to follow you! However, 2 black wires (the ground and the ground shield) in the 8 pin header which connected to the FTP directly make me confused. I draw a circuit diagram which I am planning to do with. Please tell me if there are any mistake(s). Thank you!!!!!

Hey KastorVGF

your drawing is pretty much exactly how I wired it. The pins on the 13 pin correspond correctly assuming you're looking into the cable (male) part not into the socket, but I'm assuming you've already looked it up since you're planning seems on track. If I remember , the the 2 black cables coming from the magnetic pickup are a common ground (can be confirm that they are connected if you have a multimeter handy). Either way your drawing is exactly how I've wired it. FYI I used 10k pots which seem to work fine.

What type of 13 pin system are you using it with? , I'm assuming  it's not intended for a Roland GK (internal or external) as your leaving out the 13 pin -7v as I did. It works fine with the Graphtech system and the RMC. also if you managed to get the 8 pin connector then I'd suggest keeping your original magnetic pickup intact as it would be trivial to restore your FTP back to original state should you ever want.

I'm interested you hear your results so please share. As I mentioned I've been using this on and off  as well as an unmodified FTP and I can't really notice any difference in performance.



KastorVGF

#41
Eventually, I have finished it this afternoon. It is not too difficult but you do need tools to do this (I do this in the Lab. of my university xD).
But I must say, as utensil, this adapter give a extremely good result!! I use this with the Graph Tech Ghost Hexpander system which is much better than the origin magnetic hex-pickup!!
Thank you for this post as searching from Google, here is the only place that teach people to make the adapter.
It is very easy to make it on your own, so check this out if you are not satisfied with the magnetic PU!!


utensil

Quote from: KastorVGF on August 04, 2014, 03:46:39 AM
Eventually, I have finished it this afternoon. It is not too difficult but you do need tools to do this (I do this in the Lab. of my university xD).
But I must say, as utensil, this adapter give a extremely good result!! I use this with the Graph Tech Ghost Hexpander system which is much better than the origin magnetic hex-pickup!!
Thank you for this post as searching from Google, here is the only place that teach people to make the adapter.
It is very easy to make it on your own, so check this out if you are not satisfied with the magnetic PU!!

I too find it works really well, and I've been using it with my nylon string which wasn't possible without the adapter. I would think it would have been nice if fishman did this for us but either way at least it works.


gumbo

...and if you feel like one day building it into some sort of a project box and using a good 13-pin jack...I can probably help you there!!   ;)

Cheers,
Peter
Read slower!!!   ....I'm typing as fast as I can...

utensil

#44
Quote from: gumbo on August 05, 2014, 03:30:13 AM
...and if you feel like one day building it into some sort of a project box and using a good 13-pin jack...I can probably help you there!!   ;)

Cheers,
Peter

i agree, these tools while new r expected to serve a long span of duty to our musical whims and so the more durable the better. Unfortunately being based in the U.A.E (as well as my shoddy but self sufficient looking diy work) makes me an unlikely supplier to this market, perhaps KastorVGF or some who can do as neat a job would be placed correctly. Im not sure what the demand for a 13 pin to FTP adapter is , but i sure would have been willing to pay a premium for an "pro"  gk version.


gumbo

Quote from: utensil on August 24, 2014, 03:24:51 PM
i agree, these tools while new r expected to serve a long span of duty to our musical whims and so the more durable the better. Unfortunately being based in the U.A.E (as well as my shoddy but self sufficient looking diy work) makes me an unlikely supplier to this market, perhaps KastorVGF or some who can do as neat a job would be placed correctly. Im not sure what the demand for a 13 pin to FTP adapter is , but i sure would have been willing to pay a premium for an "pro"  gk version.

Perhaps the three of us should talk more about the possibilities..
...PM me at any time..

Cheers,
Peter
Read slower!!!   ....I'm typing as fast as I can...

jassy

I would be very interested in some adapter to be able to use the FTP with my Godin guitars (several RMC and one Ghost) but also with my gk2 and gk3 guitars, so if someone would do some small box that can solve it I would want it.

Also a solution to connect one mag exaphonic PU simultaneously to a GK3 and the FTP would be very interesting.

My electronic skills are = 0 so I'm out of luck to be able to do it myself.

jassy

Quote from: Elantric on April 22, 2013, 04:47:20 PM
But I would prefer a method where I could feed the 13 pin gear along with the wireless MIDI from FTP.

                           |---->GK-3 -> 13pin
One hex PU 8 pin---|
                           |---->FTP controller > wireless MIDI

and the "Y" Adapter could be very straight forward.

Mount one hex PU of choice( FTP, GK-3, GK-2A, G1D, PU100, AIX-101) Let the stock Hex PU Cable be the input to the Custom Mag Hex PU "Y-Splitter" to feed two targets.

On this  Custom Mag Hex PU "Y-Splitter" there MUST be 12 "coupling capacitors": 
* Six Caps to feed the Hex PU String Inputs on FTP Controller.
* Six Caps to feed the Hex PU String Inputs on the GK3 preamp target.
The 12 Capacitors are required to prevent DC voltage interference and offsets between the two different systems.
Small Surface Mount caps are available, but must be of adequate capacity to pass the low fundamental frequencies of the Guitar.

http://en.wikipedia.org/wiki/Capacitive_coupling


Well after thinking about it I think The best solution for me would be able to use my guitars equipped with GK2 / 3 with the FTP Simultaneously.
So has anyone done this "Y-Splitter" with the 12 "coupling capacitors" already?
Could someone help explaining which type of connectors and capacitors would be needed to make that splitter to connect a GK2/3 and a FTP? (a link to a store would be amazing  :D)
Thank you.

CodeSmart

I 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?
But I got more gear than I need...and I like it!

Elantric

#49
Quote- A "FTP" connector to connect to FTP wart replacing hex pickup (Q1: what connector is that/footprint ?)

Fishman hex PU employs identical 8 pin connector and wiring pinout as a stock Roland GK-3 PU 

In other words - if you own a guitar that already has a GK-3 hex PU installed - you can easily swap the GK-3 "wart" for the FTP "wart".




Here's the inside of FTP -the hex PU connector is on the upper left  - next to the battery





Details on the 8 pin connector
https://www.vguitarforums.com/smf/index.php?topic=9094.0