Graph-Tech Ghost Info

Started by Elantric, March 10, 2008, 11:15:34 AM

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Beynon5

#150
Ah brilliant thanks for that! I have the original ribbon cable  so just hoping to copy it but soldering it and the board and using some decent cable :)

Thanks again

Feromon

Quote from:  Elantric on December 23, 2014, 01:43:03 AM


My biggest gripe with the GraphTech Hexpander is its high noise floor and poor dynamic range (compared to RMC) , forces the use of the COSM "N.S. (Noise Suppressor) full-time,



Hey Elantric! What do you mean by poor dynamic range?

I think Graphtech is much more natural in dynamic range than Rmc. Moreover, the sound of the Graphtech system is not harsh like the RMC in my opinion. But indeed, I agree that graphtech is very noisy when mixed together with magnetic pickups system. For example; NS1 carvin -nylon acoustic (ghost) is very silent and works flawlessly with gp10 (also gr300), but the same ghost system with Carvin SH65 with additional regular magnetic pickups is very noisy. Some bad grounded kind of noise.

Any advice to improve the sound by avoiding this noise. Maybe any modification in hardware?

Thank you for any response!

Elantric

#152
Its all about the design  - the RMC piezos are designed to have a tighter focused Piezo response contact area directly under the string  - by contrast the Ghost saddles will pickup vibration from all surface areas of the bridge saddle - including picking up substantial mechanical crosstalk from adjacent strings which directly messes up DSP Alt tunings ( More warbles) and creates poor Guitar to MIDI Tracking ( more false triggered ghost notes)  -

So to avoid crosstalk on ghost Piezo PUs, its necessary to lower the VG-99 / GR-55 / GP-10 GK String Sensitivity - and that lowers your available dynamic range 

The source for the Ghost hex PU High Noise floor ( when using COSM Modeling) is due to the Ghost MIDI Expander hex Piezo preamp board  - has more noise than RMC Polydrive Hex Piezo Preamp   

Feromon

Thank you Elantric for quick response!

Now I understand what you mean by dynamic range.
But like I said, the NS1 has not any problem with "noise floor". I use about 65-70sens setup for all strings without any glitches etc. exactly like in the the case with my godin with RMC.
Problem appears only in Carvin SH65 with its magnetic PUs/Graphtec mixed together system. And .. I don't need use the NoiseGate but I must permanently touch the strings ;)

Elantric

When you talk to most "Piezo Hex PU designers - they tend to assume the only use is Guitar to MIDI - so noise floor in the audio performance of the preamp for the 13 pin out electronics is often viewed as:

" whats the problem with a little noise - it will be masked during the Guitar to MIDI conversion anyway"      


Then COSM Modeling systems like the VG-8 came along and destroyed that concept  - the Strings , and GK preamp remain all  part of the signal path on COSM VGuitar systems (VG-8 to GP-10 )

Spatzi

#155
Just installed graphtech hexpander Kit into my Parker. Everything works except acoustic piano sounds/clav. I only hear two strings, bottom  E and A. All strings are set to full volume in the piano patch and all strings are equal volume in the Gl settings. Any ideas what is wrong?

Elantric


Alec Lee

I replaced the OEM Fishman piezos in my Parker with a Graphtech system.  It has more mechanical noise than my GK but I still get good results with it.

GuitarBuilder

I only have experience with the RMC piezo pickups in my Brian Moore iGuitar; they are quite good and don't seem to exhibit any issues.
"There's no-one left alive, it must be a draw"  Peter Gabriel 1973

mr shankly

Does anyone know the name of the connector that pushes onto the pins on the hexpander board?
Previously I've done 3 Hannes piezo bridges and they come with thes small connectors attached to the piezo wires that push straight onto the Graphtech board, but this time I'm using a piezo bridge that just gives you bare wires and I'm at a loss what to do. I'm in the UK but am willing to order from anywhere

HAMERMAN409

Not sure what brand connector system it is that they use but the connectors have a 2.0MM pitch.

I made my own connections using JST "PHD" series connectors. The only place you run into problems is when you have to use a pair of connectors next to each other since the JST connector housings have some extra material on the ends so you have to do some sanding if you want to butt two together,

Excluding ribbon connectors all of these systems use crimp pins inserted into plastic housings. The pins and housings are usually reasonably priced but the crimpers are usually very expensive. In my case I was lucky enough to have a crimper meant for a different pin that happened to work with the JST pins. At some point I did see a couple of reasonably priced crimpers on Amazon that I think may work but I have not tried them.

http://www.digikey.com/product-search/en/connectors-interconnects/rectangular-connectors-housings/1442556?k=PHD%20connector

http://www.amazon.com/dp/B002AVVO7K/ref=wl_it_dp_o_pC_S_ttl?_encoding=UTF8&colid=32CTXD0OWTGJ6&coliid=I2JBABLUWNO6LY

http://www.amazon.com/Crimping-Tool-Crimper-KF2510-Connector/dp/B00R1IPRM0/ref=sr_1_1?ie=UTF8&qid=1452017291&sr=8-1&keywords=pin+crimper+JST

Elantric

#161

gumbo

Get this crimper if you can...

http://www.amazon.com/Engineer-PA-09-Micro-Connector-Crimpers/dp/B002AVVO7K/ref=pd_bxgy_60_2?ie=UTF8&refRID=12MMHZYJTPTZ3QZXKGNE

..best price I've seen on it, and it WORKS!

BTW, I stock JST female connectors in 1.5 pitch, 8 way,  and 2.0 pitch 7,8, & 14 way , and female crimp pins to suit ..
PM me if you get stuck.

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

mr shankly

Thanks for all your help
Graphtech contacted me to let me know it is a Hirose product

http://www.digikey.co.uk/product-detail/en/A3B-12D-2C/H2005-ND/141198

Adonf

Hello my question, can we connect a Graph Tech Ghost kit using twelve o'clock taking the GR 55 to avoid an extra battery.

Thank you
Egsolidbody French Kit SM-DC Deluxe
Roland Gr 55
Line 6 Ux1
Soundcraft EPM8
katana MK2 100
Marshall Valvelstate 80v
Prs se Santana 2002
Focales Alpha 50

Elantric

#165
QuoteHello my question, can we connect a Graph Tech Ghost kit using twelve o'clock taking the GR 55 to avoid an extra battery.

Thank you

I assume you mean:

Can the GR-55's GK connector,  (with its +7VDC on pin #12, and -7VDC on pin#13 of the DIN13 jack ) be used to power the Graphtech Ghost MIDi Hexpander?

Yes



Adonf

thank you for the answer (with + 7VDC on pin No. 12, and -7VDC on pin # 13 of the DIN plug 13) so that was my question. ;)
Egsolidbody French Kit SM-DC Deluxe
Roland Gr 55
Line 6 Ux1
Soundcraft EPM8
katana MK2 100
Marshall Valvelstate 80v
Prs se Santana 2002
Focales Alpha 50

mapletop

hi i installed graph tect.everything works but 3 strings are louder then the other 3.i have changed the wire order in the summing board and it changes which strings are louder order.is it the main board?

admin

Quote from: mapletop on August 27, 2019, 04:21:38 PM
hi i installed graph tect.everything works but 3 strings are louder then the other 3.i have changed the wire order in the summing board and it changes which strings are louder order.is it the main board?

Prior to shipment these six piezo saddles were supposed to be matched as a set for equal sensitivity

Probably three Graph-Tech saddles were built in April 2016, and the other three were built in Sept 2017


MadMac

hello,
time to show some work :-)
well have a Parker Fly 95' and modernized the wiring and put in the Hexpander + piezo for Parker
replaced all toggles with new c&k and used now cts pot's + humbucker splitting...
for all interested attached is my working wiring for the Parker Fly...
added also a kill switch with led light...
no new holes nor any damage was done... only one hole for the piezo cables got little bigger...
the midi plug will be on the metal plate for battery... waiting for parts...
but will use a 14 pin connector which is much more secure and reliable ...
all is working and has very low noise... very very happy with the MOD...
much better as the original pizo's and no battery anymore...
no nasty GK-3 on my beauty ... same look as before... only a new toggle instead a pot...
2021 can come ...
thx
M.
life is what you make it...

MadMac

hello,
well just a follow up post...
have it working now a week with all plugs and switches...
also put in a Juggernout PU...
it's now a Fly 2021 ...
love the new Midi Plug very much...
that's professional... not that Roland Plastic plug hehe

Parker Fly Deluxe 2021
Hipshot tunes
C&K toggles & Emerson poti's / push/pull split Tone for single coil
Bare Knuckel Juggernout (bridge)
Hexpander Midi with new professional connector 14pin...
Killswitch with dimmable LED
absolute low noise wiring
no new hole no damage was made
get another Fly Standart 98' now... do the same Mod again...
Use SY-1000 now... sold my AxeFX II & my Fender & Gibson...
Parker Fly is all i'll need ... best Git to me...
M.
life is what you make it...

peter_dawson

That looks delicious. Love the illuminated socket :)

admin

https://www.vguitarforums.com/smf/index.php?topic=11861.msg246742#msg246742
If you read my reviews, I have been complaining every which way about how bad the GP-10 OSC synth tracks. You would too if you were at my house listening. Heartbreaking. The Osc synth sounds gorgeous.

I had all but given up on it, shrugging and thinking my GraphTech Carvin SH-575 just couldn't get the @#$%#$ thing to track right.
But I sat on my floor and squinted at it with the disturbing look that only old men who have had to solve these kinds of problems for decades develop. Not pretty.
I remembered that when I got my VG-99 the GraphTech pickups were way, way, way too hot for the VG to deal with.
BUT- I HAD ALREADY ACCOUNTED FOR THAT, HADN'T I? My low E was set at 25, for God's sake. Isn't that low enough? Really?

No.

I took my low E down to 10. I adjusted the other strings accordingly with the highest being 14. That's low, my friends.

And the Osc synth now tracks much better. I have Velocity Cut on 1 or 2, and it behaves itself well enough to use it. Not bad. It's now a guitar synth, meaning you have to mute when needed and play cleanly and all that. But it is no longer a spastic monkey synthesizer.

The other voices play as well. This may not be my final settings, they may need to go up some.
But hear ye this: If you run a GraphTech guitar into this box, it is WAY WAY WAY TOO HOT for what Roland is expecting to see.

Turn it down.

nos4r2

#173
Heya
Been a while.
Just bought a wavestate - looking to get some ambient stuff going, and thought that maybe i might be able to use the VG99 /GR55 as a guitar to midi controller - so i dug the VG & Fc-300 out of the cupboard ( havent used it for a few years now) and have started to read their manuals again to get things setup.  Alas i remember why I put the VG99 away now.
I have a Holdsworth Carvin with the Graphtech built in. Love this guitar. The neck is so comfortable....can't go back to strat or Godin anymore...but after a factory reset, the sensitivity started up at 65 on each string, and damn it sounded bad.
Reread some of the stuff on here about RMC recommendation of setting everything to zero, and am slowly raising from there (eg B string). Any tips on the Bass and Treble settings ? ( +- 10)
It seems heaps of people have given up on trying to use piezo+13 pin for tracking of PCM sound on the GR55, and also having to dramatically re-EQ patches for the COSM sounds on VG, in order to get good sounds.
Any of the shared user patches setup for Graphtech ? Would be good to see what people have done to improve on the factory patches - Save me having to start from scratch, as well as give me some idea of what i'd need to try.
As i said, I'm looking to use the Carvin as a midi trigger for the Wavestate, so i gather thats not going to work out too well.
Anyone use a Graphtech piezo guitar as a midi controller ? Which worked better - the VG99 or the GR55 ? Midi or USB outs?
I've read about using a RMC OPT-01 subsonic filter module for the Gr-55 to improve tracking - but being in Australia we don't really have any here. Once you add up the dollar conversion and the extreme postage costs, this solution becomes expensive, esp if it still doesn't work out to make things great.
Pity about Wayne Jones no longer making those inline units - they looked perfect. Anyone have one for sale ?
Has anyone used the Primova subsonic filter on a Graphtech?
OR
Do I get a GK-3 bolt on for the times i want to use it as a controller? (still have a gk2/gk2a in the cupboard, as well as a VG8ex). I don't see the point of pulling out the Graphtech and replacing it with the GK kit. As a piezo sound goes, its not too bad, and I can use it (and mags) into the guitar input of  VG99 for parallel fx processing...

I'd forgotten how much drama comes with these Roland processors - hence why i haven't been on here, or bought any of their latest stuff.

aliensporebomb

The VG-99 is one of the best ambient machines ever made all by itself.  If you're using it as a guitar-to-midi box you definitely want to use a GK SENS level of 22 or less for any of the hex pickup solutions if you want to do guitar-to-midi or you will suffer with mistracking.

Many demos of what the VG-99 can do all by itself I've done here:  https://soundcloud.com/aliensporebomb
I've uploaded a fair amount of ambient patches for the unit at this site.

Good luck.


My music projects online at http://www.aliensporebomb.com/

GK Devices:  Roland VG-99, Boss GP-10, Boss SY-1000.