guitar synth system from hell, in progress..... the guitorchestron

Started by pinkjimiphoton, November 01, 2022, 09:53:11 AM

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still growing... added in a gr30 for dig poly synth, alternate midi chain, and its harmonizer feature.

the gr700 has been a couple year labor of love that involved a lot of diy repair stuff, mostly learned from you guys over the years, for which i'm grateful.

the 80017a vca/vcf chips all needed repair, which involve a bit of de/resoldering... i used SIP sockets for them installed on the board for ease of access if i need to replace one, and have two spares.... and a glass jar with some acetone, a razor blade and a dental pick, and an ass load of patience to get the epoxy they'd coated the chips with off... over the years, it absorbs water from the atmosphere to the point it becomes conductive and the synth just plain won't track... so ya gotta get it all off. and its all smd parts, the resistors and small caps are actually printed onto the substrate ceramic of each chip, and if ya fudge one, you need to be able to microsolder a replacement on... good luck. and ya gotta get all the crud out from under the legs of the smd chips.. fun fun fun! but it WORKS, and i managed to restore a formerly dead synth. i sent the earlier video to steve hunter, he was surprised it tracked so well.

also modded it to be able to have 4 banks of memory on a 64k card, it thinks each bank is a 16k card. ;)

all the mods for that sh** are on

rundown is kinda like...

the gr707 guitar is the source, which splits to 24 pin analog, and 13 pin modern digital environments. the 13 pin environment will eventually control a gr-d hex distortion and a roland vg 88 digital guitar environment.
the gr30 was chosen cuz it has a great sounding semi intelligent harmonizer which is a blast, and i can assign the harmony voices to any of the other synths or slaves i have if i want to, including the analogs with a bit of rewiring.
then the gr700 is the main synth.
the midi out of the 700 then goes  to the midi in of the behringer model d, a recreation of the moog model d as a desktop synth, i had rack ears made for it.
this gets top note priority always... if i play a chord, the top note of the chord is automatically played by this synth.
the midi thru then jumps down to the paia phatman, set for low note priority,  so its set for a phat analogish bass tone generally and its midi thru then goes to the behringer k2, set for last note priority. the k2 is a sequential circuits prophet clone.
i can also take a midi out signal completely independently from the gr30, which will go to a merge box with the midi signal from the gr300, and will then go to an 8 out programmable midi thru box, so i will be able to address any of the midi stuff i connect to it and control the midi stuff completely independent of the audio... this is where the real time arranger comes in, which will generate drums and bass in real time based on what i play.
all this in stereo, with stereo effects.
so there's the:
1: straight guitar into marshall
2: analog poly synth environment
3: analog mono synth environment, x 3
4: digital poly synth environment
5: digital guitar environment
6: hex fuzz environment
all under individual control, in real time...
and then the rack i still have to integrate has 3 midi slave units, axon ax100 and yamaha 13 pin controller interfaces which both include 1/4" jacks so anything you plug into them can become a mono midi controller, including your voice,
and converters for 24 pin to midi and 13 pin to midi, and the controller brain for the ibanez img system, as well... even has a marshall rack preamp to loop into it if you want a mixed in guitar signal with any of the digital synths.
it is literally ****ing insane.

i forgot to mention there's a 24 pin thru box/a/b/y 13 pin box in there, as well, that allows me to drive the antique 24 pin analog and the modern 13 pin digital guitar synths and stuff simultaneously, that was made by a chap in france. pricey, but was worth it.

i can pretty much make almost any sound i want or can imagine with this monstrosity. i'm calling it the guitorchestron.

still very much a work in progress. lotta more diy stuff to come, gotta make a few mods to the paia fatman, finish the restoration of the gr700... needs all its tactile switches replaced... gotta fab some new pins for two broken footswitch pads, and eventually recap the rest of it.... always something with all old gear ;)

but man, this thing is cool, and all the diy stuff i learned is the only reason i could make this happen.


Oh great, another retired  old hippie like me tripping out on guitar synths. 8)  :)  ;D  8)


But when the alien invasion comes, he finds the only sound setting that can pacify them....and saves the world.


If negotians break down (with Martians at least) Slim Whitman's Indian Love Song has been scientifically tested and shown to be effective as a weapon. There was a full length documentary some years back demonstrating it.