a couple notes on ressurecting roland 80017a vca/vcf ic's <junos, gr700 etc>

[pinkjimiphoton]

the best place for resources is wayne joness's excellent site,
https://www.joness.com/gr300/GR-700.htm

that dude is both a gentleman AND a scholar.
anyways, i was recently gifted a semi-working gr700 guitar synth with the 24 pin cable, a gr202 guitar synth controller, and a gr300 that just needed an led replaced.

the 700 worked perfectly at first, til i hit a patch with a random sample and hold. at first, i thought the hold pedal function had stuck, but cleaning it had no effect.

so did some research, which led to the 80017a chips being faulty, and that they could well be repairable.
what it is is a couple of dip chips with printed resistors and smd caps on a ceramic substrate thats sealed in a rubbery plastic kinda stuff that in some cases is still gooey inside 40 years later, kinda like the insulation that turned to sticky goo in old japanese guitars or the black foam insulation that would rot into hideous foul goo...


anyways, over time, the stuff becomes more and more conductive til it causes all kinds of weirdness.
supposedly, if you can get it off, the chips will be "restored".

and it does, in fact, work that way.

anyways, the prevailing wisdom is to scrape off some of some of the goop on the top and sides of the chip.
the theory is this will let solvent in to help dissolve the goop. ya soak 'em for a day or so, then start chipping away at it.

to dissolve the goop, use acetone. pour about 4 fingers into a glass jar with a tight fitting lid and set aside for a minute.

anyways, me never being afraid to let the magick smoke outta stuff, decided to see if there may be a better way, for me, i found one. i don't advise you do this, caveats apply, acetone is nasty shit, as is the goop on these... if ya mess it up, mess yourself up, poltergeists start flying out of your television set or whatever, i'm not responsible.
wear gloves and protective glasses if ya do it my way, as shit will be flying off and shrapnel in the eyes sucks.

i took bog standard single edge razor blades and hacked away at the epoxy goop til i could see the white card beneath. i did this on the top of the card, the sides of the card, and as much of the bottom as i could get at. i didn't @#$% with where the pins were coming out.

i used a small file to grind off the rest i couldn't get with the razor blades. i found a single edge was good for about one card. the junos and gr700 use 6 cards a piece. they DID break, and pieces DID go flying in my face, and bounce off my glasses. but i was determined, insane, possibly a bit of both.

once i had clear margins around the chips, with the bumps facing me, i used the razor wherever possible to start lifting the epoxy to chip at least some off.

look on wayne's page at the stripped chips to see where NOT to do this. i didn't, and had to buy two replacements <tho my bassist, jolly roger fixed 'em at work for me>... one where i had sliced one of the smd caps in half ... it still worked...

and the smd caps are 680p @50v by the way, cuz they're not marked on the schematic roland made available...

and another where later, as i was cleaning goo between ic leads, i inadvertantly lifted a leg and f'd up a pad... he fixed that one, too. its what he does.

one more i had actually sliced one of the caps off completely. it still worked, but had a bit of fuzz to the filter on that one string. thats been fixed now too.

so i gotta couple spares... may be handy. also updated it to the newest firmware, or ordered it anyways and will be installing it when it comes in.. but i digress...

so anyways, socket where the chips on the board went, too. makes life a lot easier. you need 12 hole sip socket strips, and use your iron on hole #11 to push the pin/socket out. that way you have a proper key and it will fit the circuit board.
i found to desolder, use a strong sucker. a little fresh solder on the tip of the iron, heat the joint, suck the solder out, and use some needlenose to wiggle the pin around and it should come free fairly easily. do this 11 more times per chip.

took me 4 hours and myriad bingers to accomplish. but i'm slow.

anyways, so ya got your chips out, ya got the edges scraped clear, ya chipped off some of the crud on the bump side of the chip... the non-bump side is safer, but ya really wanna get some solvent in there..

next, soak that shit. throw 'em all in your jar of acetone  together, and seal the lid of the jar.
let 'em soak over nite. the reccomended time is 12-48 hours. i was figuring on 72 hours if needed.

when i checked them the next day, you could see where it was coming loose and beginning to bubble off.

me, being the impatient sort, hearkened back to my days of making parts for WMD's for the goobermint and thought, "man, i wish i had a tumbler"....

a tumbler is like a washing machine full of ceramic stones, and water with a bit of solvent in it. ya throw parts in, and it deburrs them, and polishes them to a nice uniform satin finish in industrial situations.

so i decided to just use the chips for the stones, and began aggravating the jar...errr... agitating the jar.

kindq like you'd swirl your fav beverage "on the rocks" while mindlessly doing other stuff, watching the other idiot box, blatherskiting with friends on the phone or whatever.

anyways, by about 24 hours, due to the aggravation of the agitation, the epoxy crud was really beginning to come off the backsides of all the chips, so i did a test one and found i could literally just pull the crud off with my fingers in one piece.

then i used a dental tool, some tiny files i bummed off my dentist that she uses for doing root canals, and started making sure i got as much of the goop out from between the pins of the ic's as possible. you may need to re-dunk the chips to get it all to loosen up, as the acetone evaporates, it starts to get hard again.

small sharp screwdrivers and single edge razorblades pretty much ruled. if ya use the razor, you can, if careful, juuuuuuuustslice between the legs of the 2 chips, and then drag out the goop between the legs and under them. lotta work... but in the end, good.

also make sure ya get off all the goop between the legs that plug/solder into the pcb inside the synth. once you do, install the chips into the sockets you installed, and be rewarded with a once again functioning juno or gr700 synth. you will have to recalibrate, but that info is on wayne's site, too in the service manual.

dissasembly isn't as bad as it sounds... couple nylon multiconnectors and screws, and the whole board comes right out. well designed and easy to work on.

anyways, thats my experience with doing this. it worked, it was positive, and for what it is, the 700 is kinda cool

if ya wanna play berlin's "take my breath away" in particular. it just SOUNDS LIKE the 1980's.

the gr300, being a poly analog, is much much cooler.

there's a reccomended mod to make the guitar's hex fuzz stronger, where you change two resistors from stock values of 56k and 2.2k to 100k and 5.1k.

but i don't like it... you do bump up the output of the synth by 12db, but the filter gets harsher and gnarlier sounding and loses the sweetness and ability to really dial in as many sounds in my opinion from the guitar.
i have owned a lot of analogs over the years <2600, mini and micro moog,prophet 5, juno 6, 60, 106, eml 101 etc etc> and this mod, to me, as a synthesist, is a great mod for a guitarist, but too much for my taste.

i would recommend instead splitting wayne's values to 68k and 3.3/3.6/3.9k instead. that will give about half the boost, and may make the filter response a bit sweeter while still driving it harder and about doubling the output.

but anyways... i hope some poor bastidge who gets one of these someday finds some of this info useful.

rock on, always

[Ry]

Thank you for this!  I have a much loved Juno 106 that I found in a pawn shop in the mid-90s.  I also have a Juno 60 that I picked up a couple years later.  They both worked the last time I fired them up, but I've been meaning to chip away the goop on the 106 (I don't know that the 60 has the same stuff) before playing it again.  This helps a lot in my research of what needs to be done.

I should probably change out the memory backup batteries and filter caps again while I'm in there...

[DIY Bass]

I just have to say that you are completely insane doing that - and I mean that in a good way.  It seems to me that you are never afraid to try something a little crazy to see if you can make it work - and usually it seems that you can.  Well done.

[Mark Hammer]

I have a dysfunctional Juno-106 sitting in the basement, that I also picked up cheap.  I've never been able to determine whether the 6 gooped modules all work right, because the thing doesn't boot.  There might be an analog tone-generation issue, but for now the digital side is holding up the show.

[pinkjimiphoton]

I have a dysfunctional Juno-106 sitting in the basement, that I also picked up cheap.  I've never been able to determine whether the 6 gooped modules all work right, because the thing doesn't boot.  There might be an analog tone-generation issue, but for now the digital side is holding up the show.

in my limited experience working on junos many years ago for my old keyboardist mike zappulla, i found that rebuilding the power supply brought his back from the shades when it wouldn't boot.

9 times out of ten, its just a filter cap that shorts or goes open, then the whole thing just is dead.

mark, bro, with some of the amazing shit you've done, you can most definitely handle the task!!

the worst part is the desoldering.

i take no credit for the repair, the idea behind it, or anything... i just figured out agitation would speed the process.

and going around as much of the circumference makes it way way faster for impatient guys like


oooh, shiney!

but i can confirm, it works, and well. i ordered the updated firmware to bring the 700 from 1.2 to 5.1 revision... more and better voices and tracking, and support for midi in should i dare to cobble it together and install it.

all this for a synth i'll likely sell down the road. i must be mad.

but i figure, if its 100% working and guaranteed, i can sleep better at nite.... errr... all day.

my 9 to 5 is pm to am lol

[Mark Hammer]

Thanks for the vote of confidence, Jimi.  The obligation is to finish the damn Hyperflange first, before I am allowed to move on to any other major repairs.  Then there is the not-so-small matter of the Heathkit TA-17 sitting on the shelf, and..... 

[pinkjimiphoton]

hahah you got this.
if *i* as a complete newb could resurrect the ludwing phase II, i know you can do this

i feel ya on projects tho.. i gotta maestro rhythm n sound g1 been sitting on my bench 5 years now waiting for me to get back to it.

[ElectricDruid]

Where did you get your spares, Jimi?

The only ones I know about are the Analog Renaissance ones, which are definitely good, but very expensive (€46+P&P):

http://www.analoguerenaissance.com/AR80017A/

Still, with the price of Junos being what it is, they're probably worth it nowadays.

[pinkjimiphoton]

https://www.ebay.com/itm/Roland-80017a-VCF-VCA-IC-Juno106-106S-HS60-MKS7-MKS30-GR700-Referbs-Tested/302664734757?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

104$ american shipped for 2, refurbed. i had to do a little work on one still, but it was worth it.

now i got two spares, too.

[pinkjimiphoton]

tom,
you can also find a set of 6 brand new workalikes for 150 shipped out there too... i forget if it was ebay or reverb, but the price blows away the analog rennaisance price.

i mean, realistically, i'm more into paying 30 a piece than a hundred for sure!!! lol

[Rob Strand]

i hope some poor bastidge who gets one of these someday finds some of this info useful.

Stuff like that is what makes the internet awesome.

[anotherjim]

I have a dysfunctional Juno-106 sitting in the basement, that I also picked up cheap. 

Jimi, you/we simply have to get that Juno going!

[pinkjimiphoton]

thats mark's juno, jimmy
sadly, all mine have been gone for years... the last juno 106 left close to 20 years ago now. i had a juno 6, 60 and 106. the 6 was my favorite actually. really easy to program and sounded amazing.

the 60 had the 80017a disease. we had to leave it plugged in and running 24-7 and often had to reload it before gigs. i think. god.

avatar was soooooo long ago now. hard to remember!!

[anotherjim]

Ah - not good to post too early in the morning -  then Mark has the challenge!

I have a Juno-6 and yes, it's an easy going monster. I was just using it to test & run-in a PA woofer replacement - Oh! that sub-oscillator and the Hold button 

[Rob Strand]

I have a Juno-6 and yes, it's an easy going monster. I was just using it to test & run-in a PA woofer replacement - Oh! that sub-oscillator and the Hold button

I remember getting a sound close to the intro of Joan Armatrading's "I'm Lucky" from a Juno.  I'm sure it's not what was used on the album but I got my jollies out of playing it just the same  .

[Ry]

I love the simplicity and utilitarian nature of the Juno line.  I wish the 106 had the arpeggio function that the 60 does, but they are both perfect for me as a guitar player who needs synth sounds to fill out demos.  I've played with much more complicated synths and realized that I'm too dumb to use them...

Listening to the first Rentals album made me realize how versatile they are. 

[Ry]

and off topic for Jimi...I found a Ludwig Phase II for a surprisingly reasonable price.  It was always my holy grail of pedals and really the last one I built.  It needs some love to sound as good as the clone we (mostly you) worked so hard on...and I'm terrified to open it after reading your experiences with wires constantly breaking.

[ElectricDruid]

I love the simplicity and utilitarian nature of the Juno line.  I wish the 106 had the arpeggio function that the 60 does, but they are both perfect for me as a guitar player who needs synth sounds to fill out demos.  I've played with much more complicated synths and realized that I'm too dumb to use them...

Listening to the first Rentals album made me realize how versatile they are.

+1 agree. Roland had a knack for designing simple stuff (which is arguably harder than designing complicated stuff). The SH101 is also a very simple synth, but it does 90% of what you might want, and it does it really well and very easily. The control ranges are set up so that it's virtually impossible to get a bad sound out of it. Great synths, despite all their limitations - and that's not easy to pull off.

[snk]

+1 agree. Roland had a knack for designing simple stuff (which is arguably harder than designing complicated stuff). The SH101 is also a very simple synth, but it does 90% of what you might want, and it does it really well and very easily. The control ranges are set up so that it's virtually impossible to get a bad sound out of it. Great synths, despite all their limitations - and that's not easy to pull off.

I agree. Good example with the SH101.
It's quite mindblowing to compare how good it sound (like the Junos, it never sounds bad, it is an inifinte sweet spot), compared to the "not-so-appealing" featureset.

[pinkjimiphoton]

the sh101 was cool, the first "strap on".... but it was a mono synth if i recall correctly. i sold mine about about 5 years ago finally. lotta fun. but it was more of a mono analog as i recall, the juno was way better