someone upped this on "another" forum...worth a look!!!!!

[twabelljr]

i traded this off in 78, and it came back to me 33 years later, broken. now it's slowly coming back to life.

It is incredibly awesome that you started this thread with the hopes of making it possible for you and others to clone this machine and you actually got your original unit back, and another member was also able to obtain one! Thanks to everone putting so much effort into making this original idea come so close to being possible. The clones are not far away. Again, congrats on getting YOUR actual unit back. Must be a great feeling, I'm happy for you. 

[digi2t]

HEY.... I think there is a treble boost circuit in this sucker!!!!!!!!!!

On the motherboard side of things, connection #6 is labeled as going to the Bypass switch. Before the wire reaches the switch though, it goes through a turret board that's bolted in a corner of the base, with a 2 resistor / cap / tranny arrangement. Looks awful like a treble booster. That would explain why the signal is so bright when not in Bypass, but with nothing else on (Animation or Fuzz).

Worse thing is that it's not on the schematic, or layout. Crazy f*%kers!!!!!!!!!!!!!

Priliminary wire tracing. There is a 10 conductor cable that runs from the lower motherboard end of things, through the tranny box, and up to the control board end. The wires that interconnect the two boards are numbered on the drawings, and represented by hexagon symbols. So far (on my unit), wire 2 is Orange, wire 4 is Blue, wire 7 is Yellow, wire 8 is Brown, and wire 10 is Green. The last one is especially retarded, because there a three green wires in this cable  . This just reinforces the fact that I'll have to do a wire by wire, point to point survey. It will be the only way to really nail down where evrything is going.

Now... PLAY BALL!!!!

[pinkjimiphoton]

OMAFUGGINGAWDDUUUUUUUUUUUUUUUUUUUUUUUUUUUDE!!!!

sweet!! i will get at it today after the little woman leaves, so i can make some noise without listening to the bitchen.


oh yah, i forgot...there used to be a big rubber stop by the heel of the board, huh? man...time flies, i forgot all about it!!


more later!

[Morocotopo]

Guys, to all involved,you´re doing a great job of resurrecting this thing. I saw the video someone posted on youtube, and it really does some iinteresting things. Now, with no intention of hacking the post or minimizing your work, woudn´t it be nice to make a modern parts/schem equivalent of this thing? I understand the desire to make a clone as close as possible to the original,but I personally am more attracted to the idea of understanding how this works and making a functionally equivalent thing. And smaller!!

Just an idea. I think R.G. posted something along this line of thought, using OTAs or similar...

[pinkjimiphoton]

well, we don't wanna f' up one of the originals, that's why we need to clone it first...

then the next step logically will be minituarization and modernization as well. ultimately, with r.g.'s help among others, we should be able to create
a work/soundalike that will be a lot smaller. that is indeed the plan!!

but like anything, once we get the clones, which will be a humongous job, then we need to start prototyping to get the end result.

stay tuned....peace!

[pinkjimiphoton]

some bad news, in a way....
my girl went out, so i immediately hooked up the pedal to the closest amp and started messing with it. before this, i had only tried it thru a boss gt5 with headphones on.

wellp, thru an amp, it sounds nothing like dino's...more like a fuzz wah, the formants work, but are more in the background than actually processing the guitar signal.
everything works, but it developed a hum a couple minutes in, and as i played with it, the hum got worse...and worse.

so i turned it off, tried different cords, and same thing...only it started to get WORSE. and quickly!!!! so i shut her down, knowing in my dimwitted fashion from tube amps that a worsening hum = bad electrolytic, and one getting ready to blow. bummer.

so...for right now, i won't be able to supply any voltage information, and see no point in trying to tweak the trimmers to the levels dino suggested...i gotta bite the bullet, and am gonna strip her down and replace ALL THE ELECTROLYTIC CAPS, PRONTO.


hopefully that will cure it, then i can put it back together and re-calibrate it and with luck, and no bad solder (shudder) she'll be rockin and rollin' again.

only prob is i don't know how much it's gonna cost for the caps...looks like i'll be needing to put it on plastic (yay) and make a big order from mouser or allied.

gonna check the schematics for the values, hopefully they are right. but now i'm gonna have to dissassemble the entire unit...so i'll fix the broken fuzz repeat slider and replace the lamp for the fuzz switch too. sh** happens, i was hoping to not have to do major surgery, but at this point i guess it's unavoidable. gotta be done!!!

so...tho woe is me, it's probably ultimately all right, as then the unit will be good for probably the rest of its/my life.

dino...if ya get a chance, can you see what the value is on the slide pot for the fuzz repeat?
also...i DID get a thumping sound from the fuzz repeat thru the amp, so i'm imagining that you may wanna replace the electrolytics in yours too to see if that cures it...or, wait til i do to see if that's actually the issue.

bummer. i was planning on rockin' the hell out of this thing today!!! lol...

[pinkjimiphoton]

if someone would be so kind as to check the schematic for me to see if i got this right, i'd appreciate it.
i'm assuming the ceramic and film caps will be ok, so am going to buy the electrolytics today at cables and connectors .

here's what i got from looking at the schematic:

bottom board

c 1 10mf@25v
c 13 10mf@25v
c 14 25mf@25v
c 15 10mf@25v
c  21 10mf@25v
c 22 25mf@25v
c 23 25mf@25v
c24 10mf@25v
c 31 10mf@25v
c 32 25mf@25v

top board

c1 25mf@25v
c6 1mf@25v
c8 100mf@25v
c9 10mf@25v
c10 10mf@25v
c11 100mf@25v
c11 100mf@25v
c12 50mf@25v

i'm gonna go with 35 or 50 volt caps for safety, as i see that it's running off a 35 volt supply, and has a couple diodes marked as 35 volts, too.

dumb newbe question, but...do i need to replace the diodes too?
after i replace the caps, do i need to fire it up slowly with a variac? i don't have one anymore, but i do have a lighting dimmer.
not sure if the caps have to "form"...i do NOT wanna mess this thing up any worse!!!!!!!


please help...thank you from me and karma!!

[R.G.]

HEY.... I think there is a treble boost circuit in this sucker!!!!!!!!!!

On the motherboard side of things, connection #6 is labeled as going to the Bypass switch. Before the wire reaches the switch though, it goes through a turret board that's bolted in a corner of the base, with a 2 resistor / cap / tranny arrangement. Looks awful like a treble booster. That would explain why the signal is so bright when not in Bypass, but with nothing else on (Animation or Fuzz).

Worse thing is that it's not on the schematic, or layout.

I did have an email that referred to the "mystery buffer circuit" at one time.

but it developed a hum a couple minutes in, and as i played with it, the hum got worse...and worse.
... gonna strip her down and replace ALL THE ELECTROLYTIC CAPS, PRONTO.

hopefully that will cure it, then i can put it back together and re-calibrate it and with luck, and no bad solder (shudder) she'll be rockin and rollin' again.

Just replacing the electros will not require recalibration. They have no effect on the DC conditions unless they're bad, and the trimpots are all DC conditions.

only prob is i don't know how much it's gonna cost for the caps...gonna check the schematics for the values, hopefully they are right.

No biggie. Few bucks. It's almost certainly the main power supply filter that's causing the hum, but you're right - replace them all. If money is a consideration, think about using radial-package caps instead of axial. Radials are used in much greater quantity and so are cheaper per value.

Also, don't sweat the schematic values for the caps too much. Back when this was made, tolerances on electros was usually +80%/-20%. So pick the nearest standard size and go with it. For instance, there are (at least) four 2.5uF caps on the schemo. Use 2.2uF, which is readily available. The electros in this do not have a big effect on tone as long as they're not leaky or too small.

Glad to see you jumped to the right conclusion. You may want to read "resuscitating the elderly pedal" at geofex, from 2000.
http://geofex.com/fxdebug/geriatric.htm

[pinkjimiphoton]

thanks rg...but which caps were 2.5? i saw 25, but like i said, my eyes are dodgy...i went over it three times but i saw it as 25, not 2.5...appreciate the help bro!!!
if you can just tell me which caps...say, c5 or c13 or whatever, i'd appreciate it.

going to geofex to read now. thank you!!

[pinkjimiphoton]

i just enlarged the schems ridiculously, but still can't see the dif between 2.5 and 25....and that's probably a huge enough issue to make a problem with replacement.

i really really appreciate the help, i hate to ask, but i really just can't see it. are they on both boards?

this is what i had seen, again:

bottom board

c 1 10mf@25v
c 13 10mf@25v
c 14 25mf@25v
c 15 10mf@25v
c  21 10mf@25v
c 22 25mf@25v
c 23 25mf@25v
c24 10mf@25v
c 31 10mf@25v
c 32 25mf@25v

top board

c1 25mf@25v
c6 1mf@25v
c8 100mf@25v
c9 10mf@25v
c10 10mf@25v
c11 100mf@25v
c11 100mf@25v
c12 50mf@25v

if you could add a couple dots, i'd appreciate it incredibly!!

getting ready to open the top panel up...figure if i gotta be in there anyways, i may as well measure the resistance of the broken slider, get it's physical dimensions, and pull the blown bulb as well so i can read the voltage and get a replacement.

thanks!

[pinkjimiphoton]

ok, i figured since there's only like 5 caps in total that i thought were 25mf, i blew the schematics up about 7x the original size...

i still can barely tell, but it appears that on the bottom board, c14, 22,23 and 32 are ALL 2.5mfd, and on the top board, c1 is also 2.5mfd.

thanks r.g., without you i would have probably messed up heinously!!

so here's an updated and hopefully right BOM for the electrolytic caps:

bottom board

c 1 10mf@25v
c 13 10mf@25v
c 14 2.5mf@25v
c 15 10mf@25v
c  21 10mf@25v
c 22 2.5mf@25v
c 23 2.5mf@25v
c24 10mf@25v
c 31 10mf@25v
c 32 2.5mf@25v

top board

c1 2.5mf@25v
c6 1mf@25v
c8 100mf@25v
c9 10mf@25v
c10 10mf@25v
c11 100mf@25v
c11 100mf@25v
c12 50mf@25v

[R.G.]

i'm assuming the ceramic and film caps will be ok, so am going to buy the electrolytics today at cables and connectors .

ceramic and film caps will almost certainly be OK. It would be unusual if they were bad.

here's what i got from looking at the schematic:

Looks OK, but you listed C11 twice. No biggie.

i'm gonna go with 35 or 50 volt caps for safety, as i see that it's running off a 35 volt supply, and has a couple diodes marked as 35 volts, too.

Good choice. I wouldn't use less than 35V. 50 would be a better choice for C8 and C11. 35V will be marginal for those.

dumb newbe question, but...do i need to replace the diodes too?

Probably not. Diodes should be well under $0.10 each for 1N4004 through 1N4007. Any of those should replace any of the diodes on the board well enough. You need diodes with over 70V revers rating, so anything rated for 100V on up works OK. Don't mess with D3 (36V zener diode) until you've replaced electros and metered the supply voltage to see that it's nearly 35V. Chances are it's fine.

after i replace the caps, do i need to fire it up slowly with a variac?

Not unless you buy really old stock, surplus caps. Generally it's only the high voltage electros in tube amps that need this.

Just for some comparisons, from Mouser:
1 - 1uF / 50V: axial, $0.25 to $0.50 each; radial $0.05 to $0.10 each;
8 - 10uf@50v: axial $0.25 to $0.50 each  ; radial $0.04 to $0.08 each
5 - 22uf@35-50v: axial $0.35 to $2.50 each  ; radial $0.04 to $0.08 each
1 - 47mf@35v-50v: axial $0.25 to $0.50 each  ; radial $0.04 to $0.08 each
3 - 100mf@50v: axial $0.30 to $1.00 each  ; radial $0.06 to $0.20 each

So mail ordering from Mouser, you'd pay a minimum of $5.15 for all axials, and a minimum of $0.79 for all radials.

[pinkjimiphoton]

thanks again for the info r.g....i'm figuring i'll save the wait and hit the local store, i can get the whole lot for probably 15 bucks...well worth it to not have to wait!

soon as i get done typing, i'll crack open the top half...hopefully not break anything!! gonna put numbers next to each connection wire and the color, so if i break anything i can backtrack easily.

thanks for all the help!!! 

[R.G.]

soon as i get done typing, i'll crack open the top half...hopefully not break anything!! gonna put numbers next to each connection wire and the color, so if i break anything i can backtrack easily.

I find it very helpful to take a bunch of digital pictures as I disassemble things. Then if I don't need them later, I can just flush the pics, they're worthless. But if I need them, they suddenly become worth their weight in gold.

[pinkjimiphoton]

great tip! my camera is already by my side...not sure how to dissassemble it tho, looks like i have to undo it from the underside of the case.
there's a couple screws on top too, time to get my hands dirty!

[pinkjimiphoton]

ok, some disassembly notes for future generations. the pull knob that lets the pedalboard be lowered unscrews to the left, standard thread kinda thing.

there are two screws that hold the top marker plate on. and two screws below the top assembly that remove a plate that covers the underside of the top.

carefully remove the bundled wires in the right inside of the case.

unscrew the 4 small screws on the outside corners on the top of the assembly, and you can then lift out the entire top assembly.

the small incandescent screw in bulbs for the switches can be released by gently pulling down on a brass clip that holds them in place. the color changes are from small pieces of colored gel that are mounted to the chassis below the transparent switches.

the sliders are mounted to a sub-chassis metal plate...i'm gonna take notes as to their wiring etc so i can dis-connect the broken slider...that i may have to order if the local guys don't have an equivalent...i know they have SOME old stock slide pots, i'm gambling on them being able to have one to replace, i'll bring it with me.

so..at this point, that's where i'm at...spelunking into the past, and with luck, i'll be successful matching the broken parts.

more later. will also up more pics in a minute or three. peace.

[pinkjimiphoton]

photobucket is screing up, so there may be a dupe pic or two...sorry!!



















also....voltages i posted were wrong, and i missed c2

top board

c1 2.5mf@25v
c2 1mf@25v
c6 1mf@25v
c8 100mf@40v .....50v
c9 10mf@35v .......50v
c10 10mf@35v ......50v
c11 100mf@65v ....100v
c12 50mf@40v  .....50v

gonna crack the bottom back open so i can be sure of voltages on the caps.

[R.G.]

You're probably OK with 63V (next standard value up from 50V) on C11.

[pinkjimiphoton]

c 11 is marked on the pcb as 100mf@65, that's why i figure i'd go with 100v r.g..

[R.G.]

Makes sense, but I suspect that the difference between 63 and 65 isn't going to mess you up. Get 100V if you can, use 63 if they don't have 100.

I would guess that the actual voltage on the cap is between 45Vdc and 60Vdc, and most likely about 50Vdc, just from looking at the circuits.

You could ice this one up solid by measuring the voltage on the output of the transformer after pulling the transformer contacts off the board and measuring between them with an AC reading meter. The peak DC will be half of the end-to-end transformer voltage times 1.414.