ovation fuzz from the late 60's/// help me resurrect it?

[pinkjimiphoton]

well, since the super bowl is on and i have a superior bol i'm far more interested in, when i get done typig this, gonna start the herculean task of writing connections down. its not as bad as it seems, cuz of the modularity.

btw, the blue wire on the fuzz board goes to the input of the channel 2 volume pot, which is stacked.

the fuzz switch just shorts to ground. i won't try to remember which colors are which yet, wanna write all that crap down while i'm looking at it.

so i'm guessing the batch of transistors they got was too low a beta for the job, so they tried to bias it.

once we get the voltages and connections, i'm imagining pretty much any q will make it fire.  but still, its the most likely thing to go wrong with the dang board! its the only semi on there!

we'll see. if i'm up to it i'll go for voltages tonite too. it only takes a few minutes to reassemble the sucker. they got THAT part right at least.

betcha they said screw it, it passes signal.... friday job

[Rob Strand]

onna start the herculean task of writing connections down. its not as bad as it seems, cuz of the modularity.

After all the poking around you will know the lie of land.

btw, the blue wire on the fuzz board goes to the input of the channel 2 volume pot, which is stacked.

OK so it's pretty hard bolted into channel 2.

the fuzz switch just shorts to ground. i won't try to remember which colors are which yet, wanna write all that crap down while i'm looking at it.

Yep,  I capture that in last Fuzz pic, but not the colors.

so i'm guessing the batch of transistors they got was too low a beta for the job, so they tried to bias it.

once we get the voltages and connections, i'm imagining pretty much any q will make it fire.  but still, its the most likely thing to go wrong with the dang board! its the only semi on there!

we'll see. if i'm up to it i'll go for voltages tonite too. it only takes a few minutes to reassemble the sucker. they got THAT part right at least.

betcha they said screw it, it passes signal.... friday job

Yes, might have got under the radar from something like that.  The transistor could have been flakey from day 1.

One thing I find funny is the whole motivation behind the product was to have this robust fault-tolerant design, but the mixer, which connects to the evil outside world was excluded and didn't get any extra protection.   It's like those half-baked government policies.

[pinkjimiphoton]

most especially that last line.

yeah, why make it bullerproof and give it a huge achilles heel?

gonna grab some grub and down i go
there i go, there i go

there
i
go

lol

[Rob Strand]

I just noticed something.   The last stage of the Fuzz is very much like the unmodified mixer (ie. no parallel R's and no bridge).    The emitter resistor value might be different.    I can't quite see the value clearly on the mixer pics.   It doesn't look the same value as the Fuzz.   IIRC it didn't make a big impact on the biasing (because the 33k goes across b and e instead of the usual b and ground).

[pinkjimiphoton]

robbro
i didn't trace EVERYThing...

but i DID get a LOT of notes, including what from what socket connects to what for all the boards.
also got voltages for the mixer and the fuzz.

looks like most of the fuzz board isn't even used. we may be able to fix that.

the mixer stage voltages are weird as hell
the b+ is about 22 volts, it was swinging between about 21- 22.. at the power  supply appears to start as 25vdc

anyways, the transistor in the mixer reads like this

C   10.75
b      .56
e       0

seems to me, the voltage at b should be higher, c, too, probably. i wonder if they fudged it with a lower voltage q than they should have used. this was mos def def def a friday afternoon job... like, 4:30, and its the 60's, and you have run out of reasons to run to the bathroom every 15 minutes, and gotta get up and went so who cares if a pos gets thru?

lol.. i am i think gonna scan stuff. its probably easier than trying to type it all.
that way, drawings, notes etc are there.

i am not sure on the power supply yet, i have to give it a hard look. it uses some kind of terminal blocks i've never seen before to distribute power everywhere, and there's one on both sides of where the power filter caps are.

also, i blew up the circuit breaker, ooops. meter probe slipped. took me about 10 minutes to figure out wtf was wrong. jumpered it . back to life, pretty much the same as it was.
i'm thinking i wanna remove that solder bridge tomorrow and see if that b voltage comes up, i'm betting it does.

btw... no fuses in the damn thing, just the circuit breaker i broke breaking stuff.

its gonna be messy. i will try to translate as best i can, and forgive my febrile scrawl, never was much of a penmanship dude. chicken scratch may be more legible.

i think you'll be able to finger it out.
be back shortly with a mess-o-scans

[Rob Strand]

i didn't trace EVERYThing...

but i DID get a LOT of notes, including what from what socket connects to what for all the boards.
also got voltages for the mixer and the fuzz.

No problem.   Whatever you can do is OK with me.

looks like most of the fuzz board isn't even used. we may be able to fix that.

Is the board going to grow to the size of the enclosure 

the mixer stage voltages are weird as hell
the b+ is about 22 volts, it was swinging between about 21- 22.. at the power  supply appears to start as 25vdc

anyways, the transistor in the mixer reads like this

C   10.75
b      .56
e       0

seems to me, the voltage at b should be higher, c, too, probably. i wonder if they fudged it with a lower voltage q than they should have used. this was mos def def def a friday afternoon job... like, 4:30, and its the 60's, and you have run out of reasons to run to the bathroom every 15 minutes, and gotta get up and went so who cares if a pos gets thru?

Somehow I screw up my bias circuit before.   I was wait until we pin down the voltages before I fixed it.

To me the base looks OK-ish.   If it's a larger transistor running at lot current that's fine.  Like if it was 600mV at 1mA collector current it would be perfectly normal to get 0.54V at 100uA collector current.

With the mixer part values as is I get Vc= 14.2V for the 2N3904 and 11.1V for the 2N2222.   Your voltage isn't too far off the 2N2222 so maybe OK.    So what the hell's going on with that thing!   

[BTW, with the mods taken out I get 9.7V for the 2N3904 and 8.6V for the 2N2222.    That's with an emitter resistor of 22k, which don't know is correct yet.]

When you measured the mixer voltage did you measure the solder part of the pins or the actual parts on the pcb?   It crossed my mind maybe the edge-connector could have bad connections.   That would cause also sort of weird behaviour.

also, i blew up the circuit breaker, ooops. meter probe slipped. took me about 10 minutes to figure out wtf was wrong. jumpered it . back to life, pretty much the same as it was.

Ouch.

its gonna be messy. i will try to translate as best i can, and forgive my febrile scrawl, never was much of a penmanship dude. chicken scratch may be more legible.

think you'll be able to finger it out.
be back shortly with a mess-o-scans

My writing is pretty bad too.  When I was in overseas people in the hotel asked me what language is that  .   A friend of mine is even worse.

Whenever you get time.

Do you have an oscillator or and/or an oscilloscope?     I wonder if we can measure the gain of the mixer stage.   Not sure what to think after your mixer measurements.

[pinkjimiphoton]

sadly i done run outta jam for the nite.
i will scan all the stuff tomorrow. i measured voltage at every pin of every socket on all the boards.
also wrote what connects to where. its gonna be confusing but about 80% of the circuit is actually traced other than a couple of wires to the trem switches and the power supply.

there's 8 pages of connections i wrote out.
i wrote which number of each socket, what wire goes where, what color for every one of 'em
both channels
the fuzz, reverb, tuner, trem and mixer board.

it REALLY seems like that mixer board needs more freekin gain. it can't compete with the channel 2 only output.  and it appears to be just what it is... a buffer stage, right? or a gain stage? what ever, it needs more ... ummm... "intestinal fortitude " for sure. lol

anyways... more tomorrow bro. thanks for takin the cruise with me.

[Rob Strand]

I just did some playing around on the simulator.

I also did some pondering.   One thing which can affect the gain of the mixer is the reverb board.
So maybe you should check the gain with the reverb board out.

Assuming the output impedance of channel 1 or channel 2 looks like about 100k  (a total guess) the gain of the mixer as a whole *without the reverb board* is about unity.   Within +1dB and -2dB  depending on the transistor.

With reverb in the gain drops about 1dB

With the resistor mods removed and the solder bridge removed the gain is really low.  -14dB with the all the mods in and -25dB with the mods out.

So it seems the mods are required to ensure the overall gain of the mixer is unity.

That also means the BOTH jack and the CH2 Only jacks should produce about the same level.  However we know they don't.

So I was thinking maybe the reverb board is stuffed?  That could load down the input to the mixer (via the purple wire on pin 1) 

Can you do a level test with the Reverb board pulled?

[Rob Strand]

sadly i done run outta jam for the nite.

You can only do what you can.  No hurry.

I posted another post just a second ago.

[pinkjimiphoton]

I just did some playing around on the simulator.

I also did some pondering.   One thing which can affect the gain of the mixer is the reverb board.
So maybe you should check the gain with the reverb board out.

Assuming the output impedance of channel 1 or channel 2 looks like about 100k  (a total guess) the gain of the mixer as a whole *without the reverb board* is about unity.   Within +1dB and -2dB  depending on the transistor.

With reverb in the gain drops about 1dB

With the resistor mods removed and the solder bridge removed the gain is really low.  -14dB with the all the mods in and -25dB with the mods out.

So it seems the mods are required to ensure the overall gain of the mixer is unity.

That also means the BOTH jack and the CH2 Only jacks should produce about the same level.  However we know they don't.

So I was thinking maybe the reverb board is stuffed?  That could load down the input to the mixer (via the purple wire on pin 1) 

Can you do a level test with the Reverb board pulled?

no output change with the reverb board pulled. that was one of the first things i tried.

[pinkjimiphoton]

ok, as promised, the results of last nite's tracing of the sockets, etc

chan 1 socket, 18 pins


chan 2 socket, 18 pins



fuzz socket, 12 pins



mixer connections... did i mention its the only one of the "switches" designed to come off?yeah... fudgepackers!! lol



pot and rocker switch values, volume pots are dual stacked, fuzz pot has on/off switch at "zero"



reverb socket




trem board socket


tuner socket



voltage readings



hopefully will answer a couple questions, and make it easier for the theoretical future man to build one lol

[Rob Strand]

no output change with the reverb board pulled. that was one of the first things i tried.

Even more puzzling.  BTW, I actually screwed up on the level drop with the reverb board in; I must be getting tired too  .

The problem must be somewhere in the mixer.    I just can't see what the problem is.    What about the input or output caps?  Normally I wouldn't expect problems with those.

[Rob Strand]

ok, as promised, the results of last nite's tracing of the sockets, etc

Wow! dude!  that's a lot of stuff to get down.   Might take a while for me to process it all.
Infinitely better than poking around for clues on the random gut shots.

[pinkjimiphoton]

HAHAHAHAH sorry to inundate you bro!!
but yeah, definitely in the mixer, and a shitty design.
since the b+ is only 25 v, should be able to find a replacement for the tranny if need be,
it COULD be the caps, but seems unlikely.
i think they were just too high on coke or did too many shrooms when they designed it.
i'm gonna try and undo the blob and mods and see if the volume comes up. if it does, cool, if not, i guess next step is continuity point to point, and then replacing each component on the mixer board.
i may hack an lpb1 or something similar into it to get the gain up on the summed outputs.
but i suspect the volume discrepancy is from the design... i mean, no reverb on channel two by itself, the switch is what connects the bloody reverb on the channel 2 only output.

i think they didn't think this thru all the way. we'll see!
let me know if there's any other info needed, and i will do my best to get it done.

gotta go spend some breadboard time... i recently gotta gig designing fuzzboxes for a company in georgia! diggin it!
one of the few things i seem to be any good at lol
talk soon brother... peace!

yeah, took me from 8:00 pm last nite til 1:30 or so am to get all that shit traced. as ya can see, i had a few false positives i had to ammend, too... some of it was kinda tricky to see!

i went with numbering for the sockets left to right, but the keyways in each board will tell ya if i got the alignment correct, sorry, i may have got some stuff mirrored inadvertantly.
i wanted to do it with the boards in place, but it was impossible to see everything.
i believe what i posted earlier is deadnuts right.

[Rob Strand]

HAHAHAHAH sorry to inundate you bro!!

Yeah, I can't keep up now.  I looked over the preamp this morning.   All the connections makes my head hurt a bit but at the end of the day it's kind of a James tone control ("Passive Baxandall").   And yep the tremolo modulates the gain of one of the stages - a bit like the EA Tremolo but with a vactrol instead of a JFET.

i'm gonna try and undo the blob and mods and see if the volume comes up. if it does, cool, if not, i guess next step is continuity point to point, and then replacing each component on the mixer board.

Maybe just try it.  The more I look at it the less I think that will fix it.

The weird thing is "Channel 2 Only" output is at the right level.   Also when I simulated the mixer it should pretty much give a gain of 1 from either channel to the "Both Output".   So that means *channel 2* at least should come through at the same level as "Channel 2 Only".     Pulling the reverb and tremollo don't affect or fix the problem so it's not those.   It really need a signal generator up it's clacker and an Oscilloscope to find where the signal is being lost.

One question:  When you use the "Both Outputs" is Channel 1 and Channel 2 more or less the same level?  When listen to channel 1 make sure channel 2 is turned right down, and when listening to channel 2 make sure channel 1 is turned right down.

i think they didn't think this thru all the way. we'll see!

Maybe not.   I need to piece that stuff you posted together.

One thing I keep thinking is the mixer inverts the signal.   In Separate Mode channel 2 goes straight out the "Channel 2 only" connector.   However Channel 1 goes through the mixer which inverts channel 1.  So does that mean Channel 1 and Channel 2 cancel each other in Separate Mode.   if they don't then does that mean Channel 1 and Channel 2 cancel each other in "Parallel Mode"?

There's something whacked with this set-up.

yeah, took me from 8:00 pm last nite til 1:30 or so am to get all that shit traced. as ya can see, i had a few false positives i had to ammend, too... some of it was kinda tricky to see!

Sometimes that stuff sends your head spinning.   The later it gets the blurrier you eyes and fuzzier your mind and you keep having to back track over stuff because you make mistakes.

went with numbering for the sockets left to right, but the keyways in each board will tell ya if i got the alignment correct, sorry, i may have got some stuff mirrored inadvertantly.

Yes.  I noticed that.  No big deal I don't know if we should just flip the numbering now instead of carrying it through to the schematics.    Not a big deal provide we make a note of it.

[pinkjimiphoton]

dude... i got it. ITS ALIVE

and WICKED loud. the reverb is studio quality and pretty much to die for.
the fuzz on its own is horrid, BUT

if you were say to use, like a fuzzface, or an octavia, or a super hot rodded big muff pi with a three band active eq grafted in where the tone stack used to be, its absolutely killer.

like.. imagine an extra gain stage of treble boosted fuzz. its sickening, its stomach turning, i gotta send the schematic to dave at lucifer's trip to add to the collection, he'll love it.
holy shit. makes it just cut right thru everything, real nice sustain, total sizzle
and with the reverb even better.
i got my princeton volume OFF and the preamps up a fair amount, and its loud enough for my girlfriend too bitch lol.. always a good sign.
so i'm gonna kinda HAVE to trace the rest of it out, for posterity, i think, including the values n stuff where i can get them. its actually just as cool as i remember.
now that i think of it, what i loved so much about it was the way it worked with my UMI buzztone and expander, really brought the guitar to life with some sizzle into a vox solid state combo... a 2 x 12 verticle bass combo that sat in this cool little baby perambulator lookin contraption. it had no reverb, no balls really. but man, with this thing and that buzztone crankin
#FuzzyGoodness

sick.

so i disconnected the bottom bias resistor at ground. definitely a factory thing, i think they f'd up the circuit board there, no trace from e to ground. what they did was solder the southern end of the resistor first to e, then jumpered the whole thing to the adjacent ground trace.
disconnecting it had a very minor effect on the circuit, it just got noisier and a bit gainier...
i put it back together seeing no particular improvement.
i also took voltages, c 10.1, b .5, e 0. same as last nite.

so jack darr comes in, and saves the day yet again from the shades.

circuit disturbance test. time to whack the bejesus outta each component and see what happens.

whacked it with a probe. just IT. the board.
ROAAAAAAAAAAAR goes my amp.
hmm.
curious.

so i whacked the first big cap closest to me, it roars again, but obviously ain't the problem

so i wacked the second big cap, the .47u output... KERANNNNNGGGGG goes my amp. soon as i take the meter off, dead.

turned it off, let it discharge, reflowed the cap with some fresh old school possibly illegal solder
and popped it on.

i had sound.. equal between the two preamps.
preamp ONE is louder than two slightly. the slot is.
turns out, preamp board one was actually preamp board TWO.
a little bassier, drives the fuzz better. so i swapped them.

now channel one is a little louder when both channels are used,
channel two has fuzz, none on channel one <unless ya jumper the channels, which ya KNOW i did> (')
reverb works on both channels, as does top boosts, and tremolos
channel two output and paralleled output now equal in volume
it was the damn output cap... of course
must've took a good hit in transit.
channel two only has fuzz but no reverb. as its supposed to be in the catalog.
i'll try and get some video of the beast.

i think they figured every self-respecting professional guitarist would have a fuzzbox already they played thru at the time.. so they made theres a fuzz helper, footswitchable for a lead boost that really actually WORKS.
i'm re-impressed.

so, ya got your tonebenderface on, ya turn your guitar up n down, and kick this on when ya need to burn. pretty cool for 1969 tech!

the tone shaping possibilities are hip. i can't wait to put my studio back up and do some old school analog recordings... ummm,. digitally, like i used to do.

this thing and the ludwig and an echoplex and a few choice fuzzes could be a ticket to nelvana-ish bellybutton window gazing. its hip. its now. its 50 @#$%ing years ago. wtf lol

so... should we go all the way for it, or what?

btw, the strobe tuner thing actually works freeking great and is a trip to play with.
cranked up its an in tune G, third fret of the high e string.
you can tune it downward to almost any other note. if ya tune it to where e is, you can downtune it with the knob and do the sounds before "jet airliner" by steve miller. just add highly regenerative echoplex and maybe a moog on the side

let me know how far ya dare go. i'm willing to gather data, but it may be a major pain in the ass.

i am toying with the idea of maybe changing them little caps in the fuzz circuit to give it more ass

i bet going from 1n to 100n will be a substantial improvement in the fuzz tone, but it may ruin the function described earlier i am pretty sure it was designed to do.


maybe a switch somewhere 

i'm gonna have to disassemble the entire switching rack to put the mixer and reverb switches back on, we've already got most of it, so all thats left really is a couple of the wires on the switches, and the power supply.

shoot, we don't even really NEED the power supply. most of the boards run at either 10 volts... could run 'em at 9 and i doubt they'd blink.... or 21.... run 'em at 17v with a charge pump, or step it up to one of them 24v transformers and regulate it down to 21 and 10 volts.
a modern power supply would probably actually be an improvement to the original design, you can put the transformer farther away from the unit.
i'm surprised how quiet the unit actually is, considering.

i dunno. madness. MADNESS, i tell you...
but this thing is actually kinda freekin hip!!!

gonna have to figure out the wiring for the footswitch, i know its a 6 pin din and the footswitch had three buttons, fuzz, reverb, and tremolo. should be fairly easy to do

man. thanks so much for all the help, dude. you freekin rock, rob!

anyways... let me know whatcha wanna do, and if there's info needed i am missing.
i can get resistor values, caps, etc etc and better detail on things.
just lemme know

peace out







(') the crux of the biscuit is the apostrophe..... ps... forgot... jumper channel one to channel two? not only puts the channels in parallel, but you can use channel one to overdrive @#$%ing channel two. sick. SICK!!!!!!!!!!!!!!!!!!!!

[Rob Strand]

dude... i got it. ITS ALIVE

and WICKED loud. the reverb is studio quality and pretty much to die for.
the fuzz on its own is horrid, BUT

Freak awesome!

its loud enough for my girlfriend too bitch lol.. always a good sign.

Indeed 

so jack darr comes in, and saves the day yet again from the shades.

circuit disturbance test. time to whack the bejesus outta each component and see what happens.

whacked it with a probe. just IT. the board.
ROAAAAAAAAAAAR goes my amp.

Excellent - when all else fails kick it!

so i wacked the second big cap, the .47u output... KERANNNNNGGGGG goes my amp. soon as i take the meter off, dead.

... I can smell the blood ...

it was the damn output cap... of course
must've took a good hit in transit.

It always turns out to be the last thing on the list for shitty problems like this.

now channel one is a little louder when both channels are used,
channel two has fuzz, none on channel one

There's something in the manual about ch1 being louder than ch2 in one of the modes.
That's a good sign, means it really *is* working like a bought one.

so, ya got your tonebenderface on, ya turn your guitar up n down, and kick this on when ya need to burn. pretty cool for 1969 tech!

the tone shaping possibilities are hip. i can't wait to put my studio back up and do some old school analog recordings... ummm,. digitally, like i used to do.

this thing and the ludwig and an echoplex and a few choice fuzzes could be a ticket to nelvana-ish bellybutton window gazing. its hip. its now. its 50 @#$%ing years ago. wtf lol

Finally some fun after all the screwing around.

"nelvana-ish bellybutton window gazing"  where did that come from.

btw, the strobe tuner thing actually works freeking great and is a trip to play with.

Cool.

i bet going from 1n to 100n will be a substantial improvement in the fuzz tone, but it may ruin the function described earlier i am pretty sure it was designed to do.

maybe a switch somewhere 

I had a feeling you were going to mod it.  Especially those caps.

i'm gonna have to disassemble the entire switching rack to put the mixer and reverb switches back on, we've already got most of it, so all thats left really is a couple of the wires on the switches, and the power supply.

If you want to clean-up a few things that's find.
BTW, what reverb tank does it use?    The circuit looks like it can only handle a very high impedance drive coil.

i dunno. madness. MADNESS, i tell you...
but this thing is actually kinda freekin hip!!!

gonna have to figure out the wiring for the footswitch, i know its a 6 pin din and the footswitch had three buttons, fuzz, reverb, and tremolo. should be fairly easy to do

man. thanks so much for all the help, dude. you freekin rock, rob!

No problem at all.  I'm really happy it finally got up and sang.

anyways... let me know whatcha wanna do, and if there's info needed i am missing.
i can get resistor values, caps, etc etc and better detail on things.
just lemme know

Well today I poked around with the preamps.  Sooo many connections.   Your reverse mixer numbering really messed with my brain - many translations going.   I'll have to flip a few numbers so it matches the schematic.

I'm pretty sure I will have some questions.  Like there's a few parts off the PCB which are point to point tack onto things.

Good stuff!!!

[pinkjimiphoton]

dude... i got it. ITS ALIVE

and WICKED loud. the reverb is studio quality and pretty much to die for.
the fuzz on its own is horrid, BUT

Freak awesome!

yeah boyeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee!

its loud enough for my girlfriend too bitch lol.. always a good sign.

Indeed 

so jack darr comes in, and saves the day yet again from the shades.

circuit disturbance test. time to whack the bejesus outta each component and see what happens.

whacked it with a probe. just IT. the board.
ROAAAAAAAAAAAR goes my amp.

Excellent - when all else fails kick it!

so i wacked the second big cap, the .47u output... KERANNNNNGGGGG goes my amp. soon as i take the meter off, dead.

... I can smell the blood ...

it was the damn output cap... of course
must've took a good hit in transit.

It always turns out to be the last thing on the list for shitty problems like this.[/quote]

yep, as usual, the very last @#$%ing component literally in line!! haha... but its good to know i iso'd it to that board... my powers grow!!! lol

now channel one is a little louder when both channels are used,
channel two has fuzz, none on channel one

There's something in the manual about ch1 being louder than ch2 in one of the modes.
That's a good sign, means it really *is* working like a bought one.[/quote]

yeah, i gotta get another circuit breaker, and i think i'll replace the filter caps, as its a bit noisy.  but maybe leaving it on for a couple days will help, a lot of times that will "dry out"
the moisture the cc resistors tend to absorb, and make the bacon frying and hiss go away.

so, ya got your tonebenderface on, ya turn your guitar up n down, and kick this on when ya need to burn. pretty cool for 1969 tech!

the tone shaping possibilities are hip. i can't wait to put my studio back up and do some old school analog recordings... ummm,. digitally, like i used to do.

this thing and the ludwig and an echoplex and a few choice fuzzes could be a ticket to nelvana-ish bellybutton window gazing. its hip. its now. its 50 @#$%ing years ago. wtf lol

Finally some fun after all the screwing around. [/quote]

oh hell yeah... this thing feeding my echoplex outta channel two into the wet channel of my pro reverb, and the dry channel getting the main out with reverb? be still my heart!!
i am a huge fan of multiple reverbs being on. live, i tend to run one on my board, one on top of my amp as a line driver/buffer with more reverb, and the one on my amp cranked up a fair amount. reverb narcossis? naaah... but really complex reverbs and tone? oh hells yes!

"nelvana-ish bellybutton window gazing"  where did that come from.

remember all that peyote and lsd i mentioned? well, all these years later, still "on the bus"

belly button window comes from hendrix, belly button contemplation comes from mad magazine back in the 60's raggin
on hippies, nelvana came from the old holistic harry cartoons in playboy in the late 70's and early 80's... somehow the whole mess sloshed around the abcess twixt my ears til it came out like that.

sorry? lol

btw, the strobe tuner thing actually works freeking great and is a trip to play with.

Cool.

i bet going from 1n to 100n will be a substantial improvement in the fuzz tone, but it may ruin the function described earlier i am pretty sure it was designed to do.

maybe a switch somewhere 

I had a feeling you were going to mod it.  Especially those caps.[/quote]

i AM thinking about it, but i kinda like the fuzztone as it is, as a footswitchable extra stage of madness.
i have tonnes of great fuzzes, so i think i'll leave it as is... tho i may try it modded to see how it sounds.
i still wanna resurrect it to a standalone any way we end up going!!

i'm gonna have to disassemble the entire switching rack to put the mixer and reverb switches back on, we've already got most of it, so all thats left really is a couple of the wires on the switches, and the power supply.

If you want to clean-up a few things that's find.
BTW, what reverb tank does it use?    The circuit looks like it can only handle a very high impedance drive coil.

good question, i will look for numbers on it, or try and measure it. looks like a typical accutronics tank, similar too what i see in kustoms n stuff from that era.

i dunno. madness. MADNESS, i tell you...
but this thing is actually kinda freekin hip!!!

gonna have to figure out the wiring for the footswitch, i know its a 6 pin din and the footswitch had three buttons, fuzz, reverb, and tremolo. should be fairly easy to do

man. thanks so much for all the help, dude. you freekin rock, rob!

No problem at all.  I'm really happy it finally got up and sang.

i think once its gone thru and cleaned up with some fresh can caps etc it wil really scream!

anyways... let me know whatcha wanna do, and if there's info needed i am missing.
i can get resistor values, caps, etc etc and better detail on things.
just lemme know

Well today I poked around with the preamps.  Sooo many connections.   Your reverse mixer numbering really messed with my brain - many translations going.   I'll have to flip a few numbers so it matches the schematic.

sorry, my bad. i made a conscious decision to locate pins via the keyway, its the only way i could write all the connections down and not go batshit crazy myself. soooooo many connections!!! the boards orient in different ways, so its hard to say pin 1 is pin 1, like, in the case of the fuzz and reverb board, pin one of the fuzz with the back of the board facing you would be pin 12 of the reverb. so i apologize!!

I'm pretty sure I will have some questions.  Like there's a few parts off the PCB which are point to point tack onto things.

Good stuff!!!

just let me know, i will get all the info possible!

i'm betting the whole mess could be made to run off a 9volt power supply and a charge pump!

again, thanks!

[Rob Strand]

yeah, i gotta get another circuit breaker, and i think i'll replace the filter caps, as its a bit noisy.  but maybe leaving it on for a couple days will help, a lot of times that will "dry out"
the moisture the cc resistors tend to absorb, and make the bacon frying and hiss go away.

I guess that's the problem with old stuff now.    The caps are really on the edge of the cliff.   Those cc resistors drive me crazy.   I know it's anti-mojo but when you have resistor values drifting and things getting noisy it's a real pain.

oh hell yeah... this thing feeding my echoplex outta channel two into the wet channel of my pro reverb, and the dry channel getting the main out with reverb? be still my heart!!
i am a huge fan of multiple reverbs being on. live, i tend to run one on my board, one on top of my amp as a line driver/buffer with more reverb, and the one on my amp cranked up a fair amount. reverb narcossis? naaah... but really complex reverbs and tone? oh hells yes!

Believe it or not, I've never tried that. 

belly button window comes from hendrix, belly button contemplation comes from mad magazine back in the 60's raggin
on hippies, nelvana came from the old holistic harry cartoons in playboy in the late 70's and early 80's... somehow the whole mess sloshed around the abcess twixt my ears til it came out like that.

That's a complex recipe.   I do remember the Mad magazines, perhaps more from the late 70's.

sorry, my bad. i made a conscious decision to locate pins via the keyway, its the only way i could write all the connections down and not go batshit crazy myself. soooooo many connections!!! the boards orient in different ways, so its hard to say pin 1 is pin 1, like, in the case of the fuzz and reverb board, pin one of the fuzz with the back of the board facing you would be pin 12 of the reverb. so i apologize!!

It's OK.  I tried to eyeball it and keep the number in my head but it only takes a bit of tiredness and I start losing the plot. 

The mixer is a bit weird it has eyelets but it also has a few solder tags.   I included the solder tags in the numbering.

One question,  on you wire list for the mixer, does pin 4 go to channel 1 volume (not channel 2)?

my bad. i made a conscious decision to locate pins via the keyway,

I'll try to stick to that on my schematics and renumber the lists if required.

i'm betting the whole mess could be made to run off a 9volt power supply and a charge pump!

Probably.  There's actually quite a few parts on the channel boards but not too bad.  If you dump the reverb, mixer, tremolo, and tuner  it would be vastly simplified.

[pinkjimiphoton]

i will check the wire to be sure when i go downstairs in a few, but pretty sure channel 2 only. i will confirm, also gonna write out the connections for the vegematic switches so i can reassemble her and button her up.
todays the first day i feel ok, if tired, i may run out of steam, so....



but its alive!!!! lol

i think it would make a great little standalone project. but.. the trem is kinda weak, the REVERB is incredible tho.

the caps are indeed old. i gotta haynes jazz king from 1959 thats easily 10 years older, and the filters are STILL ok in it, cuz they over-rated them so much. the haynes has a circuit breaker, too.

this thing's main cap is 10,000uf at 150, so... i wanna verify that voltage tho, i imagine its more like 200 or 250. overrated like that seem to survive better in my limited experience so far. i dunno if they develop their full potential like that, but, hey, if they work....

still, gonna probably replace just for safety's sake. if ya really crank up the amp, this thing is loud hissy and obnoxious

kinda like me

i never use CC anymore. i replace everything with metal film and be done with it. cc mojo is largely bullshit. they're spitty, crackly, hissy, muddy devices. @#$% 'em. lol

most of the caps in the circuit itself are all poly or orangedrops or similar. power supply is three can caps and two big diodes, with a transformer to step down the line voltage to about 28 volts i'm imagining. been a long time since i messed with amps so i forget how the formulas work for it, but the b+ works out to about 22 volts in the end.

i am a HUGE fan of multiple reverbs. for extra added points, throw an echo in the mix too, and you can recreate a lot of environments. of course driving a fender or marshall or whatever into distortion WITH REVERB is a completely different animal than reverberation post distortion! try it. i think you may like it.

much smokier sounding to my ears, and not as much diffusion it seems like... the guitar sound still cuts thru.

dick dale can't be wrong

i started reading mad when i was about 4, stolen from my brother. no wonder i'm all messed up.

yeah, the mixer i have a feeling was used in more than one product, from the way it appears to be wired... like, multiple wires soldered to one point, or wire stripped "in the middle", soldered to it, then run to other points.

somebody somewhere is gonna be glad we did all this someday.

watch... i'll make a freekin video extolling its virtues, and suddenly they'll pop out of the woodwork like %^&*roaches lol