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

Started by pinkjimiphoton, May 08, 2011, 12:11:42 PM

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R.G.

On the power supply, I've been thinking about that. For a clone, a DC-output wall plug would be a whole lot better. Not knowing how much current it eats until/unless it gets measured on a real or clone, it's hard to design a charge pump to work right. If the current's high, it may be hard to get a charge pump to get to 35V.

I like the idea of running it from a 24Vdc nominal output wall wart. These are cheap and easy to find, and usually have an output that is larger than the stated. I just bought a couple for another project. They put out 31.1V unloaded. The other option is to use a 15-18V AC output wall wart and use diodes and caps to double it to over 35V. Lots of options, not much real information. Mouser stocks 48Vdc output wall warts. That should be OK for the raw power. There's a regulator on the PCB anyway. Just have to make sure it doesn't burn out with 48Vdc in.

I did run the filters in the simulator and they do work at 24Vdc, but whether it all works and sounds right is not something a simulator says.

A couple of other questions remain. It's not clear what kind/type of switches these things use. For instance, the animation speed switch. Is that an SPDT, with the pole to +35? The schemos do not say, and all I can figure out from the pictures is that it probably does that. Stuff like that.

There's plenty to chew on from the wire tracing! Thanks.
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

pinkjimiphoton

the animation speed switch determines how fast the animation begins it's modulation...in slow position, it ramps up slowly, relative to the max speed set by the slide pot.
in fast position, it goes right TO  the preset speed. the coolest part is that when ya use the footswitch to turn off the animation, it ramps back down to just wah pedal control.

that switch is dpdt i believe, on/on.  it's hard to tell cuz of the archaic switches, they look like the switches for the pickups in old gibsons.

the select switch is a dpdt on/on/on i believe. it chooses ffm (formant filter modulation)/both/fuzz repeat.

formant trajectories are all dpdt on/off switches

the fuzz/voice fuzz is the same too i believe. while dino's got his apart, maybe he can check. my eyes are all bugged out still from all the stuff yesterday and kinda fuzzy.

but i don't think they are anything other than normal kinda illuminated "wafer" switches...the plastic parts are clear,and have little gels inserted so they can change colour.

and, fwiw, the highest voltage i read to ground anywhere was 19.8v...so i'm assuming that means about a 35 volt supply, peak to peak?
am i in the ballpark?

i know it's a 35 volt supply, but i mean, is that why i read about 19 volts?

thanks guys...


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pinkjimiphoton

ARRRRRRRRRRRRRGH!!!! F***!!!

just plugged it in, cranked it up. it SOUNDS killer.

but the hum is still there, and in spades. happens most when the fuzz and animation are turned off, of all things. crazy.

tried turning the wall plug over...slight reduction, hum still there.

tried kicking it. (seriously)...no change, tho stomping on the floorboard DID make it stop...but then it started again.

i know all the electrolytics are good...

so...i'm thinking, where is noisy ac 60 cycle hum gonna come from other than the caps?

diodes?

could i have inadvertantly wired the grain of wheat lamps backwards?

lead dress maybe (one of the wires to the floorboard lamps passes over the dry output balance pot)?

or...gulp...transformer?

or...could it be that the bottom plate isn't being grounded to the chassis cuz i forgot to cut the vinyl covering under the screws to make a good earth connection?

any ideas?

hellllllllllllllllllllllllllp!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

it sounds KILLER  thru a clean amp if ya gotta noise gate cranked...but the part that's throwing me, is why the hell would the hum go away when ya kick ON the fuzz????

shouldn't it be the other way around?

i expect some hum from a vintage device, but this is crazy. so...i'm thinking diodes. if the caps are good, and a diode fails, that can make it hum, right? i did notice some of the diodes looked like glass kinda germanium types, and they leak like a sieve some times...

gotta go out, will check back when i get home. frustrated!!!!!!
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newfish

Jimi, R.G., Dino...

This thread is my television, and I thank you all for it.

What you're doing is DIY FX at its very core.

I may never build one, or even try to find one to use on a recording, but your enthusiasm is immense.

I wish you every success in your reverse-engineering, clone project.

I'm thrilled to be reading this thread as it unfolds.

Cheers Guys!  Best of Luck!

Ian.
Happiness is a warm etchant bath.

R.G.

Here's all I know about the wiring so far. Circles with question marks in them are where I know that I don't know what's happening. There are probably places where I don't know things that I don't know.
http://www.geofex.com/FX_images/Ludwig%20interboard%20wiring.pdf

As to the hum. Hum comes from many places, not just power supply ripple. If you listen carefully, you may be able to tell the one-octave difference between true AC power line ripple, which is 60Hz, and power supply ripple, which is 120Hz and "fuzzier". Sometimes not.

I suspect that you have a ground wire loose, or that the AC going to those (worthless...) incandescent lamps is inducing hum by passing by some signal wire in an unfortunate way.  A loose jack bushing nut can do it, as can a loose wire grounding (well, OK, not grounding) to the chassis well.  Don't get too upset about hum at the moment.
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

pinkjimiphoton

thanks newfish.

sumbitch. the brand new c1 on the fall board is bad, if ya touch the case, it sounds like touching the end of a guitar cord. gonna cut one of the leads and bypass it with a 100v 22mfd, see if that cures it.

that helped some, but it still has a hum to it. i messed with the trimmers some, discovered you can get some positively WACK sounds out of it when it's set to self oscilate.

i messed with the lead dress, and removed one wire at a time from the fall board...seems the "treble booster" thing seems to have an effect on the hum.

also discovered it seems acceptable into a clean amp...but FORGET running it into a distorted amp. hum city.

weird...hopefully will figure out the rest of the issues.
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pinkjimiphoton

ok, r.g.

i too suspect lead dress...that's why we twist the ac line to the heaters in tubes, to reduce the hum some. i'm wondering if maybe i can "float " the ac like in the heaters of a tube amp? it's definitely better now...c1 was a bad cap. doubling the voltage and the capacitance definitely helped a bit.

i'm wondering more and more about just replacing them grain of wheat lamps with led's. especially if it'll nuke some of the noise.
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"When the power of love overcomes the love of power the world will know peace."
Slava Ukraini!
"try whacking the bejesus outta it and see if it works again"....
~Jack Darr

R.G.

Quote from: pinkjimiphoton on June 05, 2011, 04:56:17 PM
sumbitch. the brand new c1 on the fall board is bad, if ya touch the case, it sounds like touching the end of a guitar cord. gonna cut one of the leads and bypass it with a 100v 22mfd, see if that cures it.
Doesn't happen often, but it does happen. It's pretty clear that the internal lead was open. When you touch the cap, it *is* just like touching the end of a guitar cord, and for the same reason. Increasing the capacitance and/or voltage don't help or hurt, it's just that the new cap is actually connected inside.

Quotei messed with the lead dress, and removed one wire at a time from the fall board...seems the "treble booster" thing seems to have an effect on the hum.
also discovered it seems acceptable into a clean amp...but FORGET running it into a distorted amp. hum city.
I suspect the grounding scheme inside is not the best. A dirty amp will amplify any low signals more than the guitar signal, because the guitar signal is limited by clipping, the hum is not. So the hum gets proportionately louder. Hiss, too.

Quote from: pinkjimiphoton on June 05, 2011, 04:59:55 PM
i too suspect lead dress...that's why we twist the ac line to the heaters in tubes, to reduce the hum some. i'm wondering if maybe i can "float " the ac like in the heaters of a tube amp? it's definitely better now...c1 was a bad cap. doubling the voltage and the capacitance definitely helped a bit.
i'm wondering more and more about just replacing them grain of wheat lamps with led's. especially if it'll nuke some of the noise.
I think that getting AC out of the wires would help more, whether the lights are incandescent or LED. I am not sure about what goes to what for the lamps to work, but I think they may be running on the pure transformer AC. If they are, then just switching them to DC will clean up the AC induction.

Getting the high voltage AC out of that harness to the top/console board will help too.
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

pinkjimiphoton

something's up...the pedal is DEAD. the cap i replaced it with is now doing the same thing, so something is majorly wrong. i had it working great, tried setting the trimmers as suggested by dino...was working, but seemed to need a little tweaking. was tweaking one of the trimmers, and poof...the whole thing crapped out, was barely passing signal at all.

i've played with it for the last hour or so, can get the fuzz to work, but the wah part is dead. some of the trimmers are now acting like volume for the fuzz, getting no modulation at all, tho the repeat percussion thing is indeed working, so something is wonky as hell.

i am stumped completely. gotta go to rehearsal, i'm already gonna get there 1/2 an hour late.

man, i could scream/cry right now. this thing is way beyond my limited abilities to figure out.

f**k me!!!

don't even know where to start ...if i snap the wah pedal hard toe down, it kinda kicks on a little bit, but then again, only fuzz.

just tried cleaning the trimmers...wondering if they broke down internally or something.

but that cap blowing out has me spooked, as it was a 100 volt cap!!

it shouldn't have blown, was working perfectly until whatever the hell happened.

more later...this sucks!
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~Jack Darr

R.G.

Quote from: pinkjimiphoton on June 05, 2011, 06:47:37 PM
something's up...the pedal is DEAD. the cap i replaced it with is now doing the same thing, so something is majorly wrong. i had it working great, tried setting the trimmers ...
it shouldn't have blown, was working perfectly until whatever the hell happened.
Take a deep breath. You've already faced the worst thing with the unit - you can't get an identical replacement pot for the front panel. Everything else is fixable, with some degree of effort.

This is a common type of failure for elderly effects. They kinda work, then they break down.
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

digi2t

Jimi, dude, bro,

Like R.G. said, take a step back, deep breath, and just scan it slowly. I've already had to repair two wire breaks, right at the solder. Both on the upper board. These babies are so brittle, that just looking at them hard can shake shit loose. The upper board is especially suseptible to breaks because of the gymnastics needed to get it out of it's place. The wiring HATES it. First time around I lost the fuzz, and then the lamps feeder. Easy fixes both times, but real heart stoppers. 1200 reasons to stop my heart. But, I believe that component-wise, these suckers should be like Mack trucks. It's just the nuts and bolts like wiring or solder that's weak. I'm putting my money on a wire or solder being the problem.

One of the things that really bugs me about this unit, is the 2 prong plug. I'm no expert, but unless I see an inset double square on a piece of kit, 2 prongs on a plug make me nervous.

Jimi, was the hum happenning when you plugged into the Hi Z, or Lo Z? So far, with my shitbox amp and Crapocaster, one side or the other sounds the same to me, and the Lo Z balance pot doesn't seem to do anything to my ears. As a matter of fact, the connection points are mislabeled on the motherboard diagram. Connection points #2 and #3 are both labeled as Low Z In, when in fact Hi Z is #2, and Lo Z is #3. Plugging into Lo Z, and playing with the balance pot, I don't here any difference in the signal. UNLESS... having looked at the hardware again, it's only active if you plug 2 signals in. Then you could balance between the Hi and the Lo signals. After all, if there is no cable plugged in to a particular input, that input is grounded.

Strange days indeed my friends...... 
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pinkjimiphoton

trying to breath. not easy. dicked around with it last nite for a little while, kinda got the mod to work a little.

replaced that cap again, brand new cap, same problem. wondering if it's installed backwards...but seems right, stripe is negative.

may try again today. i think trimmer r29 is broken down, i can't seem to read any resistance across it.
also notice something is up on the right side of the board...at one point i hit something and it came back, but i couldn't reproduce it again.

it's gotta be something stupid, but this thing is indeed overwhelming me. about ready to send it to R.G. with my credit card to see if he can figure it out, lol..
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"When the power of love overcomes the love of power the world will know peace."
Slava Ukraini!
"try whacking the bejesus outta it and see if it works again"....
~Jack Darr

artifus

hang on in there bro! which cap? i'll have to recap (excuse the pun) on the schem but it's gotta be just before or after, right? could you temp a fixed resistor across r29 for testing? and if tapping the board is having some effect maybe a dry joint? bit of a reflow maybe? just thinking out loud, not been following as closely as i should and wanting to keep your spirits up.

thedefog

Quote from: artifus on June 06, 2011, 10:44:24 AM
hang on in there bro! which cap? i'll have to recap (excuse the pun) on the schem but it's gotta be just before or after, right? could you temp a fixed resistor across r29 for testing? and if tapping the board is having some effect maybe a dry joint? bit of a reflow maybe? just thinking out loud, not been following as closely as i should and wanting to keep your spirits up.

Good point. Whenever I get a hold of old gear to repair the first thing I do is reflow solder everywhere. It's pretty much a given for anything 20+ years or older. And I'd say 50% of the time it is all that is wrong with the stuff I get. You'll get it working again Jimi.

Govmnt_Lacky

Just wanted to chime in and say:

"Sixteen pages in less than a month.... HOT TOPIC!"  :icon_eek:

Keeping an eye on this one. Looks promising  :icon_wink:
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for an amount of 'up to and including my life.'

digi2t

Quote from: artifus on June 06, 2011, 10:44:24 AM
hang on in there bro! which cap? i'll have to recap (excuse the pun) on the schem but it's gotta be just before or after, right? could you temp a fixed resistor across r29 for testing? and if tapping the board is having some effect maybe a dry joint? bit of a reflow maybe? just thinking out loud, not been following as closely as i should and wanting to keep your spirits up.

This is so true. I've got an old Gibson 2x12 combo amp that started to crakle a while back, whenever I would play loud and clean through it. It would never do it when using distortion. I found that it was cracked solder joints. The board would just vibrate harder clean than dirty, hence the crackling. I reflowed all the soldering, and presto!, crackle gone.

I know this will be a bitch because it's a pain to pull the motherboard out far enough because of the wiring. I know this for a fact, from when I photographed the trace side, but here goes; Check the diagram, the trimmer resistances are marked. I don't have the diagram in front of me, but (for example) if it's a 10K, take an ordinary pot, put some leads on it, pull out the trimmer, and solder in the leads of the pot in it's place. Bridge the wiper of the temp pot to one of the outer legs, and by looking at the traces, you'll see which lead will solder to the bridged side, and the other solo.

Quote from: pinkjimiphoton on June 06, 2011, 10:23:48 AM
it's gotta be something stupid, but this thing is indeed overwhelming me. about ready to send it to R.G. with my credit card to see if he can figure it out, lol..
Besides that, I'm sure that R.G. would be just trilled to eye-ball one of these suckers in the flesh!

"Give me 500 cc's of adrenaline, and...... CLEAR!"  ;D
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pinkjimiphoton

lol...thanks for the support guys. means more than you know. :icon_mrgreen:
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Slava Ukraini!
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~Jack Darr

digi2t

Quote from: Govmnt_Lacky on June 06, 2011, 11:56:53 AM
Just wanted to chime in and say:

"Sixteen pages in less than a month.... HOT TOPIC!"  :icon_eek:

Keeping an eye on this one. Looks promising  :icon_wink:

Lacky,

I tell you, I've got a SHITLOAD of effects. Rack effect, floor effect, pedals, processors, you name it. There probably isn't a tone on the planet a couldn't cop, and probably a bunch in there that don't exist... yet. My pedal board is double tiered, 6' long by 2' wide, and packed. That's all connected my 14 space rack, and that's packed.

BUT....

Playing through this thing, into a clean amp, is just nirvana. I've never experienced anything like it. It's nasty, and sweet. Confusing, yet soothing. It's like that bitch of a girlfriend that makes your life absolute HELL, but you just can't leave her behind you because the sex is sooo damn good.
Yes, I did spend the 1200$ because I felt like treating myself, but now it's become my personal mission in life to help in any way possible to clone this this.

So let it be written... so let it be done.
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R.G.

Just as a safety net under you, *everything* on there can be replaced, remember.

And I just wrapped up the final (I think) version of the fall plate board. It's 3" x 4".  :icon_biggrin:

At some point you'll be able to put in a NEW fall plate board, and console board. 
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

digi2t

Quote from: R.G. on June 06, 2011, 12:47:33 PM
Just as a safety net under you, *everything* on there can be replaced, remember.

And I just wrapped up the final (I think) version of the fall plate board. It's 3" x 4".  :icon_biggrin:

At some point you'll be able to put in a NEW fall plate board, and console board. 

Hey R.G.,
3 x 4  :icon_eek: :icon_eek: :icon_eek: my god man! That will be amazing!!

I printed your wiring layout yesterday, and I'm going to sit down and fill in the blanks for you tonight. I'm going to do it by hand, scan it, and then post it back up here. I'll try to be neat as I can. Since I moved last week, all my usual resources are in boxes, but I do have access to a scanner and my girlfriends P.C.. I'll try and make some honey outta this dogshit for ya!

Cheers,
Dino
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