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

[pinkjimiphoton]

r.g., should i measure the resistance of the pots on the bottom board? can i just measure across pins 1 & 3, or do i have to unsolder them to get the readings right? looks like there's a few components mounted on strips too that aren't shown on the schematics, i don't know enough about the disc caps to speculate on what they are, but i can probably get the codes off of them, i think they may be worth adding to the board itself tho ultimately to simplify the whole thing.

the two output jacks are mono, unswitched...the lo z input is a mono switching jack, the high z is mono, switched as well...both appear to just switch tip to ground when nothing is plugged in.

just looked at the little terminal strip, i spoke too soon...it's on the lower left side of the bottom plate, and is a .1mf 50v ceramic disk, and a resistor that's marked yellow, purple, orange and silver....1/2 watt carbon comp. sorry, still enough of a newbe where i have no idea what the value is without looking it up...47k?

on the wah pot, there's a resistor on pins 1 & 2 that reads orange orange orange...33k?

the wah pot reads (without disconnecting anything) 5.7k

the balance (actually a master volume, on the left side of the footboard) reads 9.36....10k, maybe?

the pot on the right side is measuring (lo z balance i think, the things closed up as i type this)  4.43, 5 k? pins 3 & 2 are bridged.

the wah pot looks to be a 1 watt, sealed type, the other two look like standard 1/2 watt pots.

[Govmnt_Lacky]

I think you guessed correctly for those resistor values.

If you wanna get an ACCURATE reading on those pots, you will need to remove them from the circuit. You never know what you are reading through when they are in-circuit.

[pinkjimiphoton]

i'll try to disconnect them later then and get it right. thanks bro!

[R.G.]

While I'm thinking about it - which resistors are 1W?

[pinkjimiphoton]

only one on the bottom board, on top right corner...orange white, gray, silver...cc resistor  r74 on the schematic.

[Govmnt_Lacky]

only one on the bottom board, on top right corner...orange white, gray, silver...cc resistor  r74 on the schematic.

According to schemo on Page 1

R74 = 3.9 ohms

LAMP RESISTOR

[Keppy]

height: 6 and 3/16ths inches

width: 5 inches

resistor spacing, hole to hole:  3/4ths on the 1/2 watt resistors, 7/8ths on the 1 watt resistors.

1/2 inch on the vertical trimmers.

Wow, that is some seriously wide spacing! Given those dimensions, I think a clone using modern components would have some ridiculously long leads, particularly on the capacitors. My layout's only about 3 9/16 x 2 7/8. That gives about .3' lead spacing on the resistors and about .2" x .1" on the trimpots, similar to what I've seen in many other layouts. Seems like smaller-than-original dimensions, like mine or R.G.'s, could possibly work better for a clone based on commonly available components, even without any additional modifications. Thoughts?

Maybe set the spacing for the trimmers to accomodate upright multi-turns (Bournes). They're a fav of mine. Is there any way we can combine the boards, and reduce the size of this whole deal? I'd like to see this in something slightly larger than a Morley sized pedal, if possible 

I haven't used the Bournes trimmers, but my layout should accommodate most units with flexible leads. As far as combining the boards, there's no problem producing the jpeg layout, but it would make for quite a large board. I do not believe my layout can be comfortable scaled down any more than it is (R.G. already thinks it's too small). I believe our best chance for creating a smaller unit lies in redesigning the circuit to use opamps, which would reduce the parts count considerably. Unfortunately, this is beyond my current design knowledge. If someone could come up with a schem for that, I could attempt a layout, though.

[Jazznoise]

I haven't used the Bournes trimmers, but my layout should accommodate most units with flexible leads. As far as combining the boards, there's no problem producing the jpeg layout, but it would make for quite a large board. I do not believe my layout can be comfortable scaled down any more than it is (R.G. already thinks it's too small). I believe our best chance for creating a smaller unit lies in redesigning the circuit to use opamps, which would reduce the parts count considerably. Unfortunately, this is beyond my current design knowledge. If someone could come up with a schem for that, I could attempt a layout, though.

I imagine this will be very difficult (and highly speculative since different aspects of the circuit may interact) for anyone that doesn't have this beasht infront of them. Either in a full scale clone or the original model. I may be completely wrong (And considering some of the gigantic disembodied floating brains that float around this forum I probably) but I think anything else would be speculative. Anyone really dedicated could always attempt trial and error for each element of the circuit and patchwork it.

But as I've said I'm just an enthusiastic little voyeur for this project, I'm waiting to see people like R.G and P.R.R tear this thing to bits. But considering how utterly unbusy I am at work, I may take a print out of the schematic to work and see what substitutions I can make. It's that or a laptop with CSound on it... 

[R.G.]

@Keppy:
I think that you probably want to scale yours up to a lead spacing of at least 0.4" for 1/4W resistors. You can get 1/4W resistors on 0.3" spacing, but it's not good for the leads to bend them that tightly. 1/4W really needs 0.4 or more. 1/2W resistors really need 0.5" spacing minimum. I also did not even consider axial lead caps, but went for radials, 1/4W resistors, and TO-92 transistors to start with.

I multiplied your board size by 4/3 (ratio of 0.4" to 0.3") and I come up with just a bit larger than my layout. They converge. I got the fall plate and console board combined into 4.2" x 5.5". A proto run on that size gives a per-set price of about $20 each.

@digi2t:
I didn't want to try out replicating the whole thing, since I think that most people will want the formant filters but not the fuzz, preferring to sub in their own distortion. I did redesign from concept for two OTA based state variable filters swept from opamp waveshapers on a control pot voltage, then dinked with it until the filter range and motion gave frequencies always inside the formant map. I ordered proto PCBs from this. I'll see how that works out. This was really the push I needed to go ahead and complete the "voice wah" thing from geofex after having to put it aside years ago.

[pinkjimiphoton]

rg...the FUZZ IS AN INTEGRAL PART OF THE VOICING OF THE EFFECT, imho...it's a unique sounding fuzz, and part of what gives the formants their grit and consonances.
a separate fuzz is fine. can be run into the effect, or after it...but to take it out of the equation may result in less than desirable response.

some say it's "weak", but it's not really...it's hyper distorted and compressed, and very hi-fi sounding, for lack of a better description. it basically sounds so bad, it's good.

my humble advice as a newbe is to breadboard it first with, as i believe it gives the unit a lot of it's "character".

i have a feeling dino will agree with that.

gotta go...the sheet metal bottom panel i ordered is ready to get picked up...i'll explain later...good story!

[R.G.]

Yep. I could'a messed up. That's what prototypes are for.  

Meanwhile, back at the literal clone, here's what I came up with:
http://geofex.com/FX_images/Ludwig Clone parts placement.pdf

[pinkjimiphoton]

heh heh...just got back...i have to measure it for the mounting screws and round off the top corners a little, but it fits just about perfectly.

cost me 10 bux.

ok, the story...

i was driving down the road the other day, noticed a sheet metal place...so i stop there, and walk in. the old-timer working there was a guy named frank, he told me he was 72, and used to own the place, but sold it to the new owner 11 years ago. he said even tho he could collect social security, he preferred to work.
nice guy.

i ask him how much to cut a trapezoid piece for the bottom, and give him the dimensions. he says, "well, if it were up to me, i'd just cut it for you out of a piece of scrap, but the c***sucker that owns the place now is gonna screw ya, he'll charge ya 40 bucks for a half hour". sure enough, seconds later he goes..."see that? here comes that c***sucker now". the guy walks in, so i ask how much to make the piece i need. he looks at me without a blink and says "gonna cost ya a half hour, that's fourty FIVE dollars.". i said...like...
ouuuuch!!! i said how much for a piece of scrap big enough to make it out of, and i'll cut it myself?

he says..."10 bux". i say...do ya take plastic? he goes yep, so i follow him up the hill to the plumbing joint up the hill. i pay him, go back down to see frank.

frank goes " i told ya that c***sucker would charge ya 45$!...i'll tell ya what...i'll cut it for you on my own time, and drop it off tomorrow morning on my way to a job".

so i go what do i owe you for YOUR time? "oh, buy me a cup of coffee."

so i'm typing my last post, and the phone rings...it's frank.

"hey, i'm down the street, i got your piece, i was on my way to a job and figured i'd stop and get a donut". so i hop in the car, go down there, and before i even get out of the car, he walks over hands me the piece, and says "screw that c***sucker's 45 dollars."

i go...can i buy you a cup of coffee or something? he's like, naaaah, next time, i gotta go.

how cool is that? lol!!

[Keppy]

@Keppy:
I think that you probably want to scale yours up to a lead spacing of at least 0.4" for 1/4W resistors. You can get 1/4W resistors on 0.3" spacing, but it's not good for the leads to bend them that tightly. 1/4W really needs 0.4 or more. 1/2W resistors really need 0.5" spacing minimum. I also did not even consider axial lead caps, but went for radials, 1/4W resistors, and TO-92 transistors to start with.

Thanks for the tip on the 1/2W resistors. I've never used them before, and failed to account for them. I'll scale up the boards if anyone is interested. I'm still not sure if people would rather have that size or original. Well, except for Dino, who (like me) wants it even smaller.  

I took the use of radial caps for granted as well, which is one of the reasons I made the layout small. Scaling up adds to the already large lead spacing for those parts. Oh well.

Care to educate us on your choice of transistors?

[boogietone]

I'm tellin' ya. Somebody needs to call the networks and make a reality show out of this. 

[pinkjimiphoton]

it's all good, R.G....lol.

it may be better, beats me...the only sure thing is it'll be different!!!

[R.G.]

Care to educate us on your choice of transistors?

I didn't choose them.

What I did was to note that there are only two major versions of pinout for small signal transistors - EBC and ECB. The original was EBC, and I have a big stock of those, so I just made all of them TO-92 with base in the middle.

I *think* the actual transistor should not matter a lot, but there may be some need for matching Hfe or Vbe for the "differential" pairs in the two filters. Don't know yet.

For those of you who have the actual units, it would be interesting to see the printing from the transistors, whatever it is. These were made during a time of rampant "house number" mania, so they may have only numbers like "2384732" that don't translate to commercial types.

The actual transistors from that era varied even more than modern ones do, so it may be that they were hand selected.

[pinkjimiphoton]

the board says EV on it...electro voice, methinks, which would make sense, seeing that ludwig was never really an electronics entity.

not sure of the trannys, but i suspect r.g. may be right, the tops of the trannys are color coded.

i'll try and find a magnifying glass and see if i can make out any of the numbers on them tomorrow if i get a chance.

r.g., i'm confused...is ebc npn and ecb pnp or something? remember, i'm a newbe so i'm a little confused. i do remember running into that with a 2n5088 sub from nte on one of the projects i built...i didn't look at the pinout (beat me now) and couldn't figure out why it didn't work until i noticed that.

anyways...we'll no doubt figure it out soon enough i guess. i'll do my best to try and read the numbers on the trannys, but i have glaucoma so seeing little things can get really dodgy with me. especially now that i no longer ....ummm...."imbibe" in the "cure".

onwards and upwards!!

[pinkjimiphoton]

looks like mike mathews is watching this thread or something...

honestly, may be cheaper for some to just buy this thing...but nowhere near the mojo factor!!

looks like another candidate for clonage...lol

the first setting is close enough to piss me off,,, lol

[R.G.]

i'll try and find a magnifying glass and see if i can make out any of the numbers on them tomorrow if i get a chance.

Thanks!

r.g., i'm confused...is ebc npn and ecb pnp or something?

The letters stand for Emitter, Base and Collector. In the TO-92 plastic package, with the pins down and looking at the flat face, the pins are numbered left to right 1-2-3. "EBC" pinout means 1 = emitter, 2 = base, 3 = collector. "ECB" pinout means 1= emitter, 2 = collector, 3 = base. USA "2N" transistors are much more commonly EBC. Japanese "2Sxxxx" and some European BCxxx devices are ECB. Some Euro devices are also CBE, just backwards from "2N". The 2N5088 and 2N3904 are EBC. This has nothing to do with NPN or PNP. Either NPN or PNP can have either pinout.

i'll do my best to try and read the numbers on the trannys, but i have glaucoma so seeing little things can get really dodgy with me.

Sorry to hear that. I started having to have visual help some years back. I highly recommend the magnifying visor from Harbor Freight. They're commonly as little as $5-$7 on sale. I buy a couple every time they are on sale and stash one every place I might need one.

The world is slowly filling up with them... 

[Keppy]

For those of you who have the actual units, it would be interesting to see the printing from the transistors, whatever it is. These were made during a time of rampant "house number" mania, so they may have only numbers like "2384732" that don't translate to commercial types.

Did you see the cross-reference links I posted earlier in the thread for the transistor numbers in the schematic? They seemed plausible to me, but I know nothing about transistors from back then (and little about the ones they make now).