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

[digi2t]

I'm really curious to see if the clone has the same fuzz volume drop when the formants are off. That's my biggest pet peeve about this box, kill the formants, and you really lose the fuzz. I can understand that by changing the resistor on the negative rail in a fuzz face, will boost or cut the volume. I wish there was a similar solution here, but I don't have the technical expertise to figure it out. I've been looking at the schematic, in the hopes that something familar jumps out at me, but to no avail.

[pinkjimiphoton]

well, if ya lift the ground on that 150r resistor on the fall board, like when mine broke, and adjust the two top trimmers on the fall board, you can get the fuzz screamin'. but then ya lose the formants completely, and it won't work quite right when ya reconnect the pot.

i think it's just one of them compromises we gotta live with bro.

[Keppy]

well, if ya lift the ground on that 150r resistor on the fall board, like when mine broke, and adjust the two top trimmers on the fall board, you can get the fuzz screamin'. but then ya lose the formants completely, and it won't work quite right when ya reconnect the pot.

i think it's just one of them compromises we gotta live with bro.

How important are the trimmers? Seems like it would be easy to run the ground of that resistor to the switches so that it would be lifted when they're all off. Just get switches with an extra pole, and attach the now-grounded end of the resistor to the "on" position of all three switches with the center lugs connected to ground. Turning on any of the formants would then connect the resistor to ground, but having them all off would lift it.

[Keppy]

I finished the wiring and fired the thing up, and it works! 


...


...but only in bypass mode. 

What I have now is essentially a functional 1970s style buffer with lots of pretty lights. Guess I'll start debugging tomorrow.

On the plus side, the fact that the buffered signal is clean and not noticeably noisy makes me optimistic that the 48v switching power supply I hooked into the onboard regulator will work well. Stay tuned...

[pinkjimiphoton]

if all you're getting is the buffer. check the trimmers...start with all about half way up. it sounds like it's close, if it's passing signal.
i guess now is the time to start asking for voltage readings at specific points maybe?

i got faith in ya keppy!!

[Keppy]

I set all the trimmers as described before I fired it up. They're all at halfway, except for the 100R which I set at about 3/4 (roughly, no measurements). Though, now that I think about it, I might have missed the two on the console board. I'll check when I get home.

My own suspicion is that a transistor is either loose in its socket or physically wrecked due to cramming it into a socket. I plan to check them all just to make sure they're operating. If they are, I'll compare the readings more carefully to those posted earlier from the originals. Like you, I'm pretty sure that since the bypass buffer works I probably haven't screwed anything up TOO badly. No power/ground faults, for example. As to the rest, we'll see.

[R.G.]

When you get the chance, it might be useful to go ahead and take the pin voltages on all the transistors.

Yep - it's a PITA, but it's deadly effective on many firing-up flaws.

[digi2t]

Seems like it would be easy to run the ground of that resistor to the switches so that it would be lifted when they're all off. Just get switches with an extra pole, and attach the now-grounded end of the resistor to the "on" position of all three switches with the center lugs connected to ground. Turning on any of the formants would then connect the resistor to ground, but having them all off would lift it.

That would definately be an avenue to explore. You'll see Kep, the fuzz is really anemic on it's own. It would be really cool if a mod was possible to bring the fuzz to unity (or close). It's a wicked, nasty fuzz, that's begging to be heard. You may want to try recreating Jimi's situation, once you've got your debugging done.

Just out of curiousity, did you incorporate that "Rangemastery" looking, offboard terminal strip circuit into the clone?

[Keppy]

You may want to try recreating Jimi's situation, once you've got your debugging done.

Maybe. it would be a gigantic pain to replace those switches (as I suggested) after the fact. I might be able to lift the ground on that resistor, though, just to experiment. We'll see. Perhaps an extremely high value resistor on a switch would accomplish the same thing as lifting the ground.

Just out of curiousity, did you incorporate that "Rangemastery" looking, offboard terminal strip circuit into the clone?

R.G. included that on the board at my request, as I didn't want to have to deal with it later or make an extra board. I'm halfway through checking the transistors, and already replaced that one, incidentally.

[Keppy]

I've zeroed in on the problem, if not the solution. It's the transistor in that add-on amplifier. If I connect an audio probe to the base, I get signal. To the collector or the emitter, nada. Voltage reads full supply on the collector, nothing on the base or emitter. I am currently using a 2N5551 in that spot.

Earlier posts mentioned an undocumented resistor (1Meg, I think) that R.G. speculated might be used to bias that transistor. What can you guys tell me about that? I'll see if I can find the post...

[Keppy]

Here's the post.

From the last round of circuit info, I found that the terminal strip circuit is an amplifier between what would be the output and the "bypass balance" pot. It amplifies the audio output. However, it's a very odd amplifier. The base of that transistor goes to pin 6 on the fall plate, no biasing components, and on the schemos that point is DC-blocked. I wonder if the added 1M resistor that I see on the pics of the fall plate board are to provide some trickle of bias to this.

[Keppy]

Tried applying 9v DC from a separate adapter straight to the base to bias it. No luck.

[digi2t]

Are you talking about this?;



If so, it consists of 47k and 10k resistors, 0.1uF cap, and a 2N4401 tranny. Maybe the 2N5551 isn't cutting the mustard?

I was looking at the schem again, and I'd like to run something by you guys, insofar as the volume output of the unit is concerned. On the fall plate diagram, point 6 (to my untrained eye) seems to be the output of the unit. It goes through the terminal strip/amplifer section, and then out. Resistor R73 sits between point 6, and ground. Wouldn't this resistor directly affect the output level of the unit? If so, could we switch between two different resistances, via the formant switches to A) Bring the volumes to unity, and maybe B) Make the unit a bit louder overall? Or maybe a balance pot arrangement, allowing the user to vary the balance between fuzz, and fuzz/formant output. 

I hate to keep harping on this, but it really is a major weak point of the unit. If I could catagorize the volume output level of the unit, in it's various operating modes, it would be as follows (except for bypass, which is adjustable);
Fuzz - weak
Fuzz + Formants - louder
Formants (no Fuzz) - loudest

And, as a sidebar, I've found that vowel pronunciation can vary on the unit depending on the input signal volume as well. At certain points, with the guitar on full volume, in formant "C"/no fuzz mode the unit will produce bow wow wow, but roll off the guitar volume a bit, and it cleans up to yoy yoy yoy. Almost as if the guitar alone were overdriving the unit. Not something I would necessarily want to correct, but I thought I would put it out there as FYI. I find that it does allow some tonal pallate change on the fly, without having to touch the unit. I'm using a cheap Strat copy with it right now, and I don't think the pups are THAT hot, but I imagine my Motherbuckers loaded Ibanez will probably do a wicked job on this sucker. Maybe an input level pot wouldn't be a bad idea?

Jimi, if you've got the time, could you confirm my statements bro? Thanks!

[digi2t]

Hey guys, guess what... I just scored a second unit!

This one needs to be repaired. Apparently, it's got no animation, and the footpedal is offline as well. Fuzz and formants are fine. Most probably bad solder, wire connection to the board, or broken solder joint. I'm going to take all the necessary measurements off this one as well, that will give us a better idea (if it hasn't been tampered with) insofar as setup is concerned.

Then... I'm flipping one to help pay for the Goldwing. Oooorrrrrrr, keep it and run them both in stereo.

Sh*t... I'm gonna need a third leg. I'd better start scouring EBay......

[nocentelli]

keep it and run them both in stereo.

Haha, I can just imagine the conversation - "My rig? Oh, nothing much in the way of pedals, I've just got two Ludwig Phase II's that I run in stereo..." 

[Mr Bill]

Hello, everybody - I came across Jimi's PII demo on youtube on a whim search.  I've owned a PII since 1973, but it went into disrepair when a couple of the wires came loose on the top deck & needless to say with the crummy documentation, wasn't able to resurrect it. I've been waiting 37 years for info to reawaken the beast and after contacting Jimi via facebook, he turned me on to this forum!  I just power-read the entire thread and am going to reanimate the box. What an incredible labor of love!  I wish I had found this back in May, as I could've supplied pictures, etc. Anyhow, looking forward to resurrecting mine and sharing on this forum! Pls I don't to bother Jimi on facebook, when this is clearly the place to discuss this project!

Mr Bill  (Bill Soule)   

[Mr Bill]

Whoops!  I meant to say  "Plus I don't want to bother Jimi on facebook...." 

[pinkjimiphoton]

ooooooooooooooooh nooooooooooooooooooooooooo, mister billllllllllllllllllllll!!!

dude, it is no bother whatsoever!! hit me up anytime, my friend.

i wanna see/hear pics and clips asap!!

and if ya get stuck...wellp, you've come to the right place bro.

plus...seeing as how you have a unit as well...it  may be good to compare notes about some of the diffs between the units!!

also, would absolutely love to hear about the gain mod you were working on when it broke back in '73.

talk soon bro..peace!

[digi2t]

Welcome to the forum Bill. My name is Dino, Jimi's my homey, and fellow Ludwig afficianado. I currently own two units, and Jimi and I have been the go betweens for Keppy and R.G. for this clone project. You can find all the documentation compiled to date here; http://www.geofex.com/Article_Folders/Ludwig_P2/Ludwig%20Phase%20II%20Tech.pdf, and the interconnection diagram here; http://www.geofex.com/Article_Folders/Ludwig_P2/Ludwig_Clone_PCB.pdf .

There is another thread, http://www.diystompboxes.com/smfforum/index.php?topic=92125.0 , these are all the tech notes compiled for the clone build. You'll find a boatload of details here, including trimmer settings that Jimi and I are using insofar as unit setup is concerned, observations, opinions, and other relevent information. Thanks to R.G. for starting that one, keeping the hype to a minimum, and concentrating on the important stuff.

Welcome, and cheers,
Dino

[Mr Bill]

Thanks for the welcome, guys -

The gain circuit I was talking about inserting to make up for the Hi Z lack of gain was actually to clone the off board kluge gain (treble circuit) that's on that infamous terminal block. I was in 10th grade when I was postulating this and it occurred to me that this circuit must have been a bandaid circuit after the main boards had been released (probably to quench the propensity of the unit to break into wild oscillation as Jimi had stated) and I figured I would just clone it and break the input and cascade it in.  I never ended up doing it, but when getting back into this unit after 37 years, I didn't know if I had put that terminal block there or if I had added the transistor myself. Thanks to this forum I now know that this was all original and that I only "planned" to clone this and insert as another gain stage. This was yet another reason why I thought I had hopelessly sabotaged restoring the unit. There is a transistor that I had cut out of circuit on the lower board to measure it's forward/reverse resistance (modern DVM can do this so much easier with actual junction voltage drops) and I remember when lifting out the upper deck in 1974 I shorted the +35V rail to ground and wiped out the series-pass transistor on the power supply. I replaced it and the power was restored.  I very vaguely remember that a couple of the circuits/paths may not have been working, but that may have been lack of knowing the natural signal paths/functions at that time.  The schematic deficiencies just kind of squelched in my mind any chance to resurrect the beast.  BOY, WAS I SO WRONG!  We will have a trinity soon....Frankenstein, circa 1931..IT'S ALIVE!!!..