Ludwig Phase II Clone Debugging and Miscellany

[digi2t]

I have checked the voltages of those transistors and according to the build document they seem right. The only thing that I have noticed is that when I put the switch on fast start, the emitter voltage of Q1 start to drop toward 0V. But I guess it is normal.

Yeah, that's fine. This transistor is part of the fast/slow scheme.

Just make sure that the unused Lo-Z input is grounded as well when you go back to your troubleshooting.

And Dino, where did you get your pot for the expression pedal? I'm having a hard time finding one with enough threading to be able to secure it properly in the shell.

Those pots are made by P.E.C.. I use the long shaft version, which I cut down to size. I also use the flat shaft style pinion gear, with the circlip. I make the groove for the circlip with a Dremel.
Digikey has them, here is the web catalog link; http://www.digikey.com/product-detail/en/RV4NAYSJ103A/RV4NJ103C-ND/222783
Another suitable workalike is the Clarostat model, pricier, but available at Newark, Digikey, and Mouser. The nut MIGHT come seperately on this one, so heads up. The part number is 380C110K. I've never used this model, but from the drawings, it looks like a P.E.C. clone.
You can get the P.E.C. pots at ABRA Electronics too, at around 9$ each. But, there is a minimum order charge with them. I'm lucky, ABRA is only about 40 miniutes away from me, so when I don't have enough to make up a mail order, I'll just drive down to the store.

I've found that for weird value wah pots, these work great. They fit the Dunlop shell perfectly as well.

[Vince_b]

Just make sure that the unused Lo-Z input is grounded as well when you go back to your troubleshooting.

I 've used switching jacks for tthe intputs so that's ok.

I have started to use an audio probe in hope that it will help me to find out where is the cause of the problem. Just to be sure that I'm understanding the circuit properly, if the signal coming out of the fuzz footswitch is good, am I right in assuming that the problem cannot be in the "inputs, mixer" nor in the "fuzz/non-fuzz signal  to filters" sections?

[digi2t]

Just to be sure that I'm understanding the circuit properly, if the signal coming out of the fuzz footswitch is good, am I right in assuming that the problem cannot be in the "inputs, mixer" nor in the "fuzz/non-fuzz signal  to filters" sections?

The fuzz on/off footswitch is a good place to start. The center (COM) pole feeds the filters, with one side bringing in the clean signal, and the other the fuzz signal. So, if your fuzz and clean signals are good and strong, then it must be further down stream.

Check the QF+1, and the associated resistors/caps/voltages as well. This is an output amplifier that is fed from the two filters, so it might be here as well.

[Vince_b]

Check the QF+1, and the associated resistors/caps/voltages as well. This is an output amplifier that is fed from the two filters, so it might be here as well.

DINO YOU'RE THE MAN!!
You just made me realize how stupid I can be sometimes... For some reasons, I thought that QF+1 was an optional part, something to use only for some kind of mod to get it closer to the orignal. I really don't know where I got this from.
So, I've just soldered a tranny in there and that WORKS!!
Although it is a really stupid mistake, I'm kinda glad that it didn't work at first. My little troubleshooting odyssey made me take the time to understand the basics of how this circuit works. Otherwise I would only have build a nice paint by number pedal.

A really big THANKS to everyone that have worked hard to make this project happen, this is fantastic.

I'm going to upload a few pictures soon today and eventually I will do some soundclips or video but right now I don't have a setup for recording.

[Vince_b]

The pictures:

[R.G.]

So, I've just soldered a tranny in there and that WORKS!!
...
I'm going to upload a few pictures soon today and eventually I will do some soundclips or video but right now I don't have a setup for recording.

It just work?  Kewl!!

By the way, that's a nice, tidy build. You do good work.

[pinkjimiphoton]

The pictures:

vince, that's awesome!!! so glad another one lives, and man, it looks great!!

[artifus]

ditto. inspiring work, vince. second pcb run? modern upgrade news?

[digi2t]

Check the QF+1, and the associated resistors/caps/voltages as well. This is an output amplifier that is fed from the two filters, so it might be here as well.

DINO YOU'RE THE MAN!!
You just made me realize how stupid I can be sometimes... For some reasons, I thought that QF+1 was an optional part, something to use only for some kind of mod to get it closer to the orignal. I really don't know where I got this from.
So, I've just soldered a tranny in there and that WORKS!!
Although it is a really stupid mistake, I'm kinda glad that it didn't work at first. My little troubleshooting odyssey made me take the time to understand the basics of how this circuit works. Otherwise I would only have build a nice paint by number pedal.

A really big THANKS to everyone that have worked hard to make this project happen, this is fantastic.

I'm going to upload a few pictures soon today and eventually I will do some soundclips or video but right now I don't have a setup for recording.

Oh dude, I'm just a small part of a really great group here. Most of what I know has been handed down to me from some really keen minds (pun fully intended  ).

The reason why that transistor (and the related resistors/caps) is labelled QF+1 is because that circuit is not located on the main board in the original units. It's a turret board, that seems to have been an after thought during production. Nonetheless, it's integral to the units operation.

Do yourself a favor though, either ditch RF26 resistor for a small 50K trimmer, or a resistor somewhere in the neighbourhood of 15K to 22K (test using a temporary pot in it's place). You'll see, compared to the fuzz, the clean FFM signal is really loud. So loud in fact, you won't be able to balance between it, and the bypassed volume, even with the bypassed volume at max. Especially with modern pickups being more powerful, the clean signal hits the filters so hard, that it distorts the filters. Also, modding this resistor will also set the fuzz volume slightly higher, allowing you to be able to bring the fuzz down via the fuzz knob. Otherwise, you'll find that the fuzz will more than likely stay cranked all the time, yet always be weaker than the clean FFM volume. This is THE most vital mod that Jimi and I have found to make this unit REALLY, REALLY nice/usable.

You can also wire a 50K pot in here as well, and mount it outside, if you desire. This will allow you to fine tune the clean FFM signal at any time, without having to open the unit. This would be useful if your signal chain changes often, and you need to tweak the unit.

That, and switching the slow/fast speed switch around, if you wish. Easy mod, I wrote up on it, http://www.diystompboxes.com/smfforum/index.php?topic=95132.140, plus picture of the PCB mod.

Just out of curiousity, which method did you use to tune it? Did you happen to use my "quick and dirty" set-up method, by setting up the trimmers via measuring the resistances (near the bottom of this page; http://www.diystompboxes.com/smfforum/index.php?topic=95132.120 )? It would be great if someone else could validate the procedure. If you could, and then compare yours to my Youtube videos, that would wrap up that issue.

Other than that, enjoy your new Phase II clone. Really nice clean build, to boot. I'm sure you'll have fun with it.

Cheers,
Dino

[Vince_b]

Thanks for all the kind words guys.

Oh dude, I'm just a small part of a really great group here. Most of what I know has been handed down to me from some really keen minds (pun fully intended  ).

I see what you did there 

I will do both mods (RF26 and slow/fast switch)  when I will have some time.

Yes, I used your "quick and dirty" set-up method and as far as I know it worked well. Eventually I will do a "side by side" comparison by listening closely to your youtube video. But before that I will have to go to ABRA to buy the right pot for the expression pedal because right now I have to move it by hand.

[pinkjimiphoton]

hi vince,  you definitely need the r-26 mod.

on my original, i am gonna disconnect the balance pot and mount it there so i can tweak it.

it really brings the unit to life. the ffm is unusable without the fuzz on otherwise, and the fuzz sounds really weak.
this will phatten it up and is highly reccomended.

i am so psyched to have watched this develop...looking forward to the revised boards.

i still need to populate and build mine, but the damn eyes are so buggy i'm a little aprehensive. hard to solder when ya can't see stuff.

[Govmnt_Lacky]

Awesome build Vince 

Would you mind sharing what size and type enclosure you used here?

[Vince_b]

Would you mind sharing what size and type enclosure you used here?

This is a Hammond 1590D. It fits perfectly.

[Keppy]

Would you mind sharing what size and type enclosure you used here?

This is a Hammond 1590D. It fits perfectly.

Yeah, the prototype build was in one of those, and R.G. based the new boards around the dimensions of that enclosure. Nice work Vince!

[Ry]

Hey guys, I'm still working on my clone...but I just took the cowards way out as I keep working.  I found one on the bay for a very reasonable price!  I can't believe that I actually bought a real one of these things, I've been on the hunt since the mid-90's.    

I suspect that there isn't anything more that can be learned from another vintage unit, but if there is any investigation left to be done, let me know.  I should be getting it late next week.

[Vince_b]

Hey guys, I'm still working on my clone...but I just took the cowards way out as I keep working.  I found one on the bay for a very reasonable price!  I can't believe that I actually bought a real one of these things, I've been on the hunt since the mid-90's.   

You are really lucky to have found one original for a good price! But don't use it as an excuse to not finish your clone 

Those pots are made by P.E.C.. I use the long shaft version, which I cut down to size. I also use the flat shaft style pinion gear, with the circlip. I make the groove for the circlip with a Dremel.

I went to ABRA yesterday and bought the pot. I will cut the shaft and grind it to make it a D-shaft but I'm not sure about how to fit the circlip. I've never worked with that before and I'm totally clueless about how it should fit on the shaft. I get the fact that I have to cut a groove for it but I still don't know how I'm supposed to mount it on the shaft of the pot.

[digi2t]

I went to ABRA yesterday and bought the pot. I will cut the shaft and grind it to make it a D-shaft but I'm not sure about how to fit the circlip. I've never worked with that before and I'm totally clueless about how it should fit on the shaft. I get the fact that I have to cut a groove for it but I still don't know how I'm supposed to mount it on the shaft of the pot.

First, you need to cut your shaft. The total length of shaft should be the length of the gear + 1/16 inch for bushing clearance + 1/8 inch for circlip clearance. Read below for details.

Whatever you do, DO NOT use a grinder to flatten the shaft. Use a file, and go slow, until you can get the gear on snug. Also, when you flatten the shaft, do not file all the way to the pot`s bushing. Leave about 1/16 of an inch, so the gear doesn`t rub on on the bushing when you get the gear on all the way. I jig the shaft in a vise, with just a bit of the radius showing parallel above the top of the jaws. That way, when I file, I can see if I`m straight all the way across.

Taking into account the 1/16, cut the shaft about 1/8 to 3/16 past the end of the gear. This will give you room to make the groove for the circlip. To make the groove, score the shaft so the circlip will nestle up against the end of the gear, when the gear will be completely seated on the shaft. To score the shaft, I use a Dremel with a small thin cutting disc. A small, knife edged file can be used as well. Don`t go too deep, you just need enough of a groove to keep the clip on there.

Hope that helps,
Dino

[Vince_b]

Thanks Dino, this is a really detailed explanation. But the only part that keeps bugging me is how to insert the circlip. I just have to cut a groove (at the right place) all around the flattened shaft then I should be able to push the circlip from the top of the shaft to the groove that I've just made? Or should I cut the groove only on the flat surface of the shaft?
Sorry if it sound stupid but before today I didn't even knew what a circlip was.

[digi2t]

No worries man. Make the groove on the around the round part of the shaft. You won`t need to groove the flat part. Then just work the clip over the end of the shaft, and push it down into the groove.

If by chance you find that the clip is a little loose, take it off, GENTLY squeeze it closed again with a pair of pliers, and try again. Sometimes, if you work them too hard, they tend to open up a bit. A little squeeze tends to solve the problem.

[Vince_b]

I have made the custom pot today.



The lug that I have labelled "1" is the one where I should wire the ground, right? Or should it be t he other way around?