Ludwig Phase II Clone Tech Notes

[pinkjimiphoton]

i'm telling ya,. once i get the clone of my own built, i may ditch the original, too...lol.

naaaah...maybe donate it to the rocknroll hall of fame or something..this thing needs to be appreciated!!

sorry i lost track of this thread, for some reason i wasn't being notified of new posts...very weird!!

keppy, anything i can do, say the word...i'll break the box open and have at it.

thanks to all who participate in resurecting this here behemoth!!!!

[Keppy]

Did a little tinkering. You should be able to trigger the flipflop manually.

If you pull out Q2, and connect one lead of a 4.7K resistor to the B2 pin, you should be able to trigger a flip by touching the other end of the resistor to the B1 pin or to ground.

That worked! So...what does that mean?

Each flip moved the voltage on the two test pins between .06v and ~15.9v. What does that say about the problem? Leaky UJT? Coupling cap issue? Seems like I'm missing that spike of current that's supposed to happen.

[Keppy]

Crap, I forgot that I measured 15-16v between the collectors in the flip-flop even when they both measured .06v to ground. UJT working too fast? Timing cap/resistor issues?

Jimi/Dino, could you verify some values for me? R1-12 and C1-5 on the console board. Every measurement I take shows the components to be operational, and yet I don't have animation. I have verified my build against the schem, so I suppose I should verify the schem against your units. Maybe start with R7 (listed as 220).

[Keppy]

control board transistor voltages all sliders @ min, bypass on, fx on

q2 is oddball, it has TWO BASES
i don't know what the first terminal is, so...

?   7.2 - 4.9 keeps cycling
b1  14.4
b2  .3

It seems like whatever's happening with the rest of the circuit, my B1 & B2 voltages should match Jimi's, right? Doesn't the 7k internal resistance of the UJT create a basic voltage divider with R6 & R7? Ignoring the tiny R7 for a moment, shouldn't a 10k and a 7k dividing a 36v drop result in 14-15v no matter what? Yet I'm getting only 2.4v off the 10k (and hence at B1), leading me to believe that the internal resistance of the UJT is falling when I power up the circuit, to much less than 1k. Is it fried?

[digi2t]

 
I believe there is a typo on the schem. C3 is listed as .01uF, but my little fishy in the tank is wearing 1uF colors (non-polarized)  . The capacitor colors are (tropical fish) Brown, Black, Orange, White, Red. My online calculator tells me 1uF/250V, and not .01uF as stated in the schem. Try that. 

Here is the list you requested, this is based on visual color code confirmation;

R1 - 47K
R2 - 100K
R3 - 1M
R4 - 500K TRIMMER
R5 - 10K
R6 - 10K
R7 - 220R
R8 - 47K
R9 - 4.7K
R10 - 4.7K
R11 - 4.7K
R12 - 47K

C1 - 2.5uF/64V (Polar)
C2 - 1uF/40V (Polar)
C3 - 1uF/250V (Non-polar)
C4 - 470nF/250V (Non-polar)
C5 - 470nF/250V (Non-polar)


There you go Kep, maybe we found your fly in the ointment. Just out of curiousity, would Q1 have been damaged if a 1K resistor had been used, instead of a 1M?

Awaiting with bated breath.....

[R.G.]

That worked! So...what does that mean?

Each flip moved the voltage on the two test pins between .06v and ~15.9v. What does that say about the problem? Leaky UJT? Coupling cap issue? Seems like I'm missing that spike of current that's supposed to happen.

That's what that means - the flipflop works if you can manually trigger it, so there is something that's a problem with the UJT. It could also mean the UJT is running way faster than it's supposed to.

Crap, I forgot that I measured 15-16v between the collectors in the flip-flop even when they both measured .06v to ground. UJT working too fast? Timing cap/resistor issues?

If the flipflop is working, there will always be 15-16V between the two collectors, because one will be at 15-16V, and the other will be at nearly ground; they just change positions too fast to see with a meter. Both positions produce the same voltage, but alternating polarities. Here's a thought - measure the difference between the two collectors on an AC scale. This puts a capacitor in series inside the meter to keep the DC out. If you get a significant reading, then they're flopping but too fast to read on DC. Works sometimes.

It seems like whatever's happening with the rest of the circuit, my B1 & B2 voltages should match Jimi's, right?

They should be similar. "Match" is too harsh a word to use on things like JFETs and UJTs. 

Doesn't the 7k internal resistance of the UJT create a basic voltage divider with R6 & R7? Ignoring the tiny R7 for a moment, shouldn't a 10k and a 7k dividing a 36v drop result in 14-15v no matter what?

For DC, yes. If you opened the emitter to preclude the UJT from cycling or latching on, you should see that. However, if you're working with only a meter, not an oscilloscope, then what happens with AC waveforms is too fast for the meter to tell you much unless you really understand what the meter is doing. Analog meters average the incoming waveform and tell you the average because of the inertia of the meter movement. Digital meters may average, may sample, may just get confused.

For debugging mixed AC and DC cases, you really need an oscilloscope. We'll figure ways to work around this. Actually, for this setup, you could use one of the sound-card oscilloscope programs if you protected the inputs from the 35V.  It would show you the ramp/fall on the timing cap OK. Might miss the spikes on the bases, as those are *fast* transitions.

Yet I'm getting only 2.4v off the 10k (and hence at B1), leading me to believe that the internal resistance of the UJT is falling when I power up the circuit, to much less than 1k. Is it fried?

UJTs are supposed to have a trip-over mode. If they stay latched on, then the resistance stays low. A triggering problem on the emitter would do this to a working UJT. This is what I have been suspecting ever since you posted your voltages - that the UJT is either not recovering from the first trip-over or is cycling so fast that you can't see it.

I believe there is a typo on the schem. C3 is listed as .01uF, but my little fishy in the tank is wearing 1uF colors (non-polarized)  . The capacitor colors are (tropical fish) Brown, Black, Orange, White, Red. My online calculator tells me 1uF/250V, and not .01uF as stated in the schem. Try that.

If C3 were too small, it could keep the flipflop from triggering on the spikes from B2. Worth a try.

I suspect from the history that the schematic was drawn and printed up early on, and final tinkering was done on the production line that did not match the printed schemos. It used to take a long time - months! - to get printed stuff done, and for short-run projects like this, they'd have done the printing, then found out that they had to modify it in actual production. That matches the add-on amplifier too. We may find several such issues.

In fact, it would be really useful if someone who has a real unit would just check out the whole schematic for parts values. We now have three places where things on a real board do not match the schemo; the amplifier, the 1M/150K and now C3. It's a lot of work, but if you were so inclined... 

Just out of curiousity, would Q1 have been damaged if a 1K resistor had been used, instead of a 1M?

Maybe, but I don't think it's likely. Not with a couple of 500K pots in the emitter. Maybe if both were turned to zero. Maybe.

[pinkjimiphoton]

hi guys.

that's it...i'm gonna open up mine shortly and type in the value on every single cap and resistor on the unit. i'm in the middle of doing a couple mods on some of my pedalboard pedals (i figured out a way to make a behringer vd1 not suck!! lol...and STILL be quieter than an EH BMP)

give me a little bit.

maybe we can make a deal...as dino's unit is already apart, maybe he can do the console board, and i'll do the fall board?

that way i don't have to dissassemble the whole bloody thing again.

it's 3:09 ct time...gimme about an hour, and i'll get on it.

[digi2t]

maybe we can make a deal...as dino's unit is already apart, maybe he can do the console board, and i'll do the fall board?

You're on brother! I'll try and get them all this afternoon. R.G.'s right (what else is new  ), a thorough perusal of all the components is in order. It's just not right that Kep's got so much trouble getting it going, unless the trannies are to blame. Let's beat this sucker into submission!

All wars are civil wars, because all men are brothers.
FRANCOIS FENELON

[pinkjimiphoton]

time to kick a little ass, and chew a little bubblegum bro.

i dunno about you, i'm all outta bubblegum, so....

it's time to put the fear of god into these units, and make 'em give up their fuggin' secrets so their occult asses can live again!!

let the measuring commence!!

thanks dino!!

[Keppy]

Here's a thought - measure the difference between the two collectors on an AC scale. This puts a capacitor in series inside the meter to keep the DC out. If you get a significant reading, then they're flopping but too fast to read on DC. Works sometimes.

I'll try that.

Doesn't the 7k internal resistance of the UJT create a basic voltage divider with R6 & R7? Ignoring the tiny R7 for a moment, shouldn't a 10k and a 7k dividing a 36v drop result in 14-15v no matter what?

For DC, yes. If you opened the emitter to preclude the UJT from cycling or latching on, you should see that. However, if you're working with only a meter, not an oscilloscope, then what happens with AC waveforms is too fast for the meter to tell you much unless you really understand what the meter is doing. Analog meters average the incoming waveform and tell you the average because of the inertia of the meter movement. Digital meters may average, may sample, may just get confused.

I don't understand why Jimi got stable readings on the bases, then.

Yet I'm getting only 2.4v off the 10k (and hence at B1), leading me to believe that the internal resistance of the UJT is falling when I power up the circuit, to much less than 1k. Is it fried?

UJTs are supposed to have a trip-over mode. If they stay latched on, then the resistance stays low. A triggering problem on the emitter would do this to a working UJT. This is what I have been suspecting ever since you posted your voltages - that the UJT is either not recovering from the first trip-over or is cycling so fast that you can't see it.

I understood that the emitter-B1 resistance went low. The reduction of overall resistance to <1k makes me suspect that the emitter-B2 resistance is also extremely low. I didn't see that mentioned in the description of operation, which is why it appeared to me to be a red flag. I was expecting more like 2.5-3.5k.

I believe there is a typo on the schem. C3 is listed as .01uF, but my little fishy in the tank is wearing 1uF colors (non-polarized)  . The capacitor colors are (tropical fish) Brown, Black, Orange, White, Red. My online calculator tells me 1uF/250V, and not .01uF as stated in the schem. Try that.

Thanks! I'll try swapping that.

We now have three places where things on a real board do not match the schemo; the amplifier, the 1M/150K and now C3. It's a lot of work, but if you were so inclined... 

Wait, what? I don't remember that! Do you mean Console board R3 (1k vs. 1M)? Did I miss something?

[digi2t]

I suspect from the history that the schematic was drawn and printed up early on, and final tinkering was done on the production line that did not match the printed schemos. It used to take a long time - months! - to get printed stuff done, and for short-run projects like this, they'd have done the printing, then found out that they had to modify it in actual production. That matches the add-on amplifier too. We may find several such issues.

Froggin' eh bubba! Here is the list of caps and resistors. Again, a couple of surprises. From the top, console board;
R1 - 47K
R2 - 100K
R3 - 1M
R4 - 500K TRIMMER
R5 - 10K
R6 - 10K
R7 - 220R
R8 - 47K
R9 - 4.7K
R10 - 4.7K
R11 - 4.7K
R12 - 47K
R13 - 100K
R14 - 6.8K
R15 - 10K
R16 - 100K
R17 - 8.2K
R18 - 120K
R19 - 6.8K
R20 - 10K TRIMMER
R21 - 15K
R22 - *** NO RESISTOR ON MY BOARD!!!*** I HAVE JUMPER, NOT THE 100R MARKED ON THE SCHEM.
R23 - 3.3K
R24 - 47K
R25 - 4.7K
R26 - 1.8K
R27 - 4.7K
R28 - 2.2K
R29 - 2.2K
R30 - 2.2K
R31 - 4.7K
R32 - 470K

C1 - 2.5uF/64V (Polar)
C2 - 1uF/40V (Polar)
C3 - 1uF/250V (Non-polar)
C4 - 470nF/250V (Non-polar)
C5 - 470nF/250V (Non-polar)
C6 - 1uF/40V (Polar) I THINK, HARD TO READ, BUT I'M PRETTY SURE
C7 - 1uF/250V (Non-polar) ANOTHER ERROR ON THE PLAN HERE!!
C8 - 100uF/40V (Polar)
C9 - 10uF/40V (Polar)
C10 - 10uF/40V (Polar)
C11 - 100uF/64V (Polar)
C12 - 50uF/40V (Polar)
C13 - 0.22uF/250V (Non-polar)

Now excuse me, as I have to go clean my dagger 

[pinkjimiphoton]

i got slightly tied up, but will be getting to it soon...had a computer meltdown, took til now to get this pos dell to work!!

thanks dino!!

[R.G.]

I don't understand why Jimi got stable readings on the bases, then.

Me neither. I'm in full debug mode, where I suspect everything that even faintly looks/sounds funny. It's a difference, there's trouble there, lessee... what could be wrong?

I understood that the emitter-B1 resistance went low. The reduction of overall resistance to <1k makes me suspect that the emitter-B2 resistance is also extremely low. I didn't see that mentioned in the description of operation, which is why it appeared to me to be a red flag. I was expecting more like 2.5-3.5k.

It's suspicious, all right.

Wait, what? I don't remember that! Do you mean Console board R3 (1k vs. 1M)? Did I miss something?

On one of Jimi's photos, there is a 1M that is not flat on the PCB, and looked to me like it was pasted on after assembly. It was there, and paralleled a 150K. It's here in the forum somewhere.

[pinkjimiphoton]

yes it is....r 33 i believe it is. just cleaning up from the stuff i was doing...modded 3 pedals on my board today, so it's been productive. looking for my little radio shack resistor/cap code thingy so i can read the codes on the resistors. gimme a little bit, i should be starting shortly. sorry for the delay!!

[Keppy]

On one of Jimi's photos, there is a 1M that is not flat on the PCB, and looked to me like it was pasted on after assembly. It was there, and paralleled a 150K. It's here in the forum somewhere.

Oh right, that. Dino said it wasn't in his unit. Since Jimi confirmed the resistors were in parallel, that would only reduce the resistance there to about 130k. Didn't seem worth worrying about, given those two facts. That appears to control the bias to Q7, though, if that appears related to any of my problems.

Speaking of transistor biasing, I keep forgetting to change the 47k on the terminal strip circuit to 68k as confirmed in Dino's unit. I wouldn't bother, but I noticed some nasty distortion when I play really hard, and I was hoping that would help. Now that I think about it, though, if that transistor is biased closer to zero than to the supply, that would actually make it WORSE, wouldn't it? Underbiasing causing clipping of the bottom of the waveform as the transistor turns off, and all that. If that's even where the distortion is happening. Whatever, I guess I should just try it next time the iron's hot.

[R.G.]

looking for my little radio shack resistor/cap code thingy so i can read the codes on the resistors. gimme a little bit, i should be starting shortly. sorry for the delay!!

Bad beer rots our young guts but vodka goes well – get some now. (includes gold/silver/none tolerance bands)
Bad Boys 'Ravage' Our Young Girls, But Violet Gives Willingly
Big Boys Race Our Young Girls, But Violet Generally Wins (more PC)
Badly Burnt Resistors On Your Ground Bus Void General Warranties
Bowling Balls Roll Over Your Grandpa But Victim Gets Well
there are many, many more.

Black = 0
Brown = 1
Red = 2
Orange = 3
Yellow = 4
Green = 5
Blue = 6
Violet = 7
Gray = 8
White = 9

[pinkjimiphoton]

 

lol

i'm on it!!

[digi2t]

My two "bible" pages;

http://www.hobby-hour.com/electronics/resistorcalculator.php for resistors.

and,

http://www.csgnetwork.com/capcccalc.html, or http://www.kpsec.freeuk.com/components/capac.htm for capacitors.

I keep them in My Favorites.

[pinkjimiphoton]

remember too tho, that i modded a couple pieces...

reading values now...gonna take a little bit...stay tuned please  

[pinkjimiphoton]

guys, bear with me...i've found a bunch of discrepancies so far...up to r33...the schematic is afu!!