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Ce-2 troubles

Started by arawn, October 11, 2011, 08:23:48 PM

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arawn

October 11, 2011, 08:23:48 PM
Building a bosss ce-2 clone using the tonepad layout here http://www.tonepad.com/getFile.asp?id=101
I have an unaffected signal passing through the circuit the problem seems to be something to do with ic2 or q4 and q5
I have verified that no components are reversed and I have no solder bridges. replacing ic2 changed the voltages some but did not affect the lack of effect.
voltages are as follows
IC1 -  NE5532
1   5.17   8   8.77
2   5.16   7   5.16
3   5.15   6   5.16
4   0   5   5.15

IC2 -  LM358
1   7.46   8   8.73
2   4.29   7   66 mv
3   7.28   6   6.70
4   0   5   3.98

IC3 -  MN3007
1   8.55   8   8.15
2   0   7   8.14
3   4.39   6   8.54
4   .589   5   0

IC4 -  MN3101
1   8.54   8   .587
2   8.53   7   8.40
3   0   6   0
4   0   5   8.45

2N5088
Q1      Q2      Q3                          Q4                            Q5
C   4.08   C   4.37   C   4.16   C   3.85    C   .677
B   4.50   B   4.90   B   3.60   B   4.17   B   35 mv
E   8.66   E   8.66   E   8.63   E   4.17   E   35 mv

"Consistency is the Hobgoblin of Small Minds!"

Gus Smalley clean boost, Whisker biscuit, Professor Tweed, Ruby w/bassman Mods, Dan Armstrong Orange Squeezer, Zvex SHO, ROG Mayqueen, Fetzer Valve, ROG UNO, LPB1, Blue Magic

Quackzed

#1
October 11, 2011, 10:41:35 PM
the 5088s would seem to be reversed... shouldnt the collectors be more positive than their emitters?
not sure just a quick look...
nothing says forever like a solid block of liquid nails!!!

Keppy

#2
October 12, 2011, 12:20:38 AM
It appears to me that you've switched the labeling on some of your transistor leads. On the first three transistors your emitter voltages are mostly right around supply voltage (like the collectors should be). On Q1 & Q2, there is a diode drop from base to collector (like there should be from base to emitter). On Q3, the diode drop is from collector to base. I think it's likely you've mislabeled them, though, rather than inserting them wrong.

I think the problem is in/around Q4. Your Q4 collector should be connected to the same supply as IC4 pin 1 (8.54v). Something's wrong there, since you have only 3.85v. Since Q4 links the LFO to the modulation, I'm guessing that's your problem. Make sure you have that one oriented correctly, and if you don't, swap it out. Also, check the pink trace for continuity. Q5 is an unfamiliar orientation to me, so someone else will have to speak to that.

Also, try turning the rate all the way down and checking pin 7 of IC2. That's the output of the oscillator, so it should sweep, as should the base and emitter of Q4.

Good luck!
"Electrons go where I tell them to go." - wavley

Keppy

#3
October 12, 2011, 12:27:31 AM
I forgot to ask - did you do the vibrato mod? That mod removes the dry signal, so if you turn it on and you hear nothing, then signal is not passing through the delay circuitry. If you turn it on and hear dry signal, then your BBD is working but your oscillator's not causing it to sweep. Two different reasons for passing only dry signal. If you didn't do the mod, then you can check this with and audio probe at pins 7 & 8 of IC3.
"Electrons go where I tell them to go." - wavley

arawn

#4
October 12, 2011, 06:24:18 AM
no mods,
q4 sweeps with the depth pot  and pin 6 of ic2 sweeps with the rate pot.
I replaced q4 and my  voltages came online, and i do have continuity on the pink trace.
whats next?
"Consistency is the Hobgoblin of Small Minds!"

Gus Smalley clean boost, Whisker biscuit, Professor Tweed, Ruby w/bassman Mods, Dan Armstrong Orange Squeezer, Zvex SHO, ROG Mayqueen, Fetzer Valve, ROG UNO, LPB1, Blue Magic

Keppy

#5
October 12, 2011, 11:49:49 PM
What do you mean when you say the Q4 voltages "came online?"

Check that you get sweeping on pin 7 of IC4. Also try an audio probe at pin 3 & pin 7/8 of IC3 (thats the in & out of the BBD). If you have no audio at pin 3, then Q2's probably the culprit. If you have no audio at pin 7/8 (but you do at 3) then the BBD is the culprit. If you have audio all through there but not at the effect out, then take a good look at/around Q3. If you have audio all the way through to the end but no effect, then you have a problem connecting your oscillator to IC4, or with IC4 itself.

Have you used an audio probe before? It's worth rigging one up if you haven't. Personally, I don't bother with modifying a cable, though. I just use a wire, capacitor and jack on my breadboard.
"Electrons go where I tell them to go." - wavley

arawn

#6
October 13, 2011, 07:16:57 AM
pin7 of ic4 does not sweep, I will audio probe later
"Consistency is the Hobgoblin of Small Minds!"

Gus Smalley clean boost, Whisker biscuit, Professor Tweed, Ruby w/bassman Mods, Dan Armstrong Orange Squeezer, Zvex SHO, ROG Mayqueen, Fetzer Valve, ROG UNO, LPB1, Blue Magic

Govmnt_Lacky

#7
October 13, 2011, 07:55:35 AM
Are you getting any fluctuation on your LFO (IC2?) You did not mention above whether or not it is sweeping.

Also, some of your voltages look off. Shouldn't IC1 voltages be around 1/2 of V+? They seem a bit high.

Any noticable differences when you adjust the trimmer?

Good Luck  ;D
A Veteran is someone who, at one point in his or her life, wrote a blank check made payable to The United States of America
for an amount of 'up to and including my life.'

arawn

#8
October 13, 2011, 08:20:42 AM
pin 6 of ic2 sweeps, I just finished audio probing which allowed me to hear the oscillator, but i have no audio on pins 7,8 of ic3
"Consistency is the Hobgoblin of Small Minds!"

Gus Smalley clean boost, Whisker biscuit, Professor Tweed, Ruby w/bassman Mods, Dan Armstrong Orange Squeezer, Zvex SHO, ROG Mayqueen, Fetzer Valve, ROG UNO, LPB1, Blue Magic

Govmnt_Lacky

#9
October 13, 2011, 08:47:32 AM
Charles,

I do remember I had a similar problem in the past. I did a bit of research and found that there were some bad clock chips floating around. The solution was to lift the 3101 Pin 8 out of the circuit and it snapped back to life!

Might be worth a try!

Good Luck  ;D
A Veteran is someone who, at one point in his or her life, wrote a blank check made payable to The United States of America
for an amount of 'up to and including my life.'

Quackzed

#10
October 13, 2011, 12:14:04 PM
i'd still say double check those transistors arent flipped...
nothing says forever like a solid block of liquid nails!!!

arawn

#11
October 13, 2011, 12:49:09 PM
Transistors are oriented per the tonepad layout.
Lifting pin 1 of the 3101 cut all audio output, at this point i think i am going to get a new bbd when i get some more money and try replacing it cause i can hear the lfo ticking with my audio probe and I can't find any other reason why it won't work.
"Consistency is the Hobgoblin of Small Minds!"

Gus Smalley clean boost, Whisker biscuit, Professor Tweed, Ruby w/bassman Mods, Dan Armstrong Orange Squeezer, Zvex SHO, ROG Mayqueen, Fetzer Valve, ROG UNO, LPB1, Blue Magic

Keppy

#12
October 13, 2011, 12:56:18 PM
Don't give up on the BBD just yet. Since you're getting no sweep on IC4, your LFO is disappearing between IC2 & IC4. Check all those components, maybe reflow the solder.

Regardless is oscillator function, though, you should have signal at the output of IC3. The fact that you don't means there's another problem. Did you audio probe the input of IC3 and the emitter of the transistor feeding it?
"Electrons go where I tell them to go." - wavley

Quackzed

#13
October 13, 2011, 01:06:43 PM
maybee also check vb bias, the collectors of those trnsistors (1 2 3 + 4)should be the same as vb off vr3... and the emitters should be close to ground, at least lower than base... in your posted voltages at least, unless the c and e designations are only switched in your post and not in the circuit. if so the vb off vr3 should be able to give @ 4.5v at vr3 center rotation, set it for 4.5v and check the transistors collector voltages
q123+4's collectors should all be the same- @4.5v or whatever you get at vb( off vr3)...

nothing says forever like a solid block of liquid nails!!!

arawn

#14
October 13, 2011, 01:17:15 PM
I got q4 straightened out,
I have lfo function I heard it ticking and checked for sweep when i was audio probing
I did get audio at pin 3 of ic 3 no audio on ic4 or on pins 7,8 of ic3
I have reflowed every joint on the board, i am thinking i just got a bum clock/driver and bbd it's the only explanation left to me.
no worries
"Consistency is the Hobgoblin of Small Minds!"

Gus Smalley clean boost, Whisker biscuit, Professor Tweed, Ruby w/bassman Mods, Dan Armstrong Orange Squeezer, Zvex SHO, ROG Mayqueen, Fetzer Valve, ROG UNO, LPB1, Blue Magic

Govmnt_Lacky

#15
October 13, 2011, 03:09:39 PM Last Edit: October 13, 2011, 03:14:29 PM by Govmnt_Lacky
Quote from: arawn on October 13, 2011, 12:49:09 PM
Lifting pin 1 of the 3101 cut all audio output...

Try lifting Pin 8 of the 3101 as I mentioned above  ;D

EDIT: What are the manufacturers of the clock and BBD? Are they BOTH Matsushida? (Little white "M" on the packaging)
A Veteran is someone who, at one point in his or her life, wrote a blank check made payable to The United States of America
for an amount of 'up to and including my life.'

arawn

#16
October 13, 2011, 04:14:13 PM
yes matsushita, i meant to say pin 8 before and it didn't help
"Consistency is the Hobgoblin of Small Minds!"

Gus Smalley clean boost, Whisker biscuit, Professor Tweed, Ruby w/bassman Mods, Dan Armstrong Orange Squeezer, Zvex SHO, ROG Mayqueen, Fetzer Valve, ROG UNO, LPB1, Blue Magic

Fender3D

#17
October 14, 2011, 05:32:47 AM
Your MN3101 is stuck.
You have no clock on its pins 2 and 4.
Lift Q5, D1 and D2, then add a 22k resistor from pin 6 to pin7.It will "clock" with no modulation, but this will tell if 3007 works at least....
"NOT FLAMMABLE" is not a challenge
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