Build Your Own Clone Message Board

I built the ESV Fuzz kit and tried it out with the generic transistors to do the testing. All testing checked out OK so I plugged it in to my rig. It worked, sounded crappy, but it's the transistors that sound crappy. I put the AC127s in and now it won't work. They are in the right way, I've checked it 100 times (the crimped sides are away from the tab on the socket). Are they dead or what? What's my next step. Is there a way to test them? Thanks.

Before you go into a full on freak-out, take a moment, take some pictures of the top of the board, the bottom of the board and all of the wiring. Post the pics here so we can take a good look at your build and see what is happening. Chances are there is a problem somewhere on the board.
-P

But the crappy trannies work and the good ones don't. That tells me the circuit and wiring are OK.

Not necessarily. You are making a great deal of assumptions. Post pics and we can help from there. One thing that you are telling us is that "the crappy trannies work and the good ones don't" The 'crappy' transistors will still make a decent fuzz. SO if it sounds awful with the 'crappy' transistors then there is possibly a problem with the build.
-P

Looks like I melted a wire when I re-flowed all the joints. I haven't put the
back on so a short isn't the problem.

Ok, good a few things to check:
1. On your footswitch Lug 5, check to be sure to clip the little strands of wire that are sticking out (they may be causing a short)
2. Check all of the leads on the Power jack. I can't tell from the picture if any of them are shorting to each other.
3. Does the LED light?
4. Have you biased the circuit using the trim pot? If so, did you use a Digital Multi-Meter or just your ear?
-P

Also, I think the Transistors may be backwards. I know you said that you checked them 100 times. But from what I can see in the manual, the way you have them look backwards.
-P

No short on lug 5
No short on power Jack
The LED does light but no signal
I biased with my Fluke 177 and by ear
Tried the bias pot from full CW to full CCW
I'm sure the trannies are in correctly, but tried them the other way. Still no signal.

Also I did all the tests in the instructions. Continuity and voltages are correct and I'm getting bias voltage on the collector on Q1.

Just to clarify, because you wrote Q1, the trimpot sets the bias of Q2. What range of voltage readings are you getting at the collector of Q2? Is the trimpot adjusting the voltage?

Crap, I meant Q2. Full CCW I get 3.12. Full CW I get 9.46 which is full voltage of the battery.

Test the readings again with Q2 out of the socket. Keep Q1 in.

With Q2 removed: full CCW I get 9.44, full CW I get 9.47

Anyone? I need help with my $100 paper weight.

New development. The trouble shooting guide says I should get bias voltage at the collector of Q2 and the end of the 470 ohm resistor, but I get 9v on both ends of the resistor. Looking at the schematic, I don't even see how that's possible.

Is that with the transistors in or out? In fact check the voltages again with both sets of transistors in and with them out.

Wondering if your AC127s are shot.

That's with the transistors in. I'll check it again later with them out. What's my option if they are bad, buy a new pair?

If they are bad, then BYOC will swap them for you. You just need to contact Keith Directly.
-P

With both trannies out Q2 collector reads 9.46v. So does the base. Q1 collector also reads 9.46v.

It started working. I put the 127s back in for the 20th time and it started working. Now I'm afraid to touch anything. Now my problem is it won't bias below 5.9v. I see from another thread that I probably need a 50 ohm trim pot, correct?

Yes, a 50K Trimmer should help. You may have a cold solder joint or not so good connection somewhere. Try reflowing all the solder points.

I did that already, but I'll do it again. There does seem to still be a problem because I could get it to bias down to 3 something before.

The transistor pins my not be making good contact with the sockets, be sure with those long leads that they are well seated.
-P

I've reflowed all the solder joints and it's still acting crazy. It worked for a while today and sounded great. I'll set the bias with my Fluke at 4.5v and test it again and it's at 6.1, or 7.5 or whatever. It acts the same with both sets of trannies so I don't think they are defective. I'm going to order some sockets and change them and maybe the trimmer. I don't know.

It works now and it sounds amazing. I have an Analogman 2SB Sunface and the BYOC beats it. I changed the two tranny sockets and the bias pot to a 50K. I think it was the sockets, the new ones are harder to get the tranny legs in than the original ones, better grip I guess.

I hope it keeps on working, I plan on doing the fuller mods to it and putting the bias trimmer on the outside. A 5 knob FF!