Vulcan Rat Creation

[duck_arse]

jfra - save me going back over the 3 pages - what transistors are you using? because I see you have mirrored Ben's left-to-right components, but also have reversed his transistors. if you are using 2N****, and he used 2N****, yours should still face the same way as his.

unless I've missed a post on back to fronting the layout.

[Ben Lyman]

Holy carp, Duck! I think you're right, I just looked back and it does appear that the transistors may be in backwards.

[jfrabat]

2N2222

I have to check, but now that you mention it, I think you are right.  IIRC, I set them looking at the board from the top, but the schematic is looking from the. Uttom

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[Ben Lyman]

Felipe, my diylc layout is a veiw from the top looking down on the components, and through them as if you could see the traces underneath. Sorry I thought that was a given but maybe not as clear as I thought.

Anyway, not a big deal, signals is signals and all should flow fine as long as you can unsolder those trannies and flip them around

I would still encourage you to leave out the extra 3 clipping diodes (just for the moment) and see if we can get the main circuit working first. The extra distortion switch is just fluff anyway.

[jfrabat]

I think you are correct...



According to this, the Emitter is facing UP and it should be facing DOWN!  I think I know what happened now...  Because the diagram is in mirror (I built it looking from the BOTTOM of the board, not the top), when I put the transistors in, I put them facing the 100uF cap, but that means it is backwards.

I'll correct them tonight.  THANKS FOR THE HELP!  This helps A LOT to all that helped (Ben, Duck, Rob, and anyone else I have left out)!!!  I hope that's the last of my issues!

Felipe

[jfrabat]

OK, put in new transistors (could not take old ones out without destroying them!).  This is the latest look:





Also fixed a broken cable (ground).  But there is still something off...  I still get no sound.  Tried the sound probe, and looks like Q2 is not amplifying.

New voltages:

Battery: 9.1v

Q1:
E: 0.302v
B: 0.880v
C: 6.05v

Q2:
E: 7mv
B: 0.322v
C: 8.79v

Q3:
E: 0.278v
B: 0.848v
C: 6.43v

[jfrabat]

Well I did fix the Q2 issue now it's amplifying. I got the sound coming all the way out to the output jack on the sound probe but for some reason when I connect the guitar to the circuit and out to the amplifier there's no sound coming out when I activate the circuit ( it works just fine when I bypass the circuit).  I have a couple of video is uploading to YouTube so I can show you what I mean.

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[robthequiet]

<edit, saw the Q2 problem has been solved> Sounds like the bypass switch is our next thing to check. Does the LED still work?

[Ben Lyman]

Ya, what Rob said. Also, a long shot but any chance you are accidentally plugging in backwards? That would allow a bypassed signal to work while engaging the effect would not... I know this because... well, umm.. i've done it many times 

[jfrabat]

Here are the videos:

[Ben Lyman]

it occurs to me now that the pots will probably operate in the opposite direction, are they all set around noon for the test?

[jfrabat]

No, they are at full volume, but yes, they are backwards.  I also checked their operation, and they are working as they should (albeit in the wrong direction).  But the signal is at least as loud as the clean guitar; the amp should pick that up, right?

[Ben Lyman]

Ya that's weird. Maybe the switch is bad or there is a little short caused by a stray wire trimming or solder blob. But I bet you've examined it closely several times at this point, eh?

what is the little alligator clip for in your video? the one that's clipped to the ground of the output jack? Is that part of the signal generator or test probe or something?

[jfrabat]

Ya that's weird. Maybe the switch is bad or there is a little short caused by a stray wire trimming or solder blob. But I bet you've examined it closely several times at this point, eh?

I do have the IN and OUT wires backwards in that traditionally, the IN is at the left and OUT is at the right, and mine are the other way around, but it should not really matter, right?  I will replace them anyway to rule it out, but that should not be the issue...

what is the little alligator clip for in your video? the one that's clipped to the ground of the output jack? Is that part of the signal generator or test probe or something?

It's the ground for the voltmeter; I was also checking voltages.  I am really stumped as to what could be the cause of the sound not making it to the amp...  Especially since I KNOW there is a signal there (checked with the sound probe!).

[Ben Lyman]

can you clip jumper wires onto the switch to bypass it? going from in jack straight to board in and another from board out straight to out jack. that might identify the switch problem if it is that

[jfrabat]

can you clip jumper wires onto the switch to bypass it? going from in jack straight to board in and another from board out straight to out jack. that might identify the switch problem if it is that

I will try this.

[robthequiet]

If the signal can be heard on the tip contact on the out jack, if the switch checks out OK I would look into the output jack having a problem when the plug is inserted. You could also alligator clip the output from the center lug of the volume pot to the guitar cable itself. That way we isolate the problem at jack or switch. edit: if you are getting clean signal, it may not be the jack, but a wiring issue that might be revealed by jumpering around as Ben says.

[jfrabat]

If the signal can be heard on the tip contact on the out jack, if the switch checks out OK I would look into the output jack having a problem when the plug is inserted. You could also alligator clip the output from the center lug of the volume pot to the guitar cable itself. That way we isolate the problem at jack or switch.

Good idea...

[jfrabat]

Tried a new switch, allivators on the jacks, and no change...

Here is the whole circuit:



And the bottom of the board (see any bridges?):



Here are the switch and jacks:

[jfrabat]

Two more and and some voltages:





Batt: 9.1V

Q1:
C: 6.05V
B: 0.88V
E: 0.302V

Q2:
C: 8.85V
B: 0.331V
E: 0V

Q3:
C: 6.43V
B: 0.848V
E: 0.273

Let me know of any ideas...