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I finished up the wiring and adjusted the bias, but I am now not getting any sound coming from the amp when plugged in. The pilot light is on, the tubes are glowing, but no noise from the jack. Any thoughts on how to track down the issue?

So I messed with the resistors on between the bias test points and got some sound. Now it appears my overdrive switch is causing problems.

Is it wired incorrectly?

As far as I can see, the OD switch seems to be wired correctly.
What makes you think the OD switch is the issue?

Also, I would strongly advise you to check all connections.
- Use a digital or printed copy of the lay-out and mark every wire that is in your build. Check them one by one and mark them if they're present. Make sure all wires correspond with the lay-out and none of them have been forgotten. You should be able to tell that right away when you have finished marking the lay-out. Don't forget the jumper wires! They are often overlooked.

- Next, check als solder joints for connectivity. Some of them look to be cold joints but I could be mistaken. Check with a multimeter for connectivity.

- Next, measure all voltages as mentioned in the voltage chart in the manual and post them to this thread. This will give us a better Idea of the problem.

Do you get a proper bias reading on the test points?

Looking forward to your response!

Thanks for replying. With OD off, I have clean guitar sound. I have been cleaning up soldering and checking cable integrity over the past few days and checking connections. I found one missed jumper on v4 from pin3-8, but still having OD issues where it is crackly. I took voltage hoping you can help me track the issue(s) down.

V1
1 - 127
3 - 1.15
8 - 0.88
6 - 111

V2
1 - 158
8 - 4
3 - 1.05
6 - 239

V3
1-242
2-59
3-62
6-166
8-1.5

V4
1-229
2-62
3-65
6-226
8-65

V5
3-447
4-321
5-192

V6
3 - 447
4 - 357
5 - -35

Caps
350 and 450

Bias for T1 red and black is right around 20, but higher on T2 and black.

Thanks again for any help you can offer.

Ethan

[quote="esk1020"]Thanks for replying. With OD off, I have clean guitar sound. I have been cleaning up soldering and checking cable integrity over the past few days and checking connections. I found one missed jumper on v4 from pin3-8, but still having OD issues where it is crackly. I took voltage hoping you can help me track the issue(s) down.

V1
1 - 127
3 - 1.15
8 - 0.88
6 - 111

V2
1 - 158
[b][u]8 - 4[/u][/b]
3 - 1.05
[u][b]6 - 239[/b][/u]

V3
1-242
2-59
3-62
6-166
8-1.5

V4
1-229
2-62
3-65
6-226
8-65

V5
3-447
4-321
5-192

V6
3 - 447
4 - 357
5 - -35

Caps
350 and 450

Bias for T1 red and black is right around 20, but higher on T2 and black.

Thanks again for any help you can offer.

Ethan[/quote]

Alright, thanks for the information!
Your readings for V2 pin 6 and pin 8 are off.
They should be approaching the following values:
Pin 8: 1
Pin 6: 110
This makes sense since you are only getting these problems when the OD is engaged. When the OD is disengaged, Pin 6 and 8 are being bypassed, hence you are not experiencing these problems.

I suspect might be wrong in the wiring there but it's hard to spot it in the pictures you sent because your pictures don't fully include the top half of the amp (including V1). I cannot see where all the wires from V2 go to on the turretboard. Would you be able to send us a picture of that part of the amp?

Also check the values for R11 and R12.
R11 should be 220k
R12 should be 1k.

Looking forward to your response.

[quote="esk1020"]Thanks for replying. With OD off, I have clean guitar sound. I have been cleaning up soldering and checking cable integrity over the past few days and checking connections. I found one missed jumper on v4 from pin3-8, but still having OD issues where it is crackly. I took voltage hoping you can help me track the issue(s) down.

V1
1 - 127
3 - 1.15
8 - 0.88
6 - 111

V2
1 - 158
[b][u]8 - 4[/u][/b]
3 - 1.05
[u][b]6 - 239[/b][/u]

V3
1-242
2-59
3-62
6-166
8-1.5

V4
1-229
2-62
3-65
6-226
8-65

V5
3-447
4-321
5-192

V6
3 - 447
4 - 357
5 - -35

Caps
350 and 450

Bias for T1 red and black is right around 20, but higher on T2 and black.

Thanks again for any help you can offer.

Ethan[/quote]

Alright, thanks for the information!
Your readings for V2 pin 6 and pin 8 are off.
They should be approaching the following values:
Pin 8: 1
Pin 6: 110
This makes sense since you are only getting these problems when the OD is engaged. When the OD is disengaged, Pin 6 and 8 are being bypassed, hence you are not experiencing these problems.

I suspect might be wrong in the wiring there but it's hard to spot it in the pictures you sent because your pictures don't fully include the top half of the amp (including V1). I cannot see where all the wires from V2 go to on the turretboard. Would you be able to send us a picture of that part of the amp?

Also check the values for R11 and R12.
R11 should be 220k
R12 should be 1k.

Looking forward to your response.

[quote="esk1020"]Thanks for replying. With OD off, I have clean guitar sound. I have been cleaning up soldering and checking cable integrity over the past few days and checking connections. I found one missed jumper on v4 from pin3-8, but still having OD issues where it is crackly. I took voltage hoping you can help me track the issue(s) down.

V1
1 - 127
3 - 1.15
8 - 0.88
6 - 111

V2
1 - 158
[b][u]8 - 4[/u][/b]
3 - 1.05
[u][b]6 - 239[/b][/u]

V3
1-242
2-59
3-62
6-166
8-1.5

V4
1-229
2-62
3-65
6-226
8-65

V5
3-447
4-321
5-192

V6
3 - 447
4 - 357
5 - -35

Caps
350 and 450

Bias for T1 red and black is right around 20, but higher on T2 and black.

Thanks again for any help you can offer.

Ethan[/quote]

Alright, thanks for the information!
Your readings for V2 pin 6 and pin 8 are off.
They should be approaching the following values:
Pin 8: 1
Pin 6: 110
This makes sense since you are only getting these problems when the OD is engaged. When the OD is disengaged, Pin 6 and 8 are being bypassed, hence you are not experiencing these problems.

I suspect might be wrong in the wiring there but it's hard to spot it in the pictures you sent because your pictures don't fully include the top half of the amp (including V1). I cannot see where all the wires from V2 go to on the turretboard. Would you be able to send us a picture of that part of the amp?

Also check the values for R11 and R12.
R11 should be 220k
R12 should be 1k.

Looking forward to your response.

[quote="esk1020"]Thanks for replying. With OD off, I have clean guitar sound. I have been cleaning up soldering and checking cable integrity over the past few days and checking connections. I found one missed jumper on v4 from pin3-8, but still having OD issues where it is crackly. I took voltage hoping you can help me track the issue(s) down.

V1
1 - 127
3 - 1.15
8 - 0.88
6 - 111

V2
1 - 158
[b][u]8 - 4[/u][/b]
3 - 1.05
[u][b]6 - 239[/b][/u]

V3
1-242
2-59
3-62
6-166
8-1.5

V4
1-229
2-62
3-65
6-226
8-65

V5
3-447
4-321
5-192

V6
3 - 447
4 - 357
5 - -35

Caps
350 and 450

Bias for T1 red and black is right around 20, but higher on T2 and black.

Thanks again for any help you can offer.

Ethan[/quote]

Alright, thanks for the information!
Your readings for V2 pin 6 and pin 8 are off.
They should be approaching the following values:
Pin 8: 1
Pin 6: 110
This makes sense since you are only getting these problems when the OD is engaged. When the OD is disengaged, Pin 6 and 8 are being bypassed, hence you are not experiencing these problems.

I suspect might be wrong in the wiring there but it's hard to spot it in the pictures you sent because your pictures don't fully include the top half of the amp (including V1). I cannot see where all the wires from V2 go to on the turretboard. Would you be able to send us a picture of that part of the amp?

Also check the values for R11 and R12.
R11 should be 220k
R12 should be 1k.
The problem could be located around that area.

Looking forward to your response.

I am sorry for the double posts. I kept getting error messages, but apparently the post were being posted.
I will report them to the moderators.

I will verify those other voltages. Here is a photo of v2 you requested.

Ethan

Of course, when I went back to verify the voltages, I found that I missed the jumper between the 1k and the 2uf. I put that in and the OD started working. It was squealing at high levels though, so perhaps something is still up. The new pin 6 and pin 8 voltages are 6=89 and 8=.65

My bias is a bit off though as I can get 19-20 on the Test points closer to V6, but the other Test points are in the 40s. Pin 5 on V5 is reading at 192 when it should be (-35), so I wonder if that is what is causing it.

Great! Good to hear that you found the missing jumper.
That would have definetly been the problem causing your problem regarding the OD.

Now, to be honest, I had missed that reading of V5 pin 5 in your previous post.
You are absolutely right though, that is way off.

It is quite strange that one power tubes shows the right values while the other is off.
This is indicating that most of the circuit is correct or else you would also be getting wrongful values on V6.
I then checked the schematics to find out were such a difference could come from and I noticed the two resistors R28 and R29. You HT3 voltage is going through both of these resistors and they are "drained" (or biased) by the wire going to your bias circuit. There is a jumper wire between R28 and R29 which makes sure that both of these connections (which eventually go to pin 5 on V5 and V6) are being biassed. When that jumper is missing, only V6 is getting biassed correctly since V5 is not "seeing" the bias circuit. That must be causing your problem, because V6 is giving you correct readings.

I finally checked your images and noticed that the jumper wire is indeed missing.
Please see the attachment for verification.
I bet soldering in the jumper wire will solve the issue.

Looking forward to your response!

You are awesome. Totally missed that and it solved the issue! Was covered by a wire. Seems to be working now other than a squeal when OD is on and turned up. Also biasing is a bit tricky.

I tried biasing again and can do it through TP1 and black, but not TP2 and black. What could be causing that? I get 20mv and nominal

Well, I tried thinking of something but then I realised you could have broken the tube while that jumper wire was missing.
Just to make sure, it's V5 now that isn't giving you a bias reading, right?
Because that is also the tube that has gotten the incorrect voltages because of the missing jumper.
Have you got some spare tubes to try? You might want to check that first.

Secondly, check all wires on the two power tube sockets, the blue wires going from those sockets to the bias circuit and the connections on the bias circuit itself.
It is very hard to see on the pictures but some connections seem to lack solder, but I could be mistaken.

First try out a new tube. Might solve the issue already.

By the way, out of curiosity are you using the 6V6 tubes?

You are correct that it is V5 that is not giving the bias reading. I will double check the connections and may try flipping the two power tubes to see if that does anything. I will order some new ones as well.

I am using JJ 6V6s Tubes.

So I swapped out the tubes and now I am not getting bias reading on the V6. So I will order a new tube and hopefully that fixes it.

Okay, great. That should be the final issue then.
Please let me know if those new tubes solved the issue.
I am very happy having been able to help you out.
The guys on the forum helped me out a bunch too.

BTW, I am using JJ 6v6s too. Great tubes that fit the amp well. Those are very sturdy tubes that can withstand quite some voltage. Significantly more than some other current production 6v6s. Unfortunately, the voltage you gave that V5 must have been too much to handle, even for the JJs. But hey, that is part of the process! ;-)

Got my new tube in and swapped out some caps for Sozos and it’s working perfectly. Getting approximate voltage readings as well as bias on both power tubes. Thanks again for your help! I certainly learned a lot on this build and look forward to doing another sometime soon.

Ethan

Awesome!
I'm very pleased to hear all is working fine now.
Have fun with your amp!! Doesn't get any better than this mate.