Back to square one... success! Dumb mistake

[M Fowler]

I do both solder to the pots and once in awhile use the .390 grounding tabs shown below.

Mark

[Randy Magee]

I have some new pots (and a few other parts) in and I will be redoing the grounds to a buss bar not soldered to the pots. My volume pot had some quite strange readings indicting it may have been smoked soldering on the buss. When I'm done I'll post some new pictures as I plan to revisit the wiring on both boards. I might take a few days before I get it done...

[Randy Magee]

Well I'm really embarrassed to say that I had a really dumb wiring error on the board. I revisited the grounding scheme and removed the board and immediately saw my error. Now I can go about my business of finding the best tubes to use, I have a NOS set of Philips EL34s from the '60s that a Dutch buddy gave me. I just need to root around my 12AX7s to find what I want to use. The amp sounds great as it is! Very loud and really pretty quiet even when it's cranked. I ended up using a buss not soldered to the pots, grounded my input jack as well and grounded the output jacks as well. I appreciate everyone's help and suggestions, you've all been very helpful and patient with me. Thank goodness it's been solved and I have a new very good sounding amp!

[sliberty]

Glad to hear you solved it. Congrats!

[Picker]

Excellent!

Glad you finally tracked it down.

[T Wilcox]

Glad to hear its working.
What was the wiring error?

Todd

[Randy Magee]

It was so stupid that I refuse to say...

[T Wilcox]

No worries I am not asking to humiliate you, but knowing what the cause of your amps symptoms could help someone else down the road.
BTW I've made a few stupid mistakes myself on some builds and they were always the ones I learned the most on.

Todd

[Randy Magee]

No worries I am not asking to humiliate you, but knowing what the cause of your amps symptoms could help someone else down the road.
BTW I've made a few stupid mistakes myself on some builds and they were always the ones I learned the most on.

Todd

Originally I wired the bias circuit and the wires to the PI under the board. When I first turned it on and started checking voltages, I discovered a wiring error in the bias circuit and realised that I'd also connected the wires out of the PI as well. To make a long story short, when I turned the board over when redoing the ground buss, I found that I had both signal wires to the power tubes hooked to just one side of the PI... duh! What a bonehead mistake!

[T Wilcox]

Thats not as bad as you make it sound, I bet you never do that again
So hows the amp sounding now? Nice and loud?

Todd

[marcoloco961]

No worries I am not asking to humiliate you, but knowing what the cause of your amps symptoms could help someone else down the road.
BTW I've made a few stupid mistakes myself on some builds and they were always the ones I learned the most on.

Todd

Originally I wired the bias circuit and the wires to the PI under the board. When I first turned it on and started checking voltages, I discovered a wiring error in the bias circuit and realised that I'd also connected the wires out of the PI as well. To make a long story short, when I turned the board over when redoing the ground buss, I found that I had both signal wires to the power tubes hooked to just one side of the PI... duh! What a bonehead mistake!

No need to be embarrassed. We all get a little nervous and overwhelmed on the first couple of builds, and it is almost always a simple mistake like that causing the issues. I knew you would get it eventually.

Troubleshooting is not that much fun, but it helps you learn more about how the amp works then just following the schematic and layout and soldering it together. I imagine by now you have forgotten any frustrations and are enjoying a great sounding amp. If you have a chance post a few clips, would love to hear it. And again, nice looking build.

[Randy Magee]

No worries I am not asking to humiliate you, but knowing what the cause of your amps symptoms could help someone else down the road.
BTW I've made a few stupid mistakes myself on some builds and they were always the ones I learned the most on.

Todd

Originally I wired the bias circuit and the wires to the PI under the board. When I first turned it on and started checking voltages, I discovered a wiring error in the bias circuit and realised that I'd also connected the wires out of the PI as well. To make a long story short, when I turned the board over when redoing the ground buss, I found that I had both signal wires to the power tubes hooked to just one side of the PI... duh! What a bonehead mistake!

No need to be embarrassed. We all get a little nervous and overwhelmed on the first couple of builds, and it is almost always a simple mistake like that causing the issues. I knew you would get it eventually.

Troubleshooting is not that much fun, but it helps you learn more about how the amp works then just following the schematic and layout and soldering it together. I imagine by now you have forgotten any frustrations and are enjoying a great sounding amp. If you have a chance post a few clips, would love to hear it. And again, nice looking build.

This was not one of my first few builds... I just got in a rush, worked while tired... you know the drill. I knew it had to be something simple after patching in another OT and got the same old nasty sound.

You're right about the troubleshooting... it was no fun at all. Had I not decided to redo the grounding scheme and rework the board, I'd probably still be looking for the problem. When I turned the board over, I immediately saw what was wrong and knew it would work when I got everything wired up.

The amp sounds great even with the crud tubes I have in it right now. I may have to try running some 6V6GTs to get the volume down some. I still have to build a cabinet for it and find some less efficient speakers else I'll be deaf in a week. Unfortunately I don't have the capability to make clips, perhaps I can get one of my buds that records a lot to do that.

Anyway, thanks again to the forum for all the help... I think I learned a lot from my mistakes on this amp...

[M Fowler]

Randy,

Great news and glad the amp is working now.

Mark

[Randy Magee]

Randy,

Great news and glad the amp is working now.

Mark

Actually you had an observation that helped me figure this out... remember the wires that were done under the board and you recommended moving them both to the top? When I turned the board over, the mis-wire was glaringly apparent... now on to the cabinet... I have some lovely tiger maple for the cab...

[Gibsonman63]

Glad to hear you got it working.