EL34 Rockster Help

[Ian444]

Tony, the amp will work fine without that cap, just lower output that's all. Won't affect the bias or anything. Just take it out if you want to have a listen to the amp.

BTW glad you found the problem.

[M Fowler]

Is the cap wired in the correct orientation?

[dorrisant]

The ground side of the cap was toward the bottom of the pic that I posted earlier... connected to the gold anodized Dale 1ohm.
There was no smoke at the lower light bulb dropped voltages. I thought that maybe the cathode resistor might be dropping too much voltage for the cap, especially when the bias is adjusted so low... like 400ohms and a higher B+.
I could be wrong... but I'd rather be aware of that fact, the being wrong in general. It keeps my eyes open to my mistakes and impresses the lessons learned.
I will get a new cap at lunch and try to get it in there tonight... maybe. Gotta spend some time with my peeps or they will revolt! You guys probably know something about that kind of stuff too. Gotta earn the right to spend some more time on this project.
I will post what I can when I can...
Thanks guys,
Tony

[Cliff Schecht]

Glad you figured out the issue! I've done essentially the exact same thing where something in a build is messing up/smoking but you can't find it. Sometimes you just gotta plug everything in and let it do whatever it's going to do, even if it is blow a part or two. Just be glad it was something simple to fix.

FWIW I use the same method of tapping the plate resistor leads with my DMM to see if an amp is making sounds at different stages of the preamp. Nothing wrong with doing this (sort of a cheap audio probe really) and you don't have to whip out the oscope to debug..

[dorrisant]

I knew I did something wrong... I left out the ground wire that goes between the PI and the output tubes... the one that drops off of the 220k resistors. I checked the voltage across the cathode bypass cap (100v) as I switched it off of standby. It was quickly rising up to about 200v before I put it back in standby. I ran the wire and checked it again... About 35v. So the original 50v rating would have been fine.
I had also terminated the input jack with the wrong terminal... straightened that out and heaven is now ported all the way to the speakers! Absolutely the best clean sound I have ever played. Although I do get a bit of fizzyness when I max out the volume... Time to try out some good tubes!
Here is an updated pic of the PS... and a far as noise... Dead quiet! With the volume set at 12:00 and the guitar turned all the way up, you can't hear the amp at all until you touch the guitar. So I will leave it as is for a while.
[IMG768]http://i946.photobucket.com/albums/ad30 ... 61849_.jpg[/img]
Here's the startup chart, hope this might help someone else someday...
[IMG:697:767]http://i946.photobucket.com/albums/ad30 ... 61881_.jpg[/img]
I will post some sound clips later... right now I have some caps to break in...
Thanks to everyone who took the time to read this,
Tony

[ampgeek]

Awesome Tony!!
Persistance and patience...and a little willingly provided guidance from your bretheren....is all that it takes to become satisfied.

Well...at least in this hobby anyway!!

Enjoy,
Dave O.

[M Fowler]

Good job on getting it going.

Take some time and carefully go over everything to make sure you absolutely have it wired correctly.

Mark

[dorrisant]

Thanks again to all. Another change... Wired the cut pot the other way. Now it cuts as you turn it clockwise. I will let the caps burn in and then get some reverb in this jewel!

Tony

[Cliff Schecht]

It looks a LOT cleaner in the power section too. Great job!