#1
I just changed all my pre-amp tubes to JJ 12AX7s. I probably played for 2 hours with them, and it sounded amazing.

Then, this morning I was on the lead channel and it just stopped all of a sudden -- no sound whatsoever. I switched to the other channel and both clean and crunch still work great. But no lead channel.

Obviously, I strongly suspect one of the new tubes failed. But which one???

I've been trying to locate a schematic of which position drives what on the 6505+ 112, but I can't ever seem to get a straight answer. It only has 5 pre-amp tubes as opposed to the head, and I think the layout may be different.

I can probably troubleshoot it myself but I was hoping to save some time by not having to wait for the tubes to cool down between each trial -- and just go right to the culprit. Thanks for any help!
Atmospheric dark metal w/ black and death metal influences:
(My Soundcloud page):

Pestilential Flood
#2
Were the old tubes still good? If you still have them, pop them in and see if it works. Or just take one that you know is good and run it through each position.

Or you could try taking the new tubes out one by one and spraying the pins and seat with a liberal amount of contact cleaner and working the tube in and out.
Quote by tubetime86
He's obviously pretty young, and I'd guess he's being raised by wolves, or at least humans with the intellectual capacity and compassion of wolves.


You finally made it home, draped in the flag that you fell for.
And so it goes
#3
Actually, I just found the one. It was V4 (of course, the pain-in-the-ass one behind the reverb tank). My Ruby tubes are all still good, so I put one of those in and the lead channel sprung to life again!

I can't visually see anything wrong with the JJ tube though. Part of me thinks it may not have been pushed up all the way on my original install -- that particular position is very hard to reach and you can't actually see what you're doing because the reverb tank is in the way.

I might try the JJ again just to make sure it has truly failed. Either way, it still sounds amazing; can't really tell a difference with the one Ruby in there.

I'll add this info to the 6505 thread. That particular position only powers the Lead channel. Could be useful to some people...
Atmospheric dark metal w/ black and death metal influences:
(My Soundcloud page):

Pestilential Flood
#5
Well, now I'm not so sure the amp itself isn't causing the problem. The same thing just happened with the Ruby tube in there. I was just playing on the lead channel and pop -- it just went silent. Clean/crunch still works fine. I'll put another Ruby tube in there and see what happens, but if it happens after that, I'm calling Peavey...
Atmospheric dark metal w/ black and death metal influences:
(My Soundcloud page):

Pestilential Flood
#7
LOL - my fault. I pulled the Ruby out and the tip of the glass had broken off. I think I damaged it while re-installing the cover (again, it's a very tight space and you can't see what you're doing). It must have been just ready to fail when I put it in, and then the vibrations of playing caused the glass to break.

Though the JJ wasn't visibly broken. That one must have just been a dud. Still sounds killer with the one Ruby though. Matter of fact, the tone is incredible with the JJs and my recent speaker swap.

Crisis averted!
Atmospheric dark metal w/ black and death metal influences:
(My Soundcloud page):

Pestilential Flood
Last edited by KailM at Feb 4, 2012,
#8
inb4 it breaks again and OP finds another thing he did wrong.
Quote by DeathByDestroyr
What the hell is a G&L.



Quote by Flux'D
Gay & Lesbian I think, the box smelled funny
Greg what did you send me??
#9
OK KailM, glad you got that sorted. Now, on to better things. After breaking that redcoat in a little more starting to dig it? Are you still playing with the back off? How much of a difference did the JJ's make.

Come on brother details details!!! lol (Spend my money for me) haha
#10
Quote by surjer
OK KailM, glad you got that sorted. Now, on to better things. After breaking that redcoat in a little more starting to dig it? Are you still playing with the back off? How much of a difference did the JJ's make.

Come on brother details details!!! lol (Spend my money for me) haha


Still playing with the back off. As soon as I took it off it was like a 75% improvement in tone. A lot of the low end returned, but it maintained that midrange growl. Overall it just has a nice tight, clear, but extremely PISSED-OFF sound to it. (Which is exactly what I wanted in the first place.)

The JJ's just seemed to be the icing on the cake. They took away some of the brightness and darkened it up, while maybe adding some low-end to the chugs. Harmonic content is definitely richer as well.

As for the back being removed, I think it just allows the speaker to move a little more freely; so more low-end. It also has the effect of it sounding louder without truly being louder. I think the speaker is still breaking-in, and I will try re-installing the back after awhile to see what happens. But right now I'm in tone-heaven!
Atmospheric dark metal w/ black and death metal influences:
(My Soundcloud page):

Pestilential Flood