#1
Ok, so I found out GB&C is kind of a ghost town (or ghost forum) and I can't get any help there.

So now I'm counting on the good old GG&A to enlighten me!

Some background info:

I've been modding my Valve Junior, added a tube, put it in a new chassis, etc. Today I finally got to fire it up and test it. Of course, it didn't work. No surprise there.

After some debugging, I noticed I forgot to connect the EL84's screen grid to the HV supply, so I fixed that.

When I fired it up, R10 (the first resistor after the reservoir cap) started getting REALLY hot. I thought that's really odd, since it's higher value than standard (330R, 5W vs 220R, 3W standard). After removing the connection to the screen grid, it didn't get hot anymore. Also interesting, with the connection to the screen grid on, the caps drain properly. With the connection open, I have to drain them manually (yay, sparks!). Heaters & HV supply voltages are fine. There's a faint hum coming from the speakers.

Then I noticed I accidentally wired the cathode of the power tube to the ground. I figured this is pretty bad, but does anyone know for sure? I would think this would cause tube death, but it's still making some faint humming so I don't think the tube is dead.

So there you go, that's the story of my VJ and me. Anyone have any ideas for fixing her?

Here's the most recent schematic:


tl;dr: modded VJ not working, does a shorted cathode cause tube death?

further reading in case you really like reading about my broken amp:

Thread in GB&C:
https://www.ultimate-guitar.com/forum/showthread.php?t=1356957

VJ thread I totally hijacked:
https://www.ultimate-guitar.com/forum/showthread.php?t=1354154&page=3&pp=20
Gear:
- Bugera 333
- VJ & VJ cab
- Jackson JS30
- TS9

Bugera Users Militia. We are horrible people. With a sprinkler fetish.
~ BUM: For all things extinguishing

Rackmount Tube Amp Project <<< Updates!
#2
have you tried sewatt.com?
I'm an idiot and I accidentally clicked the "Remove all subscriptions" button. If it seems like I'm ignoring you, I'm not, I'm just no longer subscribed to the thread. If you quote me or do the @user thing at me, hopefully it'll notify me through my notifications and I'll get back to you.
Quote by K33nbl4d3
I'll have to put the Classic T models on my to-try list. Shame the finish options there are Anachronism Gold, Nuclear Waste and Aged Clown, because in principle the plaintop is right up my alley.

Quote by K33nbl4d3
Presumably because the CCF (Combined Corksniffing Forces) of MLP and Gibson forums would rise up against them, plunging the land into war.

Quote by T00DEEPBLUE
Et tu, br00tz?
#3
Quote by Dave_Mc
have you tried sewatt.com?
Nope, I'll give it a try, thanks.

Although, I'm a bit disappointed that nobody at UG seems to know if shorting the cathode on a power tube makes it push up daisies.
Gear:
- Bugera 333
- VJ & VJ cab
- Jackson JS30
- TS9

Bugera Users Militia. We are horrible people. With a sprinkler fetish.
~ BUM: For all things extinguishing

Rackmount Tube Amp Project <<< Updates!
#5
Quote by stykerwolf
^ hey what happened to your Ahmedinajad quote in your signature?

Um, you added another tube... cool but what's with the 3 volume pots?
It doesn't have any volume pots, only gain pots.

Basically, for tweakability and because I had spare pots laying around.
Gear:
- Bugera 333
- VJ & VJ cab
- Jackson JS30
- TS9

Bugera Users Militia. We are horrible people. With a sprinkler fetish.
~ BUM: For all things extinguishing

Rackmount Tube Amp Project <<< Updates!
#6
i swapped it for this one

and yeah, sewatt seems to be pretty good. you have to register to even see the forums, but it's worth it.

did you change the rectifier on yours? it looks a bit different from the stock one, if i remember correctly.
I'm an idiot and I accidentally clicked the "Remove all subscriptions" button. If it seems like I'm ignoring you, I'm not, I'm just no longer subscribed to the thread. If you quote me or do the @user thing at me, hopefully it'll notify me through my notifications and I'll get back to you.
Quote by K33nbl4d3
I'll have to put the Classic T models on my to-try list. Shame the finish options there are Anachronism Gold, Nuclear Waste and Aged Clown, because in principle the plaintop is right up my alley.

Quote by K33nbl4d3
Presumably because the CCF (Combined Corksniffing Forces) of MLP and Gibson forums would rise up against them, plunging the land into war.

Quote by T00DEEPBLUE
Et tu, br00tz?
#7
Quote by Dave_Mc
i swapped it for this one

and yeah, sewatt seems to be pretty good. you have to register to even see the forums, but it's worth it.

did you change the rectifier on yours? it looks a bit different from the stock one, if i remember correctly.
The topology should be the same, I just it in did the schematic in an (unconventional) way that more closely represents the way the actual layout is.
Gear:
- Bugera 333
- VJ & VJ cab
- Jackson JS30
- TS9

Bugera Users Militia. We are horrible people. With a sprinkler fetish.
~ BUM: For all things extinguishing

Rackmount Tube Amp Project <<< Updates!
#8
oh ok, sure.
I'm an idiot and I accidentally clicked the "Remove all subscriptions" button. If it seems like I'm ignoring you, I'm not, I'm just no longer subscribed to the thread. If you quote me or do the @user thing at me, hopefully it'll notify me through my notifications and I'll get back to you.
Quote by K33nbl4d3
I'll have to put the Classic T models on my to-try list. Shame the finish options there are Anachronism Gold, Nuclear Waste and Aged Clown, because in principle the plaintop is right up my alley.

Quote by K33nbl4d3
Presumably because the CCF (Combined Corksniffing Forces) of MLP and Gibson forums would rise up against them, plunging the land into war.

Quote by T00DEEPBLUE
Et tu, br00tz?
#9
Definitely trying sewatt.
Gear:
- Bugera 333
- VJ & VJ cab
- Jackson JS30
- TS9

Bugera Users Militia. We are horrible people. With a sprinkler fetish.
~ BUM: For all things extinguishing

Rackmount Tube Amp Project <<< Updates!
#10
I'm an idiot and I accidentally clicked the "Remove all subscriptions" button. If it seems like I'm ignoring you, I'm not, I'm just no longer subscribed to the thread. If you quote me or do the @user thing at me, hopefully it'll notify me through my notifications and I'll get back to you.
Quote by K33nbl4d3
I'll have to put the Classic T models on my to-try list. Shame the finish options there are Anachronism Gold, Nuclear Waste and Aged Clown, because in principle the plaintop is right up my alley.

Quote by K33nbl4d3
Presumably because the CCF (Combined Corksniffing Forces) of MLP and Gibson forums would rise up against them, plunging the land into war.

Quote by T00DEEPBLUE
Et tu, br00tz?
#11
you need a resistor on the cathode of the EL84. and i said a few things in ur gb&c thread. it's hard for me to post answers right hwen you post, because you're posting at 7AM my time.
Call me "Shot".

ShotRod Guitar Works

Custom Hand-wired Amplifiers and Effect Pedals.

Est. 2007


Source to everything I say about Guitars, Pedals, and Amplifiers: I make them.


UG's Best DIY PedalBoard
#12
Quote by ECistheBest
you need a resistor on the cathode of the EL84. and i said a few things in ur gb&c thread. it's hard for me to post answers right hwen you post, because you're posting at 7AM my time.
Ahh, those damn timezones..

Anyway, thanks for the help!
Gear:
- Bugera 333
- VJ & VJ cab
- Jackson JS30
- TS9

Bugera Users Militia. We are horrible people. With a sprinkler fetish.
~ BUM: For all things extinguishing

Rackmount Tube Amp Project <<< Updates!