#1
Hey guys I just picked up a used Peavey JSX yesterday and I'm having an issue with the Ultra channel. I tried it out at the sellers place everything sounded great; lots of gain, but after I got it home and then set it up today the Ultra channel sounds more akin to a nice medium crunch.

The amp was retubed a couple years ago but apparently wasn't played much since then. Also, the Crunch channel seems to have the appropriate amount of gain that can be expected from it. Could I have possibly unsettled one of the tubes during transport?

Any help would be appreciated guys, I'm extremely pumped that I was able to find this head and am looking forward to being able to rip it up with it.
Satan. Grant this man the gift of revenge against his foes at the Food Network.
#2
Being a JSX, at some stage you will want to retube it with JJ preamp tubes so you may as well start now. I'd at least buy one to try in each position as a fault finding exercise.
Also you should check that all the tubes are still seated properly. Just pull them out and put them back in one by one.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
#4
The JSX has a tendency towards ice pickiness and they are very sensitive to tube types. The JJ's tame that. With JJ's the JSX is a hard amp to beat.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
#5
All right then, any advice for the power tubes also?
Satan. Grant this man the gift of revenge against his foes at the Food Network.
#6
That's a tougher one. IIRC you can run either 6L6 or EL34 type tubes in those, yeah? I am really impressed by the JJ E34L. They have the midrange bite of an EL34 but a bigger bottom end like a 6L6.
JJ 6L6GC are a mighty fine tube too but I like more midrange in my amps so I'd go for the JJ E34L. Power tubes do make less difference to the amp's tone than preamp tubes though so take a punt, either of those two would be good.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
#8
What about KT77s, I've heard those are a nice change up also?
Satan. Grant this man the gift of revenge against his foes at the Food Network.
#10
Isn't a JSX basically a Triple XXX? Shouldn't be lacking much gain... Do you have any OD pedals lying around? Might try one and see if you can tell a lot of difference with it engaged.

Maybe a problem with your setup as in cab or impedance etc?
#13
Why am I troll, I tried the amp at the sellers and it worked perfectly with tons of gain on tap. I get it home, set it up and it's all but disappeared from the Ultra channel but the crunch channel is fine.

Anyway, thanks for the advice everyone I'll try reseating the tubes and I'll look into ordering some JJs for the preamp.
Satan. Grant this man the gift of revenge against his foes at the Food Network.
#14
Quote by KillRoy Ver 3.0
Why am I troll, I tried the amp at the sellers and it worked perfectly with tons of gain on tap. I get it home, set it up and it's all but disappeared from the Ultra channel but the crunch channel is fine.

Anyway, thanks for the advice everyone I'll try reseating the tubes and I'll look into ordering some JJs for the preamp.


Ignore the guy, he is a troll and has posted stupid shit for two threads now.

ESP LTD F-50 + Tonezone
Cort EVL-Z4 + X2N
Cort EVL-K47B

Marshall Valvestate 8100
Randall RG1503
Bugera 333
Peavey Rockmaster preamp

Line6 Pod X3
#16
TS, first reseat the tubes, if you for have a problem with the tone then I wouldn't replace the tubes until they are bad. It is possible that one of the tubes just randomly went, but I'd try other things before replacing the tubes. Still a good idea to have some spares though, but I'm of the mind that if it ain't broke, you shouldn't fix it.
I'm just a kickin' and a gougin' in the mud and the blood and the beer.