trouble shooting

[angelodp]

Electro Harmonix 12AX7 / ECC83 pre-amp tubes
NOS Soviet 5U3C / 5U4 / 5U4GB Winged "C" Rectifier Tube
4) Match'd Russian 6pi14pi/EL84/6BQ5 tubes,NEW!

Ok here is the scenario. Rocket works great with older 12ax7's and newly purchased rectifier tube and quad saratov el=84's

Pulled the old 12ax7's and installed the newer EH 12ax7's turned on the amp and wham... lost my amp fues and the rectifier was blown as well.

Ok... pulled the EH 12ax7's and rect tube and put in older 12ax7's and an older rectifier tube and a fuse and back to life... all is well.

Theory - the newer preamp tubes were too much for the older russian rectifier tube to handle???

or what .... amp is working again

[castor]

when im my hifi tube amp the current out of my rectifier tube was not enought I had some scratch.. some lights and flash on the recto tube and after that the fuse blew down.. but not immediately

castor

[rooster]

I'll be Spock here: No, its not logical.

So you have a 12AX7 that has something shorted within its connections. Try one at a time. Stuff happens with these new tubes sometimes...

[UR12]

Electro Harmonix 12AX7 / ECC83 pre-amp tubes
NOS Soviet 5U3C / 5U4 / 5U4GB Winged "C" Rectifier Tube
4) Match'd Russian 6pi14pi/EL84/6BQ5 tubes,NEW!

Ok here is the scenario. Rocket works great with older 12ax7's and newly purchased rectifier tube and quad saratov el=84's

Pulled the old 12ax7's and installed the newer EH 12ax7's turned on the amp and wham... lost my amp fues and the rectifier was blown as well.

Ok... pulled the EH 12ax7's and rect tube and put in older 12ax7's and an older rectifier tube and a fuse and back to life... all is well.

Theory - the newer preamp tubes were too much for the older russian rectifier tube to handle???

or what .... amp is working again

I have had two brand new sovtek 5ar4/gz34 rectifier tubes blow out in my rocket, one as soon as I put it in and another when I cranked on the amp. The Sovtek rectos are junk IMHO and you are much better off with a JJ or new old stock. I am betting your 12AX7s are fine and it is just those junky Sovtek rectos that are your problem

[angelodp]

You are correct sir..... the old russian recto... just failed, I can see the little wire that broke free in there. Put in an RCA recto and all is well again in Rocket heaven.

a

[tubedogsmith]

It's really funny how peoples experience differs on some of this stuff. I bought 5 dozen Sovtek 5ar4's 8 years ago and never experienced a failure. I've bought probably a couple dozen since then although not in at least a year and a half and never expereinced a failure with any of those either. Two years ago I bought 6 JJ 5ar4's to try based on internet chatter and the first two blew up and blew a fuse as soon as I hit the switch. I gave the other 4 away. Pretty much similar with the JJ el84's. I'm not disagreeing just pointing out a different experience. I'd guess the tube runs these guys make must be all over the map regarding quality control.

[angelodp]

Yes indeed. I just put a GZ34 in there and whoaaa!! The amp just took on a whole new timbre. Volume went up and it's more brash in a way although I can dial that back on the tone controls ). Generally the GZ34 seems to be tighter louder and more aggressive.

a

[geetarpicker]

Ken Fischer mentioned to me quite a few times that the ONLY rectifier tube he would put in a Rocket was an original Mullard GZ34.

[Lonely Raven]

Ken Fischer mentioned to me quite a few times that the ONLY rectifier tube he would put in a Rocket was an original Mullard GZ34.

Which I see are now going for $150 to $200 NOS.