volume lose with dual rec

[interrogate]

hey there, today i put a new set of preamp tubes in my dual rec, took my amp to practice, turned it on let it warm up for a few mins took it of standby and it had lost bout half of its volume! I`ve never had this problem before and hope it is`nt anything serious, after a few mins the volume increased back to normal then decreased again at the end of practice for about 1 minute then shot back up again? Dose anyone have any idea what mite be the cause of this? Could it be a faulty preamp tube? thanks for any help with this in advance!

 

[primal]

Judging by the fact that it never happened till you replaced your preamp tubes, I would have to believe that it is related.

Also, some of the rectifiers have an issue with the cathode follower tubes causing volume drops. It has to do with the chineese or russian preamp tubes. One tends to fail with low line voltage, the other doesn't.

Search this forum for Cathode follower and you should find some info on it. It sounds a lot like the issue you are having.

All else fails, as long as you still have the old tubes throw those bad boys back in and see if the problem goes away.

 

[interrogate]

Thanks very much for the reply and help, as soon as i get a chance i will pop in my old tubes to see what happens, the tubes that i purchased were Russian 12AX7 electro harmonix pre amp tubes so i guess there`s somthing with them that is`nt agreeing with my head. I`ve been running groove tubes in both my heads and never had any problems like that before so maybe i should just stick with them to be safe :roll:

 

[lerxst88]

did you happen to touch the power tubes?

doublecheck to make sure all the tubes are firmly seated. sometimes the simplest solution is the correct one

 

[interrogate]

Hey, yeah i checked all tubes twice over and they all seem to be seated fine, tryed amp once more there and it was quiet again, took the new preamp tubes out, poped the old ones back in and everything was fine so i guess the tubes i bought just don`t agree with my amp, think i`ll just stick with the groove tubes to be safe.

 

[lerxst88]

maybe the tubes you had were higher gain than the new ones?

did you happen to use 12au7's? just a thought