pre amp tube q's

[brit84]

what tubes are good for metal, thrash high gain tones?
My genz is supposed to have a tesla 12ax7cz in input and two ruby 12ax7ac4 in the other positions. Problem is the tubes in the amp have no markings so i dont know if the guy i got it from changed them. Should I stick with the original set?

How do you tell if tubes are old?

thanks guys

 

[Gearjoneser]

Re: pre amp tube q's

There's a few guys on Ebay selling Shuguang 9th Generation 12AX7's pretty cheap in unlabeled boxes. That's what you should get. GT12AX7C's are the same thing, and they're the tightest and hottest tubes for channel switching highgain amps. Great tubes! For regular everyday players, power tubes should be changed about 1-2 years. Pre tubes should be changed about every 3 or 4 years. That's for everyday players on the same amp. If you don't run your amp that often, your tubes will usually last 5-10 years.

I'm a real fan of Chinese Shuguang 9th Gen pre tubes and JJ power tubes. That combination in any amp will usually out-do the current tubes.

 

[brit84]

Re: pre amp tube q's

thanks