Tube Question

[bronco]

Does anyone know if any other tube would work in place if a Sovtek 7199 in my Sunn amp? Also would a 12ax7 or a 12at7 work in the place of a 12au7?

Any help would be appreciated.

[Ryan Phelps]

: Does anyone know if any other tube would work in place if a Sovtek 7199 in my Sunn amp? Also would a 12ax7 or a 12at7 work in the place of a 12au7?

: Any help would be appreciated.

According to my RCA Tube Manual (RC-29) there is no replacement for the 7199, a medium-mu triode/sharp cut-off pentode. The Sovtek is a well-priced tube of curent production. NOS versions will run $25 each or more. The 12AX7 and 12AT7 (and 12AY7) are all from the same "family" and can be substituted in guitar amps for the 12AU7 without damage, however the performance will change. The basic difference is the amplification factor. A 12AX7 has an amplification factor of 100, 12AT7 = 60, 12AY7 = 40 and 12AU7 = 17. So if you substitute the 12AU7 with one of these, you will likely overload the following stage, causing un-wanted distortion.

Good Luck!
Ryan

[bronco]

Thanks Ryan.  That totally answers my question.  This site rules, no one makes you feel like a loser cause you may not know as much tube amps as others, or not have a electronic diploma.  I'm just a guy who plays in a band and wants to learn how to service his own amps and save not only me but friends a few bucks.  The only company that services tube stuff here absolutely rapes the musician, totally not cool!

Thanks a bunch!