Need a Lonestar Special preamp tube in V3

[Gunner]

My FX loop quit working so I pulled the V3 tube and the bottle was broken. I put an old 12
AX7 in there and it works again but the tube is old and I want to replace it. The old tube says: Mesa 7025 STR 12AX7-A ECC83. On the Mesa site they have an SPAX7-A for $21 and a 12AX7 for $17. Would the STR be the direct replacement?

Another question: I had power tube go bad under warranty and Mesa quickly sent me a box of two power tubes. Should I install both these tubes because they are matched or something? I told them the original tubes were the yellow tags so they sent me yellow tags. If I should install them both, what positions should I put them in?

Thanks!

 

[212Mavguy]

Hi,

Although the more expensive spax7 seems to be the match, due to Mesa sometimes over the course of their history changing preamp tube suppliers it might not be exactly the same guts inside the bottle even though the printing on the outside matches...

I think that if you went ahead and got that spax7 you'd be ok, and maybe after the warranty expires (if that is important to you) you might get some better quality vintage tubes for your amp. Or simply get the vintage tubes and keep the stock ones to stick back in if there ever needs to be warranty work done.

Check out the posts by Stokes, Timbre Wolf, Shredd6, others, and possibly myself on VOS and NOS tubes in LSS amps. You should find some good ones within the first three pages of topics. Some have found these older posts to be illuminating. :wink:

As far as those power tubes go, look in your owners manual for the power tube assignments, those matched replacement tubes were meant to be installed together as a pair. I'm not sure off the top of my head whether those power tube pairs have an xyyx or xxyy type of arrangement. Peace.

 

[KH Guitar Freak]

Just put the SPAX7 in V1, and use your current V1 valve, and slot it into V3... 8)