Let's Talk Tubes.........

I am about to replace the tubes in my Mesa Rect-O-Verb, and am wondering what I should get brandwise, etc? I have never bought tubes before because the ones I got with the amp when I bought it used have lasted me til now. Any ideas? Also, does anyone have an estimation of how much it will cost me to get a brand new set of tubes? Anyone who owns a Mesa Single Rectifier please chime in. Thanks.

Also, how easy is it to install them? I'm wondering if I could do it myself and save some cash or if I should hire someone to do it for me.

Check out Groove Tubes on the web. Lots of good info there.

You can easliy replace tubes yourself if you can do anything more complicated than change a light blub. BUT...read on.

Groove tubes has a cool new pre-amp tube that recreates a popular tube Mullard made way back when. I think it's the 12ax7M...with the quot;Mquot; standing for Mullard. I put three in my Carvin X-100B (fozzy bear series circa 1993) and was amazed at how much better the amp responded to picking dynamics. The tube is a bit on the expensive side (~25$ US) but since pre-amp tubes tend to last a long time... (90% of guitar pre-amp tubes will be some variety of the 12ax7 family.)

Now power amp tubes (the big ones usually 6L6 or EL34) . You can change them yourself but beware that your amp will most likely need to be re-biased to achieve the best results. I'm not too much of a tech but you can think of the amp bias as being akin to setting the idle on your car. Too high and it's hard on the engine and wastes gas...too low and the engine stalls. So find a tech who knows what he or she is doing or you could damage the amp at worst, lessen the tube life at best. Power tubes should be matched for best performance since most guitar amp use a quot;push-pullquot; configuration where one tube amplifies the positive portion of the wave and another amplifies the negative portion. (Assuming a 2 tube power stage for a 4 tube power stage it's the same only 2 tubes do the positive and 2 tubes do the negative)

The cool thing about Groove Tubes is that they are very well matched and rated. If you get your amp set up to use a certain tube at a certain hardness (they rate 'em from 1-10....1's distort the easiest 10's the hardest) you don't need to re-bias every time you change power tubes. Just buy a matching duet or quartet at the right hardness # and you're good to go. (Oh yeah...you don't have to worry about bias for the pre-amp tubes...just replace them with the same model.)

As far as price...depends on how many tubes your amp need. But 150-250 $ is a good estimate.

The Rectoverb is fixed bias, and rather cold at that, so as long as you go with the same type of tube in it now (6L6 or EL34) you shouldn't have any problem going plug 'n play. I use JJ/Tesla power tubes (from Eurotubes) with Shuguang 9th gen Chinese preamp tubes in V1-3. I have a JJ ECC83S in V4 and the phase inverter spot, and I think I'm about to try one of those GT Mullard reissues in V1, but right now I'm very happy with the tone I get from my Rectoverb.

For that amp, I'd recommend ordering from and getting
JJ 6L6's and GT12AX7C's. The power tubes will make your amp sound better than it did new, and don't go cheap on the pre tubes....instead of changing all the pre tubes with $8 12AX7's, just buy 2 GT12AX7C, and put them in the first two positions on your amp. They're worth $14 each because they'll tighten up your whole pre section and your gain will sound smoother and less harsh.

Would you recommend the 12AX7C over the 12AX7M in that amp GJ?