You can replace the tubes yourself.
On the preamp tubes, they impact all channels.
For what you want use an SAG-MHG kit for V1, V2, and the phase inverter.
For output tubes use the 6L6S in a 5-6 rating and if the amp has the stock bias these will be plug and play. If you order off the GT website put in a comment asking for a 5-6 rating only. Kool, Thanks alot. For the power tubes does the brand make a big difference? You can get the 6L6S from many places but it is a specific type of 6L6 (JJ) but if you want to get a 5-6 rating, only GT has these ratings from dynamic rather than static matching. If the tubes come from another source you will need to check the bias and probably have it adjusted. Sorry for the many questions, but what is a good price range I should be paying on the power and preamp tubes, I don't want to be paying too much for them when I decide to purchase them.
Also regarding the pre-amp tubes, the kit is only 3 preamp tubes, but the amp holds 5 preamp tubes, so what do I use to fill up the other 2 spots?
Thanks Alot