I have a Marshall 4145 4x10 JMP Combo amp... i am the new owner of it and it needs new tubes. i read up on it drtube.com and it's supposed to have 4x 6550 and 5x ECC83 but i need to know what is the huge difference between 6550 Tubes and KT88's and what brand to get???
www.thetubestore.com has reviews of different tubes and brands, reasonable prices too. If you want to talk to someone who probably knows your amp, email the guy at www.eurotubes.com , Bob. He will usually take the time to explain some stuff to you by email and give you a good idea about the differences. The drawback is he only carries JJ tubes, but they are good tubes IME.