Quote Originally Posted by Justaguyin_nc
I think I want to make this amp have more head room with a Clean tone instead of the break up. Allowing the pedals to do most of the over drive sound for me (thats why we get pedals right?). I am going to think about getting tubes of less gain addition. I have read some place if you swap to a 12AT7 over the stock tubes, you will have that cleaner sound, more head room with about a 40% drop in gain. This will probably be my first priority.
If you're looking for more headroom, Justa, then you're better off focusing more on the power tube than the preamp. Lowering the gain on the preamp tube mostly just drops the signal amplitude sent to power stage. The effect I've noticed is that it drops the apparent output volume, so that you'll need to turn the volume knob up further to get the same volume that you had with a 12AX7. But once you do, you'll get pretty much the same amount of breakup you got before, because the power tube is working just as hard, and it saturates before the preamp tube does.

What I'd recommend is to order a J&J EL84 from Bob Pletka at Eurotubes.com, specifying that it's for a Valve Junior and that you want max. headroom. He'll send you a power tube that has been specifically selected for minimal breakup. You might also want to get a 12AT7 while you're at it, so you can fool around with various tube combos and see what gives you the best result. As I recall, the J&J tubes use the European tube nomenclature, so you'd want the ECC81 preamp tube. Another preamp type you may want to check out is the ECC832. This is a 12DW7 type, a hybrid tube that's like half a 12AX7 and half a 12AU7 (which has a gain of only 20), with a gain factor very close to the 12AT7.