Newbie to the forum question. I got a good price on a Tung-Sol 12AX7 along with a matched pair of Electro-Harmonix 6V6GT tubes for my SCXD that's about 1 1/2 yrs old. Will this be a good fit for this amp? Any other recommendations out there? Only mod was an excellent sounding Weber 10S ceramic speaker that really has improved this amps over all sound. (it was good to begin with, now it rocks). I thought new tubes would benefit, as these are the stock China tubes in there now.