I have been kicking around getting another head for ahwile. I was an inch away from picking up a Walter Woods head when I saw the light.... I stopped in at the local GC yesterday to see what they had. I haven't played through an Ampeg since I'd sold my 70's SVT around '82. Well, I plugged into a SVT Pro 4 head and was amazed at the tone, variety of sound and incredible volume! I a/b'ed it with a SVT Classic as was amazed how "tube-like" the Pro 4 sounds. In fact, there was little (if no) difference in "tube warmth" and the Pro 4 seemed to have a little more kick. I understand there are 3 tubes in the preamp section, so that explains the sound. You've gotta love a 5-year wattanty also! Anyway - I am the newest convert to the Ampeg cult! Now if I can just find someone to buy by Trace RAH600SMX!