Peavey 5150 & 5150 II?

5150 II Features :

120 Watts RMS at 16, 8 or 4 Ohms voiced to Edward Van Halen's specifications and identical to the amps used by him when touring and recording
Six 12AX7 preamp and four 6L6 power amp tubes
Footswitchable lead/rhythm channel select and effects loop
3-band EQ, resonance and presence controls on each channel
Rhythm channel: pre-/post-gain controls
Bright/crunch switches
Lead channel: pre-/post-gain controls


5150 Features :

120 Watts RMS into 16, 8 or 4 Ohms
Five 12AX7 preamp tubes
Four 6L6GC power amp tubes
High and low gain inputs
2 channel preamp switchable on front panel or remote footswitch
Rhythm channel: pre- and post-gain, bright & crunch switches
Lead channel: pre- and post-gain
Channels share 3-band EQ, presence, and resonance controls
Switchable post-EQ effects loop

5150 II has a better sounding clean channel but the gain sounds different from the original. aLot of people
mod the lead channel circuitry to get back to the original lead channel .

http://fjamods.com/5150II.html
 
I like the Original better as well. I retubed mine with JJ's and put 2 lower gain pre amp tubes in the V3,V4 slots and my clean channel sounds real good now. It also helps kill the hiss that you get from the lead channel.
The original to me sounds much "fatter" the the II does