I ordered this sight-unseen based on my previous experience with the Mesa M-Pulse 600. I thought this would be somewhat similar to the M-Pulse, but with a simpler, more straightforward EQ. Well, the EQ is certainly more simple, but the tone is nothing like the very "tubey" M-Pulse. To my ears, it definitely leans toward the "solid-state with a little tube warmth" end of the spectrum. There is one 12AX7 in the preamp. The EQ is very responsive. You can use the bass/mid/treble controls only, or you can select one of the preset "voices." Positions 1 and 2 cut the midrange and positions 4 and 5 boost the midrange. The standard bass/mid/treble controls can also be used in conjunction with any of the selected voices. This amp is LOUD! It features 600W @ 4 or 2 ohms (yes, it will operate safely into a 2 ohm load) and 320W @ 8 ohms. Keep in mind, these are Mesa watts we're talking about here! 
The impedance is selected via a switch on the rear panel. The speakon output jacks also accept standard 1/4" plugs. This amp is extremely well-built (like all Mesas) and is in "like new" condition. I received it in mid-June. It has only left my house once for a rehearsal-never gigged. The current street price for these is $999. I'm asking for $750 shipped within CONUS only please. Remainder of Mesa's 5-year warranty is fully transferable. No trades please. For additional information, please go to the Mesa web site: http://mesaboogie.com/Product_Info/Bass_Amps/carbine/index.html
This is a great deal on what is essentially a brand new amp with most of the 5-year warranty remaining! Thanks for looking.
Cheers,
Kevin
The impedance is selected via a switch on the rear panel. The speakon output jacks also accept standard 1/4" plugs. This amp is extremely well-built (like all Mesas) and is in "like new" condition. I received it in mid-June. It has only left my house once for a rehearsal-never gigged. The current street price for these is $999. I'm asking for $750 shipped within CONUS only please. Remainder of Mesa's 5-year warranty is fully transferable. No trades please. For additional information, please go to the Mesa web site: http://mesaboogie.com/Product_Info/Bass_Amps/carbine/index.htmlThis is a great deal on what is essentially a brand new amp with most of the 5-year warranty remaining! Thanks for looking.
Cheers,
Kevin