Sounds sweet! Lot's of low end rumble. Sounds great with my B4r and sounds even better with my SVT 200T. I guess I just like that Ampeg old school sound. My guitar player has an early 70's SVT that he is going to let me use now and then. He has to convert the output jack to 1/4inch somehow first. can't wait to here how that sounds with the 610. Got three gigs this weekend. Can't wait!