I've had the opportunity to play through and record with a number of Dumbles over the years. There's a give/squishiness in their response that works for a number of well respected players. It's no secret that the early Boogies were fashioned after the brilliant HAD's work. It's no surprise to me that my favourite Boogie, which is totally slept on would bear a more than cursory resemblance (as regards feel and voicing) to HAD's amps. I have no doubt that there are several amp designers on this forum (who have a much better grasp of amp design) who will either negate or affirm my perspective based on the circuit. That being said, it's remarkable how similar this amp feels to me, regardless of the power tubes.