Today i happened upon a db 750 at G Guitars here in New Haven Ct - after playing it i had to run home and grab my rig to compare it both were played thru an aguilar 410 my rig is an alembic f1-x and sf-2 thru a stewart 2.1 power amp the units were compared in the usual a/b fashion, additionally i plugged the alembic into the poweramp in of the aguilar 750 as well as plugging an aguilar db 659 into the 750's poweramp in In a nutshell the 750 sounds fantastic -it sounded every bit as loud as my stewart (although i didnt go to speaker breaking levels). This was despite the aguilar being rated at about 450 watts into 8 ohms vs my stewart being bridged mono (1400 watts into 8 ohms). The stewart is rated at 400 watts or so into 8 ohms per side but it didnt compare when i ran one side by itself vs the aguilar. Tone wise i still prefer the alembic's clarity, the aguilar is definitely a bit "woolier" but can get a good level of clarity with treble and mid boost. At this level of construction it's more akin to what flavor ice cream you prefer rather than one or the other being "better" The 659 has 2 tubes, the 750 has 4 even though the interface is the same. one of the 750's tubes is apparently for the di out. Comparing the sound of the 750's preamp with the 659 was subtle, but the 750 definitely has the edge tone wise. Not being a rich man, i didnt buy the DB 750, (i would have had to trade my stuff in). but if i was a bit more affluent i wouldnt have been able to resist it. If i didnt already own my current rig the choice would have been a no brainer. The 750 sounds great, is as loud of an amp as you'll find, and at 46 lbs and 3 rack spaces it's not all that bulky. It sounds heavy, but trust me, you have to compare this head to full on rack setups which are right in that weight class, even if you use a stewart or plx. It's not even fair to compare the 750 to other heads - it's that good. FYI, no i don't work for aguilar or g guitars. The amp is that good.