Rowland model 12's still reliable?

IMO the amp should work properly plugged directly into the wall. the manual states as much. As for using PS Audio, due to proprietary technology you should contact JRDFG before using a power-regeneration device. if you need confirmation of the modified units you can call JRDG with your two serial #'s.
BTW, i only had problems with one channel; the other one worked as new but both were sent back anyway. the amplifier units weren't touched since they
weren't affected. i even held onto them just in case i need a back-up unit.

French_fries was there any recall of units? How would you assure that unit has new PS design vs. old?

I'd be running it behind a Power Plant Premier. Do youthinkthat would make a difference?

the #12 had a (radical) new switch-mode power supply that worked great on paper but, at least in my case, didn't like voltage fluctuations or brown outs.
the power supplies were rebuilt by JRDG as a result and are now 100% reliable.
the amplifiers are beautiful both to look at and to listen to. i can't compare them to more recent offerings, but IMHO you're looking at the same form-factor as the new 725's with two boxes per channel. plus because each chassis only weighed about 32 pounds, one person could set up the amps themselves.
but admittedly Rowland took a hit with all of the peculiar things happening with those original power supplies. and the dealers were taking in $14,500 a set on them. well, that's the good, bad, and the ugly from my perspective.

Send it to Rowland for an inspection.