@songmic FWIW I really love the pairing of the Pass Amp Camp Monoblocks with the older HFM headphones. The kit to build them is very inexpensive compared to other potential amp options, is upgradeable, and extremely easy to build. Good way to get into DIY and gain a better understanding of how amplifiers work too. It would be pretty easy to build something like an F5 or F6 as well. The specs don't match the sound whatsoever. The ACA has a better grip on the drivers of both my Code-LEX and HE-6 (currently with LFF) than anything I've heard up to date, including my Pass-designed Adcom GFA-555 (which is itself a completely underrated design, Luis uses one himself). I still have yet to hear other Pass designs or vintage amps, but I don't have any upgraditis in terms of amplifiers since building the ACA. I feel the ACA has a warmer textural rendering than many solid state amps as well, which pairs nicely with the older HFM's if you're normally sensitive to treble like me. Now I just feel my source and preamp could be better. DIY is always the best value, if you're willing to invest the time.