Sorry for staying off the topic, but there seem to be a lot of people here who had experience with TOTL headphone amps, so I'll ask. I use Fostex TH900 as my primary reference headphone, and I wonder which of these headphone amps will be the best match for it. For me, Eddie Current Zana Deux SE is as far as I could spend, which cost me up to $3400 including upgraded components such as Mullard ECC35 driver tube ($300), Penny & Giles potentiometer ($300), Stefan AudioArt Endorphin umbilical power IC for ZDSE ($475), and Audio Magic Super Fuse ($100) altogether. While I've done practically everything to make my ZDSE the best-sounding ZDSE possible (and stock ZDSE is still considered one of the best amps to drive the TH900), I'm curious about how TH900 would fare with even more upscale amps that are out of my reach, such as the Pinnacle, Balancing Act, Liquid Glass, etc. I know the TH900 is a relatively easy headphone to drive in terms of power sensitivity/efficiency, but merely having enough power doesn't always mean sounding exceptional.