Contemplating a new headphone amp. I have decided on the company, now I need to decide on the amp. Woo Audio is a US company that specializes in headphone amps. I have it narrowed down to the WA3 or the WA6 I need a little advice. WA3 WA6 The WA3 goes for $600, the WA6 for $700. I don't need preamp outs and I will not buy their upgraded tubes. I have my research down on the tubes and rectifiers for each amp. The WA3 is a OLT design, or an output transformerless design. This has a tendency to be extremely linear. But it has the drawback of needing really high impedance drivers to provide beneficial damping factor for the transformerless output design. Basically, it is supposed to be one of the nicest amps to pair with the Senn HD600, 650, 700, 800, etc. Plus it is $100 cheaper than the WA6, which means for the same money I can roll more tubes. BUT!!! Low impedance drivers do not offer the damping factor required to make the OTL design work to it's potential. I have a few "bucket list" cans I want, and some do not fall into the high impedance driver category necessary to facilitate the WA3. The WA6 ticks all the boxes for the HD600s, and my "bucket list" cans. Not only that, but my Momentums will fall into the "wrong amp, fucktard" scenario if I grab the WA3. I was thinking about giving my son my current amp, and I really don't want a crowd of headphone amps on my nightstand. I also don't want to wind up with several DACs, and interconnects to further crowd my headphone amp area. Along with my nightstand I now have a rack with DACs, external HDDs, Battery backup, server, Pio Elite DV45A SACD/DVD/CD player, and 2 CD/DVD burners (I am a closet burner and have some really kick ass external burners). So do I buy the WA6 as a future proof deal, even though I may never buy another set of cans? Do I buy the WA3 as it is really THE design I want to go with my current HD600 cans, with the realization that I may be fucking myself in the future?