I was fully expecting to have to troubleshoot, but all my resistance and voltage checks were perfect at the end, and everything sounds great! Moreplay is my first tube device, so I'm thrilled to explore my music library all over again.
I've got low impedance planars headphones, so I decided to go with a tube pre-amp instead of a full amp. That way my solid state amp can handle the high impedance output without having to worry about frequency roll off, but I can still get some of the tube sound to pass through. And so far, I'm loving the flavor it adds to classic rock and grunge. Alice in Chains has never sounded this good on my headphones! It definitely makes the the guitar riffs smoother and richer.
Right now I've got it set up where I can flip a switch on my Amp to switch between sound direct from the DAC or through the Moreplay (volume matched). This makes it easy to turn off for the songs where I want that crisper detail.
But honestly, I'm totally blown away how clean this sounds! I was expecting it to make my music less detailed or significantly distorted, but everything is so transparent. It's hard to believe that the handful of resistors, capacitors, and diodes I soldered together can keep up with the rest of my system.