If still of interest, I owned the WA8 a while back and have recently managed to get my hands on the CDM. Here are some very unscientific thoughts on the two: the WA8 was an utterly impulsive pandemic purchase, and i absolutely loved the sound quality, esp. on 3 tube configuration with full sized cans, but also two tube with iems. Incredible warmth, gorgeous natural soundstage, utterly addictive listening and worked with everything I plugged into it (although the synergy was better of course with some cans than others.) It was also a gorgeous object to look at and built like a tank. Everything else I thought was a bit meh - it weighs a ton, it's battery was poor and it was an absolute pain to lug about, especially with the (virtually essential) charger. It also felt weirdly fragile, and a looming drama to need to send it back to the US (from Europe in my case) for new batteries and/or tubes. All in all I know it was marketed as somewhat portable, but I found it barely even transportable given its weight. More of a small desktop setup with a battery for added flexibility. I therefore used it far less than the stunning SQ deserved, and when money got tight I was sad, but not that sad, to let it go.
I've just been incredibly lucky to pick up a CDM from another headfier for a price I feel profoundly grateful for - overall it's proved to be everything I had hoped from the WA8. In terms of sq, admittedly with the mullard tubes installed, it gives up very little (from memory) to the woo audio product - it's a little more linear, a little less "tubey" so perhaps a fraction less characterful, but the staging and imaging are sublime and without the WA8 here to compare directly, I have the same silly grin on my face when I listen to both devices. Form factor and battery life are simply way better for the CDM. You truly can take it round the house with you or venture outside, and you don't watch with anxiety as the battery drains over the space of a couple of albums, it basically goes all day. And you can tube roll, and the batteries are user replaceable, and it's (relatively) light and it looks just as beautiful as the WA8. I know they're different amps, one is pure tube, the other is hybrid and in fairness I have only used the CDM as an amp thus far. I really did love the SQ of the WA8, but if I had to pick one to keep, money no object, I'd still go CDM. It just makes more sense as a product to me. Hope this of some use to someone!
