Now that my Music Hall tube dac mods (DynamiCaps, Burson op-amps, output stage mods) are done & it's back in my system feeding my Sonos ZP90 I've starting counting the breakin hrs. I'm using the EAT ECC-88 gold pin tube now & I also have a Bugle Boy to swap out when the mood strikes me. I'm at about 30 right now & it's really starting to open up & impart a nice sweetness to the music. I won't pass final judgement till it has a good 200hrs though. If it sounds this good after only about 30hrs I can't wait to hear how it sounds once the hrs have racked up.
The bass has me scratching my head on how it's tighter, forceful, & more dynamic without being overdone. The vocals are coming thru more front & center with a nice crispness & a lush sweetness. Very natural & easy on the ears is a nice way to describe it. The imaging is maybe about the same but I expect to hear changes as time goes on. The soundstage has widened & moved forward a bit but also this will probably improve over time also. But for right now I'm really enjoying my new sound!!!
This is one fine stock dac & new mods have really taken it to a whole new level.