I have abt 15 hours of play time on the acme 300bs. My observation is that the tube sounded its best in the first 10 hours of playback. It went downhill after that. Its still great sounding no doubt but seemed to have lost some of its magic that awed me right at the start.
That level incisiveness to the music which had captivated me seemed to have toned down a little. Especially on the track Spanish harlem by Rebecca pigeon, the bass lines seem to have lost some palpability and the part where the shaker comes in, seems to have lost tht bit of incisiveness. What was retained however, during the last 15 hours was how the music was portrayed in a very nicely layered 3d space with good amount of depth.
Does anyone here share similar experiences with tube break-in? Are the perceived changes in sound a matter of tubes breaking in or is it more a psychological one, where our ears get accustomed to the initial excitement.
My dealer says that it takes ard 50 hrs to "settle in". Keeping my fingers crossed that the magic will be restored fully once again.
As tube get burned in, its sound can get gentle and more refined but may give impression of losing some incisive bass.
I had used combination of Acme 805 and 300B for 150 hours.
My impression so far is its sound is on the refined side, while NOS WE 300B sound more incisive with tighter bass.
But it is hard to find good NOS WE 300B and they are expensive( 5000$ or more for pair).
If Acme works fine for more than 2000 hours , then it will be very good for the money.
So far my impression of Acme series is very positive with musical sound.
I think it it the best new production Vacuum tube that I had experienced.
For reference I had lot listened to Erlog 300B yet.
1998 WE New production 300B was disappointing and it will be interesting how 2019 WE 300B New production will turn out.