hey hey, santacore, glad to see you chimed in! Sounds like ser nr #0001 has a lot of the same characteristics as ser nr #0002. Gawlly!
I've been letting mine run in, with occasional cooling down periods to let the caps and all breathe. Some say 2 hrs on, 1 hr off, but since I know Donald's set us low on the transfer graph, I'm running more like 6 on, 2 off.
With > 60 hrs now, it seems like it has already settled down quite a bit. The detail is coming through more clearly and that slight orange glow (which santacore pegged right as a small band with a little umph in the upper mids) seems to have faded out. Through the LA7000 headphone, I hear a bit of extra bass, but it's not bloom, as it has excellent timbre and dynamic control - it's part of the signature of the D7000. In fact, the attack, tone and fade of the timpani and plucked double bass are the best I've heard.
So I got antsy. It has full-bodied sound, and excellent extension on both ends, with dynamic contrasts galore, but the timbral palette seems a bit shy and the clarity dial definitely needs a turn. So out came the NOS 5U4G cryo'd Mullard that I purchased back in December, when I submitted my pre-order with Donald.
Donald did us a huge favor selecting this rectifier. It is one of the full-wave rectifiers with a top-notch reputation, but there are enough of them floating around still so that they don't cost a fortune. I paid $89 for one of the very best, but you can still buy a 1970s NOS tube for $29, and 1960s better for $39.
And WOW, did it make a difference! Gone were the fuzzies at congested parts - black went the background between notes, air appeared between voices, and the timbral quality of every voice added another couple sub-harmonics. In other words, the sound got better, way better.
In fact, I sat back and listened to the entire CD, and that was my evening.
So next test will be 2 or 3 other headphones.