So, as per my previous post, I placed an order for the little dot I+ via e-bay on 15/08 and began the patient wait to receive my first (hybrid) tube amplifier. I received a useful e-mail from David that evening setting my expectations RE delivery etc. David said to wait 3-6 business days for processing and a tracking number. Sure enough, on 22/08, I received another e-mail with my shipping ref. Then, to my surprise, my amplifier arrived the next day!
To give you a bit of context, my previous setup consisted of the uDAC > Sennheiser HD 25-II. Now the I+ sits between them and I'm using the uDAC purely as a DAC (oh and I brought some £3 OFC shielded RCA interconnects off ebay). See my sig/profile for more detail RE my setup.
I think I've got around 8 hours of listening on the amp so far. The change in sound by introducing the LD I+ into the mix - instead of using the uDAC headphone out - is subtle. I've noticed a tinge greater warmth, smoothness and space. Treble harshness (experienced previously when listening to Joni Mitchell's Blue, for example) has been tamed. Those are really the only observations I feel confident making at this stage. I suspect I may have lost a hair of detail, this is especially apparent during the first half-hour or so of listening, while the amp warms up.
The consensus RE the uDAC appears to be that the headphone amp section is on the warm side, and given the LD I+ isn't a true tube amplifier as I understand it - incorporating a SS element, may account for the subtly of change. That, and the fact it doesn't have many hours on it, and I'm running the stock tubes.
Once warmed up I can hear a humming noise (though not with headphones on) emanating from the amp. With the uDac's volume knob set at 3 O'clock, 9 O'clock on the LD I+ is too loud, but there is plenty of room for adjustment in this range. Cranking the LD I+ volume all the way up reveals no hiss whatsoever to my ears.
I wasn't expecting to be blown away by the LD I+ - especially given it's price and hybrid design (I'm not saying hybrid amps are inherently bad, I just didn't expect it to be worlds apart from other SS amps, vs. pure tube perhaps), and I'm not at this point in time. I'm certainly happy enough with it to keep it in the chain and I look forward to any improvements resulting from further burn-in. I will also be experimenting with better tubes and opamps of course; I've just started working my way though the LD I+ tube rolling thread. I'll post any further changes I observe.
A couple of pics of the LD I+ in situ:
Throw in some LT1364CN8 OPA and be amazed, the stock one is just crap. Also, replace those stock tubes with WE408A.