Let's step aside for a moment and look at amplifier topologies. The Dawn is a derivative of the Don Sachs DS2, which a version of the Aikido preamp, which in turn is an SRPP followed by a cathode-follower with a vacuum tube current source as a load. All four tube sections are the same type and run at the same current.
SRPP's are quasi-balanced, with the upper tube canceling some of the nonlinearities of the lower tube. I think of it as a series balance, unlike the parallel balance of the Raven and Blackbird amplifiers. The difference? In a series circuit, if you pull one tube, the whole thing goes dark, like old-fashioned Christmas-tree lights. In a parallel circuit, it still keeps working, just not as well.
The Dawn is not a classical single-ended circuit like a Marantz 7C or Audio Research SP6. It's an SRPP, a form of quasi-balanced circuit, with partial cancellation of tube distortion thanks to the inverse action of the upper tube. SRPP's have their own personality, with the biggest drawback being substantial changes in distortion spectra with load. The Dawn/DS2/Aikido sidestep this by having a tube buffer following the SRPP section. A clever feature of the tube buffer is using the same type of tube for the current pull-down, so all four tube sections are the same type, hopefully cancelling some (perhaps most) of the nonlinearities of the tube type.
Spectrally, each topology has its own character. Classical single-ended, with resistors as plate loads, has a lot of 2nd harmonic, and a fairly rapid drop above that, depending on selection of tube type. Fully balanced, as in the Raven and Blackbird, has an equally rapid drop-off of upper harmonics, with about 30 dB of cancellation of the even harmonics. SRPPs basically fall in-between, and some have a slower harmonic dropoff, depending on tube type. A series-balance circuit does not have the same spectral character as a parallel-balance circuit.
This larger point applies to power amps as well. Conventional PP tube amps all have vacuum tube phase splitters, and these phase splitters are not sonically neutral. I'd go out on a limb and say the choice of phase splitter actually dominates the sound of most PP amps. The Dynaco circuit uses a "concertina" or split-load inverter, while the Mullard (most common type today) uses a differential stage. The Raven and Blackbird have fully passive phase splitting via transformer coupling. Each type has its own sound, partly because the distortion of vacuum tube phase splitter is not internally cancelled via circuit balance.
I've been working on tube amps since the mid-Nineties, and Don has another decade on me, or even longer. We know the sound of each type. They are quite distinct from each other once you've built a few. The Dynaco has its own sound, and the Mullards have a house sound as well. The SRPP's have their own sound as well ... an unbuffered SRPP has a certain sound, and putting in a buffer changes it again.
