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I have the Ultra 4C Preamp that came with an external tube rectified power supply. Unfortunately, I don't think that he still offers the tube rectification anymore. Regardless, it is a great sounding preamp and he offers customizing. For mine, I ordered the Auricap option and a mono/stereo switch.
Doug Sachs preamps include PCB’s, so it is not strictly a point-to-point wiring job. Also a quote from his custom line stage landing page regarding his finest preamp: “I cannot do XLR outputs, so please don’t ask. Also, I no longer wish to build preamps with HT switches, so please don’t ask for that either.”
But the Sachs line stage appears to check all of your other boxes. It’s got great aesthetics, and many attest to it having great sound quality.
Not many tube preamps can drive headphones directly. Headphones typically have a 32 ohm impedance- that's a bit of a problem for tubes. Its a pretty short list as far as I know; our MP-1 preamp and the microzotl headphone amplifier are the only ones that come to mind. The latter can be used as a preamp. It is based on the 6SN7 and gets excellent comments.
OP: you might consider this one, too, from Supratek Audio: New Generation 3 Chardonnay Line stage. 6SN7 preamp tubes, 5AR4 tube rectifier, 6L6G/5881 tube shunt regulators. XLR in/out. 4 RCA in/3 RCA out , remote volume.
It appears to check off all your boxes. I am not sure the XLR ins/outs are true differential balanced connections (likely not), but you did not specify that requirement in any event.
There are several Supratek products available on the Market Site. They appear to be shipping from Western Australia.
Ralph, do you mean if it has tube regulated voltage, e.g., using OD3/VR150 type tubes, etc., or something else? How can one visually tell if a point to point wired preamp has regulated power supply? Thanks.Whether it is tube regulated or not should not make a difference. An effective regulator will not allow of the sawtooth waveform generated by a rectification to pass to the output. BTW, 0D3s and the like are voltage reference tubes, sort of the vacuum tube equivalent of a zener diode. They are known to make noise and so must be adequately bypassed, and generally are not of much use unless also used with an active regulator circuit, which if in a tube embodiment will have some sort of power tube involved.
It can be hard to tell if the high voltage is regulated but if there are no power devices like a transistor or tube for the task its a pretty good bet that no regulation is employed.