Who makes this Pre-amp?

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. 

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.

www.supratek.com.au

04-04-2019 10:59am, I wrote: “Doug Sachs preamps include PCB’s..”

I meant to write: “DON Sachs preamps include PCB’s..” (emphasis added) 

I hate getting names wrong, so I apologize to Don for having done so here.