Tube preamp With 2 single ended outputs.

The new Cary SLP2002 has single ended and balanced double outputs , one labled HT bypass.

The VTL 2.5 or 5.5 has what you need. I just sold my 2.5 a few minutes ago if you wish to see my add for future purposes.

It is a great option and even comes with a remote!

Happy listening,

Jimmy

My Air Tight ATC-1 has two identical single ended outputs and sounds great.

I am connecting the 2 pairs of XLR output of a BAT VK-50SE to a Theta Dreadnaught to biamp a pair of Martin Logan SL3. You can also use a XLR to RCA adapter with it. You don't have to limit youself with only SE preamp. The VK-50SE does not have a HT bypass but it can preset any input to fixed unity gain. That is what I use to connect a processor's two front channels.

All the Line series preamps from Sonic Frontiers (Line 1,2,3 and the SE versions) have 2 single ended and 2 balanced outs along with a HT passthrough. Wally

My Cary SLP-50B has 2 single-ended inputs and a ht bypass which was really a third input modded by Cary.

CAT has two s-ended outputs -- but no ht bypass. It also sounds very good. Maybe CAT can wire in a by-pass.
I'm sure there are many other offerings... Cheers!