Tube pre amp with 2 outputs for Biamping

Let me posit a conjecture: I believe that there could be a difference between using an external "Y" adapter vs. going with an internal two-output design in the possibly reduced input impedance seen by the parallel-connected single output in the latter case. In this scenario, hooking up two amps through a "Y" apdapter could increase distortion, reduce headroom, and compromise frequency response with a preamp whose output wasn't designed for it, whereas an appropriately designed dual-output preamp wouldn't suffer in driving two amplifiers. But I don't don't have the expertise to know this for certain; it would be better if someone more knowledgeable than myself could post after me confirming or refuting this.

There is no difference between splitting the signal inside or splitting it outside. And splitting an output does no harm to an audio signal. If you are concerned that the wire is different than whats in the preamp then your interconnects should be the same as the wire inside the preamp. If you can get interconnects like the wire inside your preamp then you can get Y cables like the wire inside your preamp. Or, you can do like I did and add your own parallel outputs yourself. Or get a preamp that has single ended and balanced outs and use a single ended adapter on the balanced out. By the way, you should not split a composite video signal.

The conrad johnson pv10a does not have dual output jacks.

The Blue Circle BC3/BC3000 has two outputs. Blue Circle really makes a special preamp. Have to second the Air Tight and Jadis recommendations as well(didn't know they had 2 outputs).

Actually, it may only be the older JP80s (like mine) that have the two outputs, as the website talks of only one output and four line level inputs (mine has 2 and 3). Not at all sure about my old JPL anymore; I do seem to recall my old ARC SP11 having two outputs, any owners out there who could verify that?