using two outputs from a dac?

When I purchased my Denafrips Pontus II DAC, I was informed by Alvin at Vinshine Audio that using both the XLR and RCA outputs simultaneously would result in a degradation of performance for the DAC. I also wanted to connect my DAC to both my integrated amp and headphone amp. Alvin then sent me a design for a custom cable that would solve this problem. The cable connected to the XLR outputs from the DAC and split off into two separate RCA connections to each of the amplifiers. I sent this design to Morrow Audio and they built the cable for me which has performed flawlessly. The only downside is having to use RCA instead of XLR to my integrated amp which I use way more than my headphone amp.

Thank you both so much. @erik_squires--that's reassuring, at least in the sense that I'm not going to fry (or blow up!) anything. @mksun, very bright and pretty cool to have such a bespoke cable. If this setup becomes permanent, I'll consider one for myself.

Usually all output are live unless your piece of equipment has output selector switch. 

It’s best to contact Bryson for their recommendation. It all depends on the output stage design. Some manufacture design separate output circuitry for single end and balanced output. Henceforth both can be used simultaneously. Other simply tap the positive leg on the balance output and therefore doesn’t recommend using both together.

just my 2 cents.

Provided that you don't have a turntable, if your DAC has an analogue volume control, as does Audio Analogue's DAC, you don't need a preamp.