How to Bi-amp Pre-amp with only 1 set of XLR out

Can anyone tell me how to hook up 2 stereo amp with a Pre-amp that has 2 XLR output only? Can I just buy a XLR Y adapters If (there is such thing)? Does Y adapters degrade the sound? Thank you.

Pre-amp: Meridian 502 may upgrade to G02 if this work.
Amp: Meridian 559 for bass and Meridian G57 for mid/high
I use Meridian 605s and 200 series transports. I have used Y connectors in the past to biamp with RCA plugs and I can see no reason why you can't do the same with XLR. The quality of the Ys will be the main factor, I had good ones made and didn't notice any problems using Apogee Duetta Signatures, which are very revealing speakers.
Here are five of them, with varying lengths and prices:

I think that the only way you could get into trouble would be if the combined (paralleled) input impedances of the two power amps were not high enough in relation to the preamp output impedance. I couldn't find specs on the power amp input impedances, but the 502 and G02 have very low 47 ohm output impedances, so it would seem unimaginable that you would have a problem in that regard.

-- Al
Although of course you'll have a problem with different volumes being put out by the two power amps if their gains don't match. And they probably don't, considering their different power ratings.

-- Al
Thanks for all your suggestions. I also done this with RCAs but not with XLRs. I found the specs for G02 and G57.
G02 47ohms out and G57 32k in, but I can'nt find the specs for 502 and 559.
I talk to Meridian they said that the 559 and G57 have the same Gains and the design of both Amps are very similar. I guess their specs are the same too. I will check out those web sight. Thanks again
The 502 is also 47 ohms out -- you can see that here:

Assuming the 559 is 32K in, like the G57, you would have 47 ohms working into 16K, which is certainly fine, and even if the 559 were as low as 10K you would still be fine.

And since they are saying that the gains of the two power amps are the same, you are good to go!

-- Al
I am good to go! I will go to a local dealer here to ask them if Analysis Plus or Straightwire can make me a set.
Thank you.