How do I get the best audio out of my A2?

for lossless, yes, you are out of luck.

you can still get DTS over optical (downmixed from truHD and DD+ to DTS @ 1.5mpbs), and your receiver should be able to decode this.

Optical/Coaxial can be a problem for certain older AVR's. There's been many posts regarding garbled center channel and such. I believe it had something to do with the high bit-rate DTS from the A2. You might want to try it first and see what you get before jumping the gun on a new AVR. My setup is not high-end by any means, but my Yamaha does a really nice job with the DTS stream from my A2. Don't knock it until you've heard it.

Are you really disappointed with the DTS that newer audio is converted to by the player? For the vast majority of people even more audiophle types, this is amazing audio already.

By the way, without some really good speakers and reasonable acoustic properties in your viewing area, you may not be able to hear the advantages of the lossless stuff via a new AVR anyways. Food for thought....

Dissappointed? not necessarily.
Did I expect "better" sound from 1.5mpbs available bitrates sampled from higher bitrate and lossless original sources? Absolutely!

I already addressed this to you earlier:
http://www.avsforum.com/avs-vb/showp...4&postcount=27
and some final comments:
http://www.avsforum.com/avs-vb/showp...1&postcount=32

again, the conclusion for me is that it is a good audio track, and not "bad" at all per se......but it could have been so much more! It's just very obvious that they just threw something together pretty quickly for those trying to use the optical out, and didn't implement a good algorithm.

A good analogy: encoding MP3's at CBR @ 128kps, instead of VBR @ 256 with LAME encoder.

LOL! I know exactly what you mean. I love upgrading too.
In that case, I think you should go out and find a really cool AVR! Have fun shopping.