I use USP-1 and Xpa-2 for song and Onkyo 809 + Usp-1 + Xpa-2 + Xpa-3 for movie. Usp-1 and Xpa-2 is good for song. Only volume gain is too lauder working with my CD player and CAS. I need add two resisters to RCA cables to step down the gain volume.
Onkyo 809 perout FL & FR connect --> HT Bypass(USP-1) and Audio output L & R(don't connect to Full Range) ---> Xap-2. So volume will control by AV 809 volume button.
但如果加部Pre-Amp 做 2 ch, 你部pre-Amp 最好有 AV by pass function 就可以成為一套完整 system. 在 2 ch 時只switch on Pre-Amp & Xpa-2 及source. Vol. control 就由pre-amp 做. 致於如何調教7.2 可以 run odes'y 或用SPL METER fine tone. Xover 要看喇叭的 spec. 一般十仔有外置X-over. AV vol. 就在AVR 調教.