this should bring down the 661 to more affordable levels...
what is the main difference between the 661 and 663? anyone...thanks!
Yamaha 663 decodes the latest lossless audio formats such as TrueHD, DTS-HD, DTS-MA, etc. while 661 does not They are the audio formats used in Bluray movies. Lossless offers better sound and cinematic experience as compared to compressed AC3 (aka Dolby Digital) and DTS sounds. A good analogy is CD and mp3. CD sound is lossless [as well as FLAC, if you are aware of it) while mp3 is lossy (there are loss in audio quality). A receiver that decodes lossless format is nice to have for future proofing. Although at present, only a few bluray player can transmit lossless sounds via bitstream for the receiver to decode; so it's not an imperative feature to have especially if you don't plan to go HD anytime soon.
Yamaha 663 was a strong contender of Onkyo 605 (now 606) in other countries because they are entry level receivers capable to decoding lossless format. The main strong point of Yamaha 663 over Onkyo 605/606 is the pre-outs. At present, only Denon's mid-end 2808 receiver can decode lossless format. The soon to arrive entry-to-mid level Denon 1909 can decode lossless format so the competition is going to be tough this year.
I guess the reason why the distributor here is not importing and selling 663 is because they still have to dispose their 661. They are going to have a harder time disposing them come September when Denon 09 series and Onkyo 06 series receivers invade the Philippine market.