Help choosing a receiver/amplifier.

[Something/Rowdy]

I'm a novice audiophile, and I need help choosing a receiver/amplifier to replace my old Harman/Kardon. I use my audio system primarily for listening to, and tape recording from, FM radio, and for playing cassette tapes and CD's. I have pairs of 8 ohm stereo speakers in five rooms of my house so I have up to five pairs of speakers playing at the same time. (I have a protected speaker switcher that I use to turn speakers on or off, and I never have them cranked up very loud.) I'll include a list of my stereo components below.

What kind of receiver/amplifer should I get for my purposes? In particular, how many watts per channel should I have to power ≤ 5 pairs of speakers? The more specific your advice can be about the type and model amplifier I couold get, the happier I'll be. (You should also know that I'm a soon-to-be-retired teacher with not a lot of dispsoable income.)

Here is a list of my current stereo components:
Receiver/Amplifers: Old Sony STR-AV850, and very old Harman/Kardon 490i
Casette Recorder/Players: Sony TC-C5 five cassette deck, and Sony TC-WE 835S dual cassette deck
CD Player: Sony CDP-CX335
Phonograph: Denon DP 15F
Speakers: Two sets of Bose 5Series III Acoustomass 8 ohm stereo speaker systems,
and two sets of JBL 2500 8 ohm bookshelf stereo speaker systems,
and one set of Realistic Minimus7 8 ohm outdoor stereo speaker system.
Speaker Switcher: ADCOM GFS-6 Speaker Selector

Thank you in advance for your advice.

[bubbagump]

I've found is the Panasonic SA-XR70S. It's an all digital path receiver with all connections you'll likely need. Aside from very clean sound, it has hdmi, component video switching, and a long list of other features. I use it to drive a pair of 4 ohm book shelf speakers. On the down side, feature control is comboned into a minimum of knobs and drill down menus. Until I figured out how to adjust it for the speakers it's driving, it was being driven into protection. Read the manual and you'll be ok. Great receiver, great price.

[avraham]

Why not another harman kardon. I have an AVR430, I bought at ComUSA for $300, a year ago. I am very impressed with the performance.

[SlumpBuster]

For such an application, and based on the other equipment you are using, I'd get one of these Yamahas: http://www.crutchfield.com/S-ZjADgn3qTb6/cgi-bin/prodview.asp?i=022RX797

If you google it, you can find better pricing too.

[nightflier]

Maybe I'm the only one who's concerned about this, but to drive five pairs of speakers, even with the Adcom switcher, you would need an amp that is stable to very low impedance swings. The only amps I know that can do that and aren't too expensive are second hand Aleph series Pass Labs amps. These can be had for around $600-800. Here's an Aleph 3 that's currently at $416 on eBay:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ih=008&item=180008824957&rd=1&sspagename=STRK%3AMEWA%3AIT&rd=1

Keep in mind that these amps run rather warm and they won't be cranking out lots of amps, but that's OK for your application, I think. Harman amps are also quite stable, but the newer ones may not be as good as the ones from a decade or so ago.