Hi,
Any of these three I'm sure will do just fine. Just pick the one that looks best to you.
Or ask your wife which one she loves best.
And just check for rotary (if possible) tone controls for bass and treble.
Also, two sets of speakers (A & B).
Power wise, they are all equivalent.
Brand wise, they are all good.
Check also for zone two capability.
The Onkyo might have the best tuner section, perhaps.
Which one are you more tilting for? Just get that one.
*** Get the Onkyo TX-8555, it has rotary knob controls for the Bass and Treble, two sets of speakers (A & B), second zone capability, 4-ohms capability, simple design, nice remote control, preouts, WRAT technology, all the stuff you want and more. It is also user friendly and has an easy manual to read. That's the one to pick, period.
The HK and Marantz are hiding behind the curtains, like they have something to hide, just stay away from them. And besides, the Marantz is probably boosting his power and weights too. And with a height of 6.5 inches, it's just ridiculous for a stereo receiver.
Onkyo it is, get that one.
Bob
