Yamaha M-80 Amplifier Connection Options

The M-80 is in a class by itself when compared to anything Yamaha ever made. I don't think it is 250 watts per channel (can't recall)? However, the first 10 or so watts are class "A" which makes it so nice.
By using a pair of output, ie A & B, you are forcing the unit to use its internal impedance matching hardware. I wonder if this will impede the sound?
Personally, I would bi-wire using only the A jacks with Y splitters and see how that sounds. It may be slightly easier on the amp to use A&B or B&C but you may loose some dynamics??? Your speakers should be quite an easy load on any amp, so don't worry.
By the way, when playing softly, the amp will run extremely hot. That is the class A circuitry. Don't worry. It will only run cooler if you are blasting music and with 93db speakers, I doubt you will need more than 10 watts ever!

Good advice all; the specifications list 250 watts at 8 ohms but what it actually will push is anybody's guess. After reading the connections page in the manual for the 10th time I'm going to try wiring using the B & C channels. This set up will be in series and logically should give me a 16 ohm resistance???

I also have a question on a bi-wiring set-up. My speakers are JMlab 8 ohm speakers capable of 50-150 watts and bi-wireable and my amp is a Luxman L-430 (105(?) w rms/channel. The amp has an A (L+R) and B (L+R) speaker inputs. It accepts 4-ohm - 16 ohm speakers if only the A-output is engaged and 8ohm-16 ohms if A+B speaker outputs are used.

The crux of my question:

I can bi-wire either to A speaker output on the amp alone or separate out the BASS/mids to A and the tweeters to the B speaker outputs on my amp. In fact I did this for a while with great sonic results.

However, I noticed that the amp was getting very hot and so I wondered if by this setup, the nominal 8-ohm resistance of my speakers had been reduced to 4 ohms which is below what the amp specifies for A+B speaker outputs being used simultaneously. When I limit the bi-wiring to the A-speaker output, less heat is generated, but the sound isn't as nice (better separation, depth, etc.)

If I am reducing the ohms to 4 with the A+B bi-wiring setup, is there ant conceivable way to get the same advantages by hooking up the 2 speakers in series. My mind blows a fuse when I try to think about this.

Any advice would be appreciated.

Harold

Harold,
My guess is that you are making the amp work harder by matching the impedance between the 2 halves of your speakers. I don't know your amp but know the Yamaha very well. The Yamaha makes some HUGE compromises when adding pairs of speakers, especially the C pair. A&B are Parallel which is halving the impedance. A,B&C are using a combination of parallel & series to keep the impedance reasonable. I don't know why they ever made this option available since the amp is so nice and the feature is so junky?