Picked up a M-45 amp today. Have a question about class A power output

VintInfinity

Tactophonic
I have a pair of Ads L990 that I power with a PC2002M driven by a C-65 preamp. I decided to get this M-45 to power my L780 in another location. Sounds pretty good but not as warm or controlled as the PC2002 at low levels Seems a bit brighter too.

Anyway, my question is. What is the class A output? The brochure for the m45/65/85 and c45/65/85 line lists 5 watts class a while the manual for the m45 lists 10? also is that total of per channel? I listen at 1/10w to a watt usually.
 

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The OP had another thread where someone posted a chunk of the Brochure showing a 5 watt Class A operation. This is a chunk of the Owner's Manual and it says the Class A operation is to 10 watts. I'll believe whatever @avionic says is the correct number based on his experience with Yamaha. Now that he knows there are two different documented numbers, maybe well get another comment. The other thread has apparently been deleted due to duplication.
Yamaha M-45 Specs.jpg
 
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I really don't know the correct answer. Owners manual says one thing and service manual says another. Split the difference 7.5 wpc :dunno:
 
Is power consumption 500w even when outputting around 1wpc or less, or is it somewhat proportional to output level? I ask because I saw that the M-50 has the X-Power power supply that was supposed to pull only what it needed to make the output or something along those lines.

Also, is a slight psu bzzzzzzzt type buzz when on (no hum in the speakers) a sign of anything going bad?
 
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Are you sure its coming from the transformer. If so.Not really much you can do about it. It will just be annoying.A loose lamination in the transformer. Might try tightening the four bolts on the side of the transformer.And snugging down the transformer to the chassis.
I haven't noticed anything unusual about the button press
Not concerned with the press. But arcing inside the switch.
 
Are you sure its coming from the transformer. If so.Not really much you can do about it. It will just be annoying.A loose lamination in the transformer. Might try tightening the four bolts on the side of the transformer.And snugging down the transformer to the chassis.

Not concerned with the press. But arcing inside the switch.
Ok, I will give it a listen tomorrow evening when I am able. Haven't noticed anything before though.
 
Are you sure its coming from the transformer. If so.Not really much you can do about it. It will just be annoying.A loose lamination in the transformer. Might try tightening the four bolts on the side of the transformer.And snugging down the transformer to the chassis.

Not concerned with the press. But arcing inside the switch.

It doesn't seem to zap or anything, but the buzz starts nearly immediately after the mechanical click of the button.
 
Probably just a loose lamination in the transformer core.
 
Probably just a loose lamination in the transformer core.
My pop told me the same thing. I always like to get a second opinion even though he is also highly skilled [50+ years of experience]. I should give him more credit.... thanks for answering my questions.
 
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