My Yamaha clips at 3/4 volume

Western,
Something doesn't add up here. Your Yamha M45 amp is rated at 180 Watts rms @ 4 ohms, into 4 ohm speakers that are efficient enough to have been successfully driven by a 10-watt rms Trends Audio T-amp! (Dingus' 2nd Agon system, Bedroom bliss with the T-Amp).

You should have way more than sufficient power to drive these speaker loads.
-----------------
Give us more details, and I'm confident one of our amazing A-gon Gurus will surely be able to help you in isolating the problem.
e.g.:
When you mention 3/4 volume, are you a) referring to the volume pot on the pre-amp, or to b)the peak power meters on the amp? If a), what peak power readings are you getting on the amp w/o failing?

Is your "Auto Class A Switch" deactivated? If not, try switching off to run in full A-B mode. (This could possibly effect handshake with pre-amp?)

What sources are you using?
Was this system ever more responsive?
What last changed?
What other components do you have to swap out for testing?

Good luck!

Hi Western,
-By now you've probably figured out that "Class A" relates to selecting a more refined but lower-wattage element of your amp, and is unrelated to the speaker "A" and "B" selections. So, connecting the speakers to A is fine. As Elevick indicated, just use one speaker pair at a time with this amp. Also suggest you switch off the unused speaker channel.

-Are you saying that output volume with these speakers was previously higher using Yamaha A-700 or other gear, or that you want greater volume that you haven't obtained yet?


Elevick,
Glad to see your advice here as an M45 owner! If these are high efficiency speakers, should Western opt to power them in Class A mode if possible? What preamps did you use with M45?

Agree that opening up volume pot at amp input is the next thing to try.

But at a risk of muddying the waters, there are a couple of Yamaha amp reviews around that also noted clipping problems using newer preamps. The solution at the time was to increase resistance at the amp input level until the clipping was brought under control.

This would suggest that if setting the volume pot (for speaker A) wide open (fully counterclockwise, to infinity symbol) as recommended doesn't solve the problem, you might also then consider a test to go the other way.

That is, incrementally increase amp input impedance by turning the pot clockwise in steps, while turning up the preamp volume to keep overall output volume relatively constant.

'Nuf said - enjoy!