Topping LA90 is what I am using now. I picked this with the same criteria as you are looking for. Low weight, Class A/B under 80 watts, runs only slightly warm. It has beat out the Benchmark AHB2 as the lowest Sinad measurements. I've sold off the heavy and hot Pass Labs X250.5, Classe Monos and have my 150 pound Enlightened Audio Designs PM 2000 for sale. It can be used as a three input integrated, high/low bias and also mono. I have tried it in mono and I didn't hear any reason to go that route so, the value proposition is high for this amp.
Best sounding low power (under 80watts) Class AB amp?
What the world needs is a nice sounding lower power class AB amplifier under 35lbs. I'm tired of power sucking light-bulb dimming Class A designs and 80+ pound Class AB immovable boat anchors on dollies. Tubes and Class D need not apply.
An Audio Research 100.2, CJ MF-80/MF-2250 come to mind. What else is there?
What do you think? I'm I the only one?
--Sensible in Springfield.