Picked two relatively low-powered amps for $120.
The Audiosource AMP 1/A is 80 or 85 watts per channel and is fed solely by the Bluesound Vault 2 sitting next to it. It will live in our guest bedroom, powering a pair of KEF iQ10 bookshelf speakers. They were the first KEF speakers I ever got, a gift from my then 24-year old younger son. They have never sounded better, the bass out of them now from this high-current amp is shocking! Those speakers are going nowhere.
The Luxman M-111 is an even-lower powered 4-channel amp. Rated at a nominal 25 watts per channel, I have it running in 2-channel bridged mode to my main KEF R500 front speakers. It's fed by the pre-outs on the NAD T758v3 AVR, and I did have to boost the analog audio pre-amp output for those two speakers by +3dB to get them back to the same level they were at with the receiver itself. In the receiver's "analog bypass" mode (similar to a Marantz-Denon "pure direct" mode), it does drive the R500's bass better than the AVR did in the same mode. Like all amps, it's not watts that matter, but current and the total design of the amp. No, it doesn't sound profoundly better, just a little more bass control.
The Luxman will probably get upgraded to a more powerful yet similarly-structured Class A-B amp in the future. The only analog source I have remaining on that system that can take full advantage of this amp is the analog outputs of my Sony CD player. This was a cheap way to learn more about what power amps can and cannot do, and I think it was worth the effort.
