I've compared the two. While the MC402 is rated at 400 watts, it certainly seems underpowered for that rating. When driving Dynaudio speakers, the annoying orange "clip" indicator kept coming on.
With the same speakers, the 501's were obviously WAY more powerful as if they actually came close to the manufacturers specification. Not only that, they just sounded better - even at lower volumes. And... the orange clip indicator light never came on when driven at deafening volume levels.
Honestly, I've listened to the same speakers driven with 250 watt amps which handled the Dynaudio load better than the MC402. If you're in the market for either of these amps and can afford the 501's... that's the better choice.
With the same speakers, the 501's were obviously WAY more powerful as if they actually came close to the manufacturers specification. Not only that, they just sounded better - even at lower volumes. And... the orange clip indicator light never came on when driven at deafening volume levels.
Honestly, I've listened to the same speakers driven with 250 watt amps which handled the Dynaudio load better than the MC402. If you're in the market for either of these amps and can afford the 501's... that's the better choice.