I agree with Arthur....I have the 501's and compared them to the 402. Both were excellent sounding amps, the 501's had just a little more presence in the midrange area but they were really close. I chose 501's because I really wanted monoblocks and I drive Thiels so I wanted as much power as I could muster under 10K.
The 501's love Kimber 8TC, don't know if it's the size of the guage or not but they sound better on my system than many others I've tried.
The 501's love Kimber 8TC, don't know if it's the size of the guage or not but they sound better on my system than many others I've tried.