I had a pair of MDA-300 amps that I bought new around 1990. They ran very warm, but never too hot to touch. They were recapped by Krell in 2005 and again in late 2016. They delivered very good sound and for over 25 years, I saw no need for any amplifier change. Following the latest recap, I decided that the resale value of my amps was at its max and I explored replacements.
I considered PS Audio BHK Signature monoblocks but didn't like the tubes; I liked the long Bryston warranty, but there were no local dealers for an audition; The Macintosh MC-475 sounded very nice at my local dealer but they seemed reluctant to let me borrow their demo for a weekend audition in my system, so it was scratched from my list.
I brought my local Krell dealer's DUO-300 home for a weekend trial. It delivered wonderful midrange and didn't exhibit the occasional higher frequency harshness that older Krell amps can have. Unfortunately the Duo-300 bottom end wasn't as fast and solid as the old amps. I spoke to my dealer and to Krell. They made a pair of Solo 575's available for me to try in my system. These new amps delivered the taught bottom end that the old amps delivered with a bigger midrange and the smooth high frequencies that I wanted. After 3 or 4 hours driving my Legacy Focus SE's as loud as I want them, the top of the new amps is not even warm to the touch and the fans do not appear to be running. The Solo 575's cost more than I had wanted to spend, but I bought them. It's been a few weeks, and I am still happy with this decision.
Hopefully the new amps will provide me with many years of reliable service. The new owner of my older amps has told me how pleased he is with them. I believe that he will also get many years of reliable service from them.
Later this year, I may bring home an Illusion II preamp to see how it compares to my recently recapped KRC-3. I'll be very surprised if it offers enough improvement to justify the cost.
