to improve your 555II, try something like an arc preamp. i substituted a sp3a-1 for the 565 and the whole thing opened up. dynamics espewcially. tubes in front of adcoms are highly recommended as far as im concerned. my friend use a counterpoint pre and the results are very nice, and this is with ml requests. ive been warned that adcoms are too bright for MLs but that is crap. borrow an arc if you can, you may not buy another amp......
Quality used amplifier needed
I am in the process of upgrading from an Adcom 555mkII that has been modified. My friend has a Threshold S300mkII that I have heard on my system and it sounds fantastic. Are there any other used amp I should look at in the under $2000 range. My speakers are 4 ohms and I feel I need an amp that put out 300 watts at 4 ohms and is also able to deliver high current. Thanks, CS