You said reasonably priced. Look for a used Hafler dh-500 on Ebay or here(400) and then send it to Musical Design for the Platinum Mod(1399) and you will be happy as hell. Total price with shipping on both purchases around 1900 if you have the amp when purchased sent straight away for the mods. I have been using a dual mono Musical Concepts modified Adcom 555 for some time on my 3a sigs. Back in the late 80's when the vandy 2c's first came out the Adcom was the perfect match because it's weakness played into the vandersteen strengths. It was the BUDGET audiophile system of it's day.
