was going for a pair of refurb'd originals when this new, unused pair popped up for just a bit more. Sold the MC275 MkV in a day and replaced with these 60th Anniversary MC75s. A nice step up in sonics from top to bottom. Especially after rolling the small tubes to Tung Sol and Phillips and Gold Lion KT88s in the outputs. I'm very pleased. Using a Mcintosh C2200 preamplifier and driving a pair of Wilson CUB speakers.