I have an older Tri-Vista integrated. Different animal than your 308 but I'm sure similar in some ways. Mine really benefited from a silver conductor power cord. Injected some real verve and jumped everything up a notch.
How does my MF A308 compare to modern integrated amps in the $3000-$6000 range?
Are more recent amps in the $3000-$6000 range superior enough to warrant an upgrade?