$500-600 Used Tuner

I just noticed that you failed to mention which late 70's tuner you have.
I thought all the responces here are good, and great ideas. I got a lot of ideas from the tuner info site. There are a LOT of tuners to choose or try to find or mess around with.
I have a sunsui tu-717 sitting on top of a accuphase t-101 right now. I much prefer the sound of the accuphase to the sunsui, but I can see where some might prefer a fully alighned and modified sansui to it. (just as some here have stated their preference over the magmun dynalabs).
The mac's are HIGHLY regarded, but then that throws in more complications/debate, as many fans of others state their preference over mac's.
And as many of these great tuners sound different, and have different strenghts, what is really cool is that , as stated above, is that there are some lines that have lesser tuners in the 50-150$ price range that sound almost as good, depending on what you want or need.
I guess what I am trying to say is that perhaps if you stated what you have and what perhaps you are trying to achieve that might make this thread really come together.

I love my MD100 too, but my old NAD 7400 receiver's tuner ($)section (4300?) is a beauty. Chase an old 7100 or 7400 just for this tuner. You'll be surprised! Selectable IF, cancellable noise-filtering, lots of presets, and a big weighted tuning dial! Yum.
Another ($$) is the Audio Refinement Complete Tuner. It's a beauty at about $500 used. Approaching the used MDs, though. ENJOY! Nothing like clean live feeds once in awhile, eh?

Der, thanks Brianmgrarcom. I guess sometimes I don't bring in all my stations clearly.

Hey Onhwy61 - for the record, Don Scott is a good guy and he's always been helpful when we've asked him something, but TunerInfo isn't "his site." Check the "Our Staff" page to see who's responsible for the site. Most reviews state who wrote them, and you'll see Don's name mentioned in a reviews whenever he had something to add.