Best sounding,reliable, tube amp below $700 used

Agree with Mwilson--QS Mini-Mite Monos are excellent for the price ($998 new, ~$650-700 used).

Thanks for the replies, I've read about the mini mites on an old post here, and also the Conrad-Johnson mv-55 seems to also have a lot of backers. Please keep the opinions going.

What type of speakers will the amp(s) be driving and what are their specs?

And what some tube amps that you've heard and liked along with others that you didn't?

Well, my system now is comprised of an Adcom GFP-750 preamp, and PSB Alpha speakers, but I will be replacing the PSB with Revel M12s in the near future.

As for amps that I've heard, I really havent heard that many, but I have liked the sound of the Krells and Levinsons. I've listeded to a Rotel integrated and wasnt too impressed with that. I also had a Marantz 2330 that was okay, but not outstanding. I seem to like systems that bring out a wide soundstage, and detailed vocals, especially female. Does that help at all?

A rebuilt with Curcio power supply mod-Dynaco ST-70 with very good tubes might be the ticket and surprise you too.
I replaced my Threshold S/300 with the Dynaco which is more musical and doesnt have the Threshold midrange dryness.
The Dynaco doesnt have the power of the Threshold or the bass control,but believe it or not, the Dynaco is not that far behind (with Curcio ps mod and vg NOS tubes) which adds a much improved midrange tubes are known for.
A few for sale here within your budget.