Original Quads (57) - the perfect amp

I'd take the 57's and 25/25 combo over any tube amps - except the Futterman OTL's - any day - speaking from years of listening! 

I sold my Bedini 25/25 about ten years ago. It needed the filter capacitors replaced, which the buyer was willing to do.

@OP The First Watt F8 works well.

But any quality power amp will need a decent preamp to go with it.

Depending on what you are using as a pre, it may be worth upgrading that before the 303 which, while not the last word in transparency, does work well with 57s.

Bedini back in business?

http://bediniaudio.com/

If you have any DIY skills, consider these. I made half a dozen of them - and still use two of them in my HT, running Magnepan MMW. Clear, musical sound and dirt cheap. The better the parts, the better they sound.

https://sound-au.com/tcaas/jlhesl.htm

If the link doesn't work, Google  "J L Hood amp for Quad".