Looking for a tube phono pre

I bought a used Zesto Line Stage preamp and it is absolutely the best gear I have ever owned.   They specialize in phono preamps, check them out.   I sent my unit in for some upgrades and their service is the best.  1st class all the way.   When the time comes for me to get back into vinyl I will be looking for a used Zesto

I recently purchased the Yoshino EAR Phono Classic (or Phono Box in Europe) and I will vouch for its quality. A definite step up from my long-time friend, the first iteration of the Acoustic-Signature Tango. Best part for a person who hates to jump through a lot of hoops just to play records - it's got ZERO dip switches. You get different gain from the MM or MC button in the back and it's perfect for most cartridges. You can fine-tune yourself into an insane asylum while I'll be pulling another record out of its sleeve.

I have a vintage Marantz Model 7 on Audiomart

Another recommendation for Zesto. I have owned the Andros 1.2 for almost 7 years and have enjoyed it a great deal. It sounds wonderful, has been 100% reliable, is easily adjusted and has the flexibility for loading and gain to accommodate just about any cartridge.

A used Andros 1.2 would be well within your price range and even a used Andros 2, which has the new power supply, could be had at the upper end of your price range or close to it. 

Why are you unhappy with the Sutherland? Too clean, detailed and accurate? Maybe improving the cartridge will do more for you.