Need Good Service Technician to Fix Noisy ARC 6B

My Old 6B is acting up and ARC will want $700 plus to look at it. Does anyone know of a good tech with experience on ARC tube preamps??? Very noisy phono stage and rushing sounds come into line stage after a few hours...Turn it off and then on again it works for a while. But phono stage is always noisy. Any help would be greatly appreciated.
You may check with Steve Huntley of Great Northern Sound. They do excellent mods to ARC gear (Steve used to work for ARC). Don't know about repairs, but their Standard upgrade is around $750, and would be money better spent than a simple repair, if the ailing components happen to fall within what is included. I had them do a Standard Upgrade to my LS-2B and was very happy with the results. Steve may be able to point you in the right direction for a good repair resource.