Depends on your tastes, but my JP80 and I like NOS Telefunken 12AX7s, as well as Teles in the power supply. Don't know if the JPS uses any other types of tubes. I find Mullards to be too bright and thin for my tastes in this circuit. The Ei 12AX7s also sound pretty good in Jadis preamps. You can check the many other tube threads in the site archives for reputable dealers. I use Andy Bouwman of Vintage Tube Services, as while he charges top dollar he checks out and stands behind everything he sells, and you know you're getting the real thing. He's also good with suggestions as to which brands of tubes work well with different makes of equipment.