You will probably have good luck with Schiit electronics. They are the primary electronics used by Grado in their development, they are mid priced but intentionally no-compromise, innovative designs built and marketed to avoid the egregious markup of the connoisseur brands; and by many peoples estimation, Their higher end items, all below $2000, and some much less,have few if any Superiors at any Price. You have choices of different voltages, balanced or unbalanced (true balanced), and many of the models not only are tube or tube hybrids, the company also makes actual solid-state tubes so that you can roll in and out any tube in the 6922 or 6DJ8 class, actually at least a dozen tube designations are perfectly acceptable, as well as plug-in transistors that go right into the tube sockets. The units are made entirely in the US, all components sourced from companies in driving distance from the headquarters, and the designers are veterans of some of the more innovative true high-end companies, and all they build are DACs, Amps, and all in one units for headphone systems… Although their amplifiers can beautifully drive efficient loudspeakers and or function as purist preamps. You order directly from their website, and they have five year warranties, no questions asked Return policies after listening at home… I don’t think there are any limits to where they will ship. I’ve owned about half of their product line and they have all been dynamite.