The Art Audio Diavolo is an outstanding, modern, 300B, Class A, single-ended-triode, no-negative-feedback, tube-rectified, high-current, stainless-steel-chassis, all-vacuum-tube amplifier, designed and manufactured in England, and still imported into the U.S. It has a volume control, one pair of RCA inputs, and one pair of speaker-output terminals. This amp is single-owner, purchased in 2000, and used exclusively in a personal audio system. It is fully functional, in good condition, with moderate wear on surfaces. The Diavolo’s virtues are musicality, tone, resolution, dynamics, power, and imaging. Several early reviews gave it an outstanding rating. One review stated, "The Diavolo just brings a greater degree of immediacy and emotion to the music, not to mention a better sense of pace and rhythm.” The amp was originally configured in the U.S. for KR VV32, KR 300 BXLS, and KR 842 VHD output tubes, producing on the order of 13 watts per channel. The greater output was known to create reliability problems. This amp was recently serviced by the current U.S. importer, Hudson Audio Imports (website: hudsonaudio dot com), and restored to the original 300B, 8-9 watt configuration. It can still use the KR tubes indicated, as well as standard 300B tubes. Rectifier tubes are CV378/GZ37; small tubes are 6922/6dj8 and 12BH7. A particular feature is large, powerful transformers that lend an apparently big output capability that allows the amp to power speakers at 88-90 dB and higher efficiency. This amplifier has a backstory, so communication with a buyer is needed. Also, the amp might produce a slight “buzz” in some circumstances, which could be due to grounding, tubes, or something else. The Diavolo will be delivered with a full tube set, including 842 VHD output tubes, and extra NOS small tubes. Please contact me if you are interested in a terrific, beautiful, single-ended, Class A, high-current, 300B amplifier at a reasonable price.