Tung-Sol 5881 Matched Power Tubes Hard Duet 5881 Matched Power Tubes Hard Duet The Tung-Sol 5881 is a very reliable, general purpose power tube much like the 6V6 These tubes are available in different grades depending on how much distortion is desired Matched set Soft, medium, and hard style descriptions refer to break up modes of the tube for an overdriven guitar signal