This is a very cool custom made, hand built tube bass preamp that made for me by a friend of who's in the vintage amp rebuilding/restoration business. It is designed to be (in his words) a sort of "hi-fi B15 front end". Very simple controls: Vol, baxandall style wide 'Q' bass & treble controls. 1/4 in and 1/4 out. 2 rackspace. Dig the punk rock spray paint job... ;-) It sounds amazing: very warm, fat and chewy, has a 3 dimensional sound, and has just the right amount of pleasing but subtle hair to it when pushed. The eq controls are wide bandwidth with powerful control. all the components are top notch. It has a TON of clean gain. I have been using it as a front end into a variety of SS bass heads and it sounds awesome, but I just don't use it these days and could use the cash. Please see the pics below and the basic schematic sheet that the builder provided. Questions are welcome, I'll do my best to answer. I'll include the 6SL7, 6H9C, and 6SN7 (Jan 6SN7WGTA) that came with it. $600 shipped in the CONUS. might trade for the right micro head, like a TH500 or F500.