One of the finest bass amps out there, hand-signed serial #52 of 150 based on Lee Sklar's original Demeter preamp, combined with the Minnie 800D power amp. This thing sounds amazing--the notes practically jump out of the speaker!--but alas, it's not the best fit for my current hard rock project. In near-mint condition with no marks that I can find. Just got back from the Demeter shop where was given a checkup and had the Jensen DI installed. Full specs: All tube pre-amp circuitry Hand wired in the USA using High quality components, DC filament, full 280V high voltage supply. Classic passive tube tone controls Treble, Middle, Bass with frequency selector and presence with frequency selection. We replaced the original bright switch with our new Mode switch that lets you control the overall tone: Dark, Normal and Bright. The unit has a pre-amp output if you need to run more amplifiers. A select Jensen transformer drives our 800 watt class D Amplifier. There are two Speakon combo jacks on the back to hook up your speakers. We offer upgrades for Jensen transformer Direct outputs and a line level effects loop. The amp weighs 10.5 lbs and messures 13”wide x 5.5”high x 9”deep. Built right here in the USA in our Barn in Templeton CA. Tone section: Treble Control: The treble control gives 6 dB of boost or cut at 4 kHz (6dB per octave, shelving type). Middle Control: The middle give 6dB of boost or cut at 500Hz (wide Q, peaking type).Bass Control: The bass control gives 9dB of boost or cut at a selectable frequency of 60Hz or 120Hz (6dB per octave, shelving type). Presence Control: The presence control gives up to 12dB of boost at a selectable frequency of 2kHz or 4kHz (active type, 6dB per octave). Mode switch: Dark, is a high frequency cut fatting up your fundmental. Normal, flat opertion showing off more overtones. Bright, brings out the overtones on the dullest basses or speakers. Internal Volume Trimmer: This control is designed to match the output volume of the VTBP-M-800D with the sensitivity of any Bass. Optional, Studio Output: The VTBP-M-800Dm- features a mic level Jensen DB-E output transformer for a balanced studio output. Effects Loop: in/out line level Power Amp Outputs: Operating at 4 (800w),8 (500w) or 16 ohm (250w). 1/4” & Speakon Preamp Specifications Inputs: one instrument level 1/4” jack. Output impedance (line): > 1 kohm, (unbalanced) Minimum load impedance: 10K Input impedance: > 1megohm Maximum output: + 24dBV EQ gain : + or - 12 dB Signal to noise ratio: - 80dB THD : .5% Outputs (preamp): 1/4” unbalanced , Optional 3 pin XLR Direct out Frequency response : 10Hz to 40kHz Tube: 1-12AX7a selected 1-12AT7 Operating voltage: 115V or 230V AC Power supply: 280V DC Filament: 6.3 V DC Power Amp Specifications Outputs (power amp): 1/4” Speaker & Speakon Output impedance (power amp): 4 ohm, 8 ohm, 16 ohm Output Power (power amp): 800 watt RMS @ 4 ohms, 400 watt RMS @ 8 ohms List price on these is $1829 with the Jensen DI, asking $1300 plus shipping.