Wotan — with these monoblocks, the name is no exaggeration. VTL's (Vacuum Tube Logic) MB-1250 still ranks among the most powerful tube amplifiers ever built: 24 6550 output tubes per side operate in push-pull, delivering up to 1250 watts into 5 ohms in tetrode mode and 600 watts in triode. The pair offered here was built by hand at VTL in the USA under Luke Manley in 2001, as an MK2 in the 240-volt version; pair prices at the time ranged from 25,000 to 32,000 US dollars depending on the version.
The output stages carry original Russian Svetlana 6550C tubes of the Platinum generation — 48 in total, regarded by connoisseurs as the finest of the series. All tubes have been tested by a specialist, show only a few operating hours, and are labelled with their measured values, additionally documented in a spreadsheet. At current prices of 179 to 229 euros apiece, this tube complement alone represents a value of roughly 8,600 to 11,000 euros. The input and driver stages — two 6350s and one 12AT7 per side — are likewise fitted with premium tubes.
As a workshop specializing in the restoration of valuable audio equipment, we went through the monoblocks thoroughly in October 2025 and tested them for operational safety to DGUV 3 (DIN 0701/0702); a major service had already been carried out in 2021. Among other things, the diode boards were renewed with original parts, along with LEDs, contacts, switches and connectors; the filter capacitors measure like new, and all bias settings have been made. High-quality AHP fuses are installed, with further special fuses included. The amplifiers run reliably; a slight transformer hum is inherent to the design. Visually, both units are in very well-kept original condition without visible damage.
A pair of this magnitude wants some planning: each monoblock weighs around 127 kilograms, power consumption reaches 1800 watts, and the house wiring should provide a 16 A type C fuse per amplifier and a cable cross-section of at least 2.5 mm² — we are happy to advise. The scope of delivery comprises both monoblocks with their original crates and the tubes described. We recommend viewing and auditioning at our premises in Wuppertal by appointment; delivery and installation can be arranged on request.
