Studiomaster Valve Leadmaster 1980’s

Here is an amazing original early 1980’s Studiomaster Valve Leadmaster Tube amp head unit. These amps were made for a very short time between 1981 and 1982. It is a valve/tube amplifier featuring 5 12AX7 tubes, and 2 6L6GC tubes. It features a 5 band graphic equalizer, and on-board 16" Type 4 Accutronics (model AB2A1B) spring reverb unit, and push/pull controls.

Made in England by a company known for making high end sound mixers and studio consoles, Studiomaster, Inc decided to develop a line of tube amplifiers as the popularity of the electric guitar and demand for a different sound other than Fender, Marshall and Vox was beginning to rise. Very few of these amps were made despite their popularity amongst gigging and studio musicians of the time. And have become a real collectors item. The amp is extremely well made and built like a tank.

When launched it was an immediate success, due not only to its stunning looks but its sound. The tone and gain range could produce warm, clean sounds or powerful distortion at the touch of a switch. A number of VLMs were custom built for special customers featuring an engraved silver identity plate.

Unfortunately, due to limited production capacity and ever more demand for mixers and amplifiers it was decided to drop the VLM after only two and a half years.

Today, when second hand examples come up for sale, they often change hands for three of four times their original price.

The steel amplifier chassis measured 482mm x 76mm (19 x 3 inches) with all the valves in board so a future compact 60W amplifier head version could be made. (we believe this example may be a prototype of head version which was never released.) A Papst D.C. low noise fan was fitted to the rear panel to reduce heat build up around the output stage. The power supply used a toroidal A.C. transformer for its small size and quiet electrical and mechanical operation, important as the VLM was used in many recording sessions.

The signal path and amplifier was to be valve (tube) as transistor amps just don't come close to getting a good sound. ECC83/12AX7 triodes were used in the preamp and tone control stages although the power output valves were not the usual EL34s found in British amp designs. A pair of 6L6 beam tetrodes were used for their classic tone and punchy mid characteristic and availability in the USA, the primary target market. The output was 60 Watts driving the specially selected Fane 200L (200W) Studio range speaker. A number of 12" speakers were tried (including premium brands) during the VLMs development but the Fane came top for tone and loudness.

The 5 band graphic equaliser could be switched into the signal path expanding tonal possibilities. Four transistors were used in the design of the graphic which was powered from a 90V supply so fairly high volumes could be achieved before the inevitable transistor clipping sound became a problem.

The on board spring reverb was a 16" Type 4 Accutronics (model AB2A1B) unit selected for its superior sound over much cheaper copies. A new and very useful feature was the effects loop as outboard guitar effects processors were becoming popular at this time.

An xlr direct output socket and 4 or 8 ohm output impendence selector switch, for extension cabinets, further enhanced the VLMs flexibility.