The one and only VLM... 1981 - 1982

By the early 80s Studiomaster had a firmly established market in the growing pro audio world that rivalled many larger companies in quality and innovation. Still relatively new, the company was not saddled as just a mixer company which allowed freedom in perusing other product areas.

Demand for guitars continued to grow and attention was turned to guitar amplifiers. Apart from the few old established brands there was little in the way of quality combos that sounded good and were affordable.

Once the decision was taken to build a Studiomaster guitar combo it was agreed it had to be something special and the result certainly was. There was to be no compromise in features or sound and over the next 9 months developed several prototypes. See INSIDE section below for more technical info.

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. 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.