VAC Vintage Mk II - Manual

VAC VINTAGE WILLIAMSON POWER AMPLIFIER
Operating Instructions
DO NOT OPEN THIS UNIT - THERE ARE NO USER SERVICEABLE
PARTS INSIDE. DO NOT REMOVE THE BOTTOM PLATES. LETHAL
VOLTAGES ARE PRESENT WITHIN THE CHASSIS. DO NOT EXPOSE
THIS UNIT TO MOISTURE OR OPERATE IT IF WET.
VACUUM TUBES BECOME HOT ENOUGH TO CAUSE SERIOUS
BURNS. NEVER TOUCH A TUBE WHEN THE UNIT IS ON. IT MAY
TAKE SEVERAL MINUTES FOR THE TUBES TO COOL DOWN AFTER
THE UNIT IS SWITCHED OFF.
DO NOT PLUG INTO AN AC SOURCE UNTIL ALL CONNECTIONS
ARE COMPLETED.
Introduction
The Vintage Williamson is a single chassis wide-band low-feedback stereo amplifier
conservatively rated at 35 watts per channel. It is to be operated only from the voltage
labeled on the back of the chassis (100, 120, 220, or 240), 50-60 Hz. Please contact VAC
or your dealer if the voltage in your area does not agree with the label. The fuse is a slow
blow type of the size labeled on the back of the chassis. A tube cage is available as an
option.
The basic Williamson design was first published in England in 1947, and was the mainstay
of the original high fidelity movement. Notable features of this circuit include:
- direct-coupled input amplifier and phase splitter, resulting in low phase shift
- inherent precise balance of the phase splitter (if properly executed) at all frequencies
and level, resulting in excellent push-pull balance and low distortion
- a unique bias/balance circuit that allows monitoring and precise adjustment of the
output tubes for maximum power, minimum distortion, and natural sound.