Valve Amplification Company VAC Sigma Preamplifier Instructions Manual issued - 3 March 2008 Revised 2 April 2008 Please read carefully before installing Copyright 2008 by Valve Amplification Company. All rights reserved.
WELCOME Congratulations on your purchase of the VAC Sigma Preamplifier, and welcome to the family of VAC owners! Your VAC is designed not to the latest fad but to substance, providing the highest quality of sound. Time spent familiarizing yourself with this manual will be well rewarded. It is our goal to provide instruments of the highest quality, be informative to all of our customers, and to provide responsive, effective customer service. Please feel free to contact us if we can be of assistance.
GENERAL PRECAUTIONS & SAFETY NOTES 1. DANGEROUS VOLTAGES EXIST WITHIN THE CHASSIS. DO NOT REMOVE CHASSIS COVER UNTIL UNIT HAS BEEN SWITCHED OFF AND UNPLUGGED FROM THE WALL OUTLET (POWER) AND ALL COMPONENTS FOR 15 MINUTES. TUBES BECOME HOT IN USE, AND CAN CAUSE INJURY. DO NOT EXPOSE CHASSIS TO MOISTURE. DO NOT PLUG INTO AN AC SOURCE UNTIL ALL CONNECTIONS ARE COMPLETED AND ALL COVERS ARE INSTALLED. 2. Complete all signal connections before connecting the AC cord to the wall outlet and turning the unit on.
INSTALLING THE SIGMA PREAMPLIFIER Physical requirements: 1) Provide Adequate Ventilation. 2) The chassis cover will become warm during normal use. 3) This component must be installed in a secure, properly built (and ventilated) stand, cabinet or enclosure. It could inflict serious injury or property damage if it falls, or if the stand upon which it is placed tips over. This concern is particularly important in households with small children who might try to climb furniture.
OPERATING THE SIGMA PREAMPLIFIER Front Panel Controls: Although most of the front panel controls (Volume, Power, Mute) are self explanatory, VAC has outfitted this unit with several advanced features which bear further description: Phono Section MM (option): When fitted, input “L6" will be connected to a discrete, pure tube phono preamplifier, providing 40 dB of gain, suitable for use with MM (moving magnet) and many high-output MC (moving coil) cartridges.
“Mute” and “Operate” condition. When muted, a red glow will be observed in the LED. On occasion the preamplifier may seem not to have responded to a turn of the “Mute” knob; this is due to “contact bounce” in the switch. Simply turn the knob again until the desired condition is attained. REMOTE CONTROL The remote control allows for wireless adjustment of “Mute” and “Volume”. The remote wand is powered by two “AAA” batteries. These should be of the alkaline type.
MAINTENANCE Chassis Care: Although your VAC chassis and faceplate are extremely durable, their finish can be scratched, chipped or damaged if improperly treated. Cleaning with a soft, damp cloth while the amplifier is switched off and unplugged should restore the finish to its original lustre. Never clean this component with harsh or caustic cleansing agents. When shipping your unit, be certain to wrap the amplifier in the cloth, tissue or plastic wrap in which it was originally packaged.
GENERAL INFORMATION ABOUT TUBES It is a truth that each brand of tube sounds different in a particular high resolution circuit. This is because no two manufacturers make a tube type in quite the same way, and the central tendencies of the performance parameters will differ slightly with each maker. This sonic variability may at first seem a liability, but further thought will reveal that it is an advantage.
VAC SIGMA PREAMPLIFIER SPECIFICATIONS (typical) Type: Vacuum tube line stage with home theater (direct power amplifier) mode.
SIGMA PREAMPLIFIER REGISTRATION mail to VAC soon as possible.
