VAC PA100/100 POWER AMPLIFIER
Operating Instructions
DONOTOPENTHISUNIT-NOUSERSERVICEABLEPARTSINSIDE.DONOT REMOVETHEBOTTOMPLATE.LETHALVOLTAGESAREPRESENTWITHIN
THE CHASSIS. DO NOT EXPOSE TO MOISTURE OR OPERATE IT IF WET
VACUUMTUBESBECOMEHOTENOUGHTOCAUSESERIOUSBURNS.NEVER TOUCHATUBEWHENTHEUNITISON.ITMAYTAKESEVERALMINUTES
FOR THE TUBES TO COOL DOWN AFTER THE UNIT IS SWITCHED OFF.
DO NOT PLUG INTO AC UNTIL ALL CONNECTIONS ARE COMPLETED.
Introduction
The VAC PA100/100 is a single chassis wide-band low-feedback stereo amplifierconservativelyratedat100wattsperchannel.Itistobeoperatedonly fromthevoltagevisibleontheconfigurationcardlocatedunderthefuse.Please contactVACoryourdealerifthevoltageinyourareadoesnotagreewiththe label.Thefuseisaslowblowtypeofthesizenotedonthebackofthechassis. A tube cage is available as an option.
TheinputcircuitofthePA100/100isderivativeoftheWilliamsondesign,which wasfirstpublishedinEngland in1947,andwasthemainstayoftheoriginal highfidelitymovement.Notablefeaturesofthiscircuitincludeadirect-coupled input amplifier and phase splitter, resulting in low phase shift, and inherent precisebalanceofthephasesplitter(ifproperlyexecuted)atallfrequenciesand levels, resulting in excellent push-pull balance, stability, and low distorti
TheoutputstageisderivedfromtherenownedPA90C,featuringindividually adjustable "fixed-bias" and partial-triode ("ultra-linear") operation.
Premiumpartsareemployedthroughout,including14pound22sectionbifilar- woundultra-widebandoutputtransformers,polypropyleneandpolystyrene signal capacitors, high current rectifiers, low ESR power supply, and proprietarywiring.Thequalityofpartsandcarefullayoutallowstheuseofvery little feedback for high sonic purity and low distortion.
