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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. We can be reached:
Telephone
941 952 9695
Fax
941 952 9691
info@vac-amps.com
Website
www.vac-amps.com
We look forward to being of service, even as you have many years of enjoyment from your
VAC Sigma Preamplifier.
Kevin M. Hayes
President, VAC
INTRODUCTION
The VAC Sigma Preamplifier is an all new design derived from the VAC Phi Beta, and
employs four twin triode vacuum tubes operating in Class A. This unique design provides
great speed, detail, punch, and musicality, all without global feedback. Its moderate gain
structure and low output impedance provides an excellent match with a wide range of
popular power amplifiers.
The new highly shielded power transformer keeps significant e.m.f. fields away from the
audio circuit, yet allows the source of power to be located close to the audio circuit’s
demands, resulting is fast, clear response to audio transients and high resolution of inner
detail. Low noise rectifiers further improve the purity of the DC supplies, thus preserving
both the power and delicacy of the music. Heater voltage is precisely regulated to improve
tube life.
The chassis is rigid and non-magnetic.
A triode MM phono stage or triode MC/MM phono stage are optional.
