VAC Phi "Kappa 30i" User Manual
Page 4
3
INTRODUCTION
The Phi Kappa is the world's finest integrated amplifier and an absolutely unique component.
Its unusual topology, premium parts, and flexibility make it a pleasure to hear and operate.
Essentially, the Kappa is the combination of elements of the Phi 2.0 preamplifier with the Phi
30/30 stereo amplifier into a single, integrated, optimized system.
The phono stage uses triode tubes operating without loop feedback. Gain is moderately
high, with a very low noise floor. Low output MC cartridges are accommodated by means
of high quality matching transformers, which contribute voltage gain without noise, resulting
in detail that emerges from a remarkably dark and neutral background.
Remote volume control is implemented via a motorized mechanical device. This provides
two major advantages. First, the control is completely intuitive to use. Second, we avoid the
sound degradation attendant with VCAs, transistor switches, and switched resistor arrays.
The power amplifier section uses four 300B tubes in Class A1. These operate in self-bias mode; no
user adjustment is required. Each is provided with a separate DC filament supply to ensure that no
undesirable couplings occur; only the intended ideal signal path exists. The input circuitry is
derivative of the unique Williamson circuit, which provides pure, direct coupled, inherently balanced
input amplification and phase splitting. Type 6SN7/5692 octal twin triodes do the honors.
Two superb VAC output transformers allow high power to be delivered with sonic purity, provide
superb voltage/current translation, and will drive impedances from eight ohms to as low as one ohm.
The main chassis is machined from thick aluminum. The separate power supply allows e.m.f.
fields, switching transients, and mechanical vibration to be isolated from the audio circuits.
The high voltage supply dual choke pi filtering for extremely low noise.
The Phi Kappa is designed not to the latest fad but to substance, for the highest possible
sound quality. Time spent familiarizing yourself with this manual will be well rewarded.