VAC Phi 70 - Manual (Page 18)

16
SPECIFICATIONS
The VAC Phi Seventy has been developed with the critical ear as the major arbiter of quality, with
both conventional and unique measurements providing insight and guidance as necessary. The lack
of emphasis on measurements is due to the fact that engineering's arsenal of equipment and
techniques do not operate on the pattern recognition principals that control human perception of
sound.
In the immortal words of Daniel von Recklinghausen, if it measures good and sounds bad, it is bad.
If it measures bad and sounds good, you've measured the wrong things.
For those concerned with test bench performance, the following describes typical measured
performance when operated at 120 VAC, 60 Hz.
Power Output: 65 watts continuous average power at 1 kHz with less than 2% THD into 4
ohms connected to the 8 ohm tap.
Frequency Response: down 0.5 dB at 7 Hz and 30 kHz, ref 0 dB = 1 watt @ 1 kHz.
down 3.0 dB at 3.5 Hz and 115 kHz, ref 0 dB = 1 watt @ 1 kHz.
Absolute Polarity: Does not invert absolute phase.
FOOTNOTES:
1. Tube Manufacturing at Western Electric: The WE 300, Attila R. Balaton. Journal of the Audio
Engineering Society, Vol.37, No.11, November 1989, pages 949-958.
2. The Low-Loading Self-Biased Amplifier, L.B.Dalzell. Audio, December 1959, pages 19-21.
3. The Fixed-Bias Story (Is Fixed Bias Really Better?), Herbert Ravenswood. Radio-Electronics,
February 1958, pages 47-49.
4. Philips Hi Fi Amplifier Circuits. Published in Holland, 1958.
5. WE 300B. MJ Audio Technology, 1992/5, pages 213-215.