Instruction Manual

13
SPECIFICATIONS
The VAC Renaissance Seventy/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 with no feedback (0 dB) 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 4-8 ohm tap.
Distortion:0.12 % THD at 10 watts.
Frequency Response:down 0.5 dB at 6 Hz and 90 kHz, ref 0 dB = 1 watt @ 1 kHz.
down 3.0 dB at 2 Hz and 103 kHz, ref 0 dB = 1 watt @ 1 kHz.
Power Bandwidth:down 0.5 dB at 12 Hz and 58 kHz.
down 3.0 dB at 8 Hz and 85 kHz.
Negative Feedback:Selectable: 0, 3.5, 4.5, 5.5, 6.5, 7.5 dB.
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.