Page 9
VAC SIGMA PREAMPLIFIER SPECIFICATIONS (typical)
Type:
Vacuum tube line stage with home theater (direct power
amplifier) mode.
Options:
Remote control for volume & mute
Dedicated MM phono input
Dedicated MC phono input
Line stage preamplifier
:
Gain:
24 dB
Maximum input signal:
Essentially infinite (attenuation precedes line stage)
Main output:
Inverting to RCA
Pin 2 positive “hot” on XLR, pin 3 negative
Tape output:
Unity gain from selector, non-inverting (archival correct)
Phono stage preamplifier (optional)
:
Gain:
40 dB MM, 60 dB MC (measured at tape output)
Residual noise:
3 mV at output (S/N ratio approx. 69 dB MM)
Overload:
117 mV @ 1 kHz = 8 volts RMS output, MM
460 mV @ 10 kHz, MM
Frequency response:
RIAA +/- .25 dB
Notes:
Does not invert absolute phase.
Tube compliment
:
3 x 12AX7 (phono option) (located on circuit board at left side of chassis)
2 x 12AU7/6189A (line stage)
2 x 12AX7 (line stage)
