NAT Symmetrical Balance Tube Pre-Amplifier. The unit is in good condition, unfortunately there is a ding on the faceplate which automatically lowers the condition to a 7 (see pictures). Voltage is set for 120 Vac (standard in the US and Canada). We have checked with the manufacturer and the unit is 9 years old. There is no serial number on the unit, but the manufacturer could tell the age from a few pictures of the inside.
Note this unit is the "Symmetrical New". We did not want to put "New" in the title to confuse with being a brand "new" unit.
NAT Audio introduced tube balanced preamplifier called "Symmetrical New". New line stage is completely in dual mono topology also with zero feedback all triode vacuum tube design.
There are twelve(12) tubes that works in perfect symmetry, means six(6) per each channel.
Design based on fact that preamplifier may work perfect in both type of operation-balanced (xlr) and single ended (rca).
Also, attenuation network is realized with 56 high reliability silver contact relay. Only one (vishay) resistor is always to the signal path (shunt type)!
"Symmetrical" may drive any known power amplifier no matter of type or internal impedance (compatible with input impedance of 600ohms). It also means that interconnect length between pre and power amplifier may be of enormous value.
Remote control as standard option is made from solid block of aluminum.
Frequency Response 0.07 Hz to 300 kHz – 3 dB ; 20 Hz to 20 kHz ± 0.01 dB
Noise < -95 dB "A" weighted @ 1V rms
Gain 15.5 dB (X 5.6 Phase status: non-inverted (0 degree)
THD & N < 0.03 % 20 Hz to 20kHz @ 1V rms
Input Impedance > 10 kohms single ended: >20 kohms balanced
Stereo Separation > 100 dB @ 1 kHz
Tube Complement 2 X OA 2, 2 X PY88, 2 X 6N1P-EV, 2 X 6N2P-EV & 4 X 6N6P-I
Output Impedance < 70 ohms on single ended ; <140 ohms on balanced
Power Requirements 110 VAC or 220 VAC @ 50 to 60 Hz, max. 100 VA
Dimensions 19" (483 mm) wide ´ 18" (455 mm) deep ´ 6.5" (165 mm) high (max.dimensions)
NET Weight approx. 60 lb. (27 kg) unpacked
TOTAL Weight approx. 77,2 lb. (35 kg) packed in wooden box
Please let us know if you have any further questions.