Transmitter
Single Ended Mono Block Power Amplifier
Transmitter is a new reference point power amplifier made by NAT as pure class A, single – ended type with zero global feedback circuit configuration.
Transmitter gives an opportunity to listening the sound on two different mode as high power setting to 120W or moderate setting to 40W, both of pure direct heated triode type. With power of 120W in single – ended configuration there is a capability to drive almost any type of loudspeaker.
Philips (or equivalent) QB5/1750 type as output device represent high technology in vacuum tube manufacturing. Potential of output tube reach 565W of heat dissipation! Transmitter used only half of max. dissipation that significantly decrease working temperature point for further reliability improvement. Construction of output tube is very robust in mechanical domain resultated in non-microphonic sound reproduction. Special designed pure non-magnetic pipe type cover cage additionally improved negative vibration effect from the environment, correlate to further increase micro detail in sound reproduction. For the audiophiles with sensitive loudspeaker Transmitter offer low mode option to lower the output power from 120W (in high mode) to 40W. Further it decreased power consumption of output tube that resulting to lower heat dissipation.
Input and driver tubes (6N1P-VI and 6N6P/6N30P) are made by military standard, indicated as N.O.S. (new old stock) grade of the highest quality.
Hand crafted wide-bandwidth output transformer (custom designed for NAT ) is used in Transmitter. Output transformer is constructed with no less then 61 separated different layers. Bandwidth reach 8Hz – 100.000Hz as exceptional good flatness for single – ended zero feedback amplifier. Output taps for 4 ohms and 8 ohms speaker load are realized with laboratory grade connectors. NOTE: Transmitter may drive any load from 1.5 ohms to over 32 ohms. By specific technical approach output transformer in combination with output tube may drive easy any type of loudspeaker with damping factor equally as in push-pull configuration. Zero global feedback concept is the best solution for purity of sound reproduction without negative influence from wide variety of speaker impedance. Transmitter may drive all type of speaker equally (electrostatic, magnetostatic, dynamic or other types).
Power supply section participate in sound quality almost as amplifiers main circuit. Silent power transformer is designed for double the power then Transmitter consume. There is a separate voltage regulators in zero feedback manner for all amplifier stages including the output one. Tonal quality is independent from line voltage fluctation. Equivalent available energy from power supply is huge, equal to no less then 8000 Joules (8kJ) of energy. Soft start additionally improve Transmitter reliability by avoiding high voltage stress during turn-on procedure.
No any adjustment of output tubes standing current is necessary. Automatic electronic circuit adjust current through mighty QB5/1750 tube no matter of tube duration – means constant current in time domain – from the brand new to the end point of tube life.
Quality of electronic components that is used inside Transmitter are at high level – PTFE and “in-oil” military grade capacitors, Ohmite HV resistors, Caddock resistors, Vishay 0.1% resistors, electrolytic capacitors for 105C of operating temperature, last generation of IXYS semiconductors, Schutzinger laboratory grade connectors, pure silver input wiring…
Transmitter works properly at world wide AC line voltage from 100 – 250 VAC, 50-60Hz (different voltages set in factory only).
NOTE: -Standard version use pseudo-balanced input
-First step of upgrade : pure-balanced input realised with hand wound nano-crystalline core transformer
-Premium step of upgrade : pure-balanced input realised with hand wound silver-ofc wired nano-crystalline core transformer
Technical Specification
Name Value
Type Single Ended Class “A” Triode
Power Output max. 120 Watts @ 1 kHz
Frequency Response 8 Hz to 100 kHz -3dB
Input impedance 100 k ohms parallel with 100pF
Input Sensitivity 1.5 V RMS for 100 Watts
Gain 25.50 dB (x18.8)
Rise Time 3.0 microsecond
Noise 110 dB below rated output “A” weighted
Tube Complement 1 x 6N1P-EV, 1 x 6N6P/6N30P, 1 x QB5/1750
Power Requirement 110 to 240 VAC @ 50 to 60 Hz, 550 VA max. (set in factory)
Dimensions 11.8″ (300 mm) wide ´ 20.9″ (530 mm) deep ´ 10.2″ (260 mm) high
NET Weight approx. 89 lbs (40 kg) unpacked / per block
TOTAL Weight approx. 220 lbs (100 kg) packed in polypropylene crate / per pair
Design Features
– single-ended pure class A mono block power amplifier
– zero global feedback
– all triode configuration
– short signal path
– no inter-stage transformer
– output section-direct heated triode connected type Philips (or other western manufacturer equivalent) QB5/1750 (N.O.S.) output tube
– driver section – 6N1P-EV & 6N6P/6N30P tubes by military grade and (N.O.S.) – long life grade
– hand wound output transformer (custom designed for NAT)
– hand wound with silent operation power transformer (custom designed for NAT)
– additional polypropylene capacitors in power supply for output tube
– regulated power supply for all stages (including the output one)
– automatic bias current control for the output tube with long term stability
– soft start operate to improve reliability
– hand assembled all modulated chassis
– high mass Schutzinger laboratory grade output connectors
– gold plated PTFE insulated RCA input connector custom ordered from NAT
– extensively used computer numeric control machines (CNC)
– 4/5″ (20mm) thick quadruple aluminum front panel
– cover cage (optional)
Specifications are subject of change without notice
