Microwave gives an opportunity to listen favorite music on two different mode. In fact, it represents two types of amplifier in one unit .With power approx. 100W or 40W (on lower mode) in single – ended technique there is a capability to drive almost any type of loudspeaker (with lower or higher sensitivity equally).
Military (N.O.S) GI-7B - output triode tube - represent high technology in vacuum manufacturing as metal-ceramic device. Potential of output tube is 350W of heat dissipation while we use only 60%-65%,further it decrease working temperature point – means additional improvement of amplifiers reliability. Construction of output tube GI-7B is very robust also in mechanical domain – there is no microphonic effect for negative influence to the sound reproduction. Special designed metal-ceramic tube is much lower microphonic then the standard glass bulb type!
For the audiophiles with higher sensitive loudspeaker there is a low mode option (position on rear panel) to lower the output power from 100W (in standard mode) to 40W, also to decrease power consumption of output tube – means no need for extra heat dissipation.
Input and driver tube is also made by military standard indicated like N.O.S. (new old stock) grade.
Hand crafted wide-bandwidth output transformer (custom designed for NAT ) is used in this unit. Output transformer contains no less then 56 separated different material layers. Bandwidth is from 6Hz – 70.000Hz. That is extremly good result for single – ended zero feedback operation mode. Output has separate taps for 4 ohms and 8 ohms speaker load (may drive any load from 1 ohms to over 32 ohms). By specific technical approach mention output transformer in combination with output tube- GI-7B, may drive easy any type of loudspeaker with damping factor equaly as push-pull tube configuration. Zero global feedback concept is well known also as the best solution for purity of sound reproduction. Also without negative influence from wide variety speaker impedance to the amplifier itself – means good for driving all type of speaker equally (electrostatic, dynamic or other types).
Power supply section also speaks for itself. Main transformer is designed for double the power then Microwave consume (approx. 600W) with totally silent operation. There is separate voltage regulators also in zero feedback manner for all amplifier stages including the output one. On such a way sound quality is totally independent from line voltage instability. Equivalent energy from power supply is huge (example for bass response down to 20Hz, it is equal to no less then 8000 Joules of related capacitor type energy). Polypropilene type of capacitors is used for the single output tube high voltage section. Soft start additionally improving reliability of entire amplifier by avoiding voltage stress during turn-on procedure.
There is no need for any adjustment from time to time of output tube's standing current. Electronic circuit automatically adjust current through output tube no matter of time duration – means constant current in time domain – from the brand new to the near end point of tube life.
Quality of electronic material that is used inside Microwave is impressive – beside all military quality tubes there is industrial polypropilene grade capacitors, 0.1% Vishay’s resistors, electrolytic capacitors for 105C of working temperature, last generation of IXYS semiconductors, WBT connectors, pure silver input wiring…
Amplifier works properly at all world wide AC line voltage from 100 – 250 VAC, 50-60Hz (different transformers are used).
|Type||Single Ended Class "A" Triode|
|Power Output||100 Watts @ 1 kHz|
|Frequency Response||6 Hz to 70 kHz -3dB|
|Input impedance||100 k ohms parallel with 100pF|
|Input Sensitivity||2.0V RMS for 100 Watts|
|Gain||23 dB (x14)|
|Rise Time||2.0 microsecond|
|Noise||110 dB below rated output "A" weighted|
|Tube Complement||1 x 6N2P-EV & 1 x GI-7B military type|
|Power Requirement||110 to 240 VAC @ 50 to 60 Hz, 290 VA max. (set in factory)|
|Dimensions||11.8" (300 mm) wide ´ 20.9" (530 mm) deep ´ 10.2" (260 mm) high|
|NET Weight||approx. 79 lbs (36 kg) unpacked / per piece|
|TOTAL Weight||approx. 106 lbs (48 kg) packed in wooden box / per piece|
- Single - Ended pure class A mono block power amplifier
- zero global feedback
- triode based configuration
- short signal path
- DC coupled circuit (only output transformer on signal path)
- military specification power metal-ceramic type triode GI-7B (N.O.S.) output tube
- CE comfortable regarding maximum DC operating voltage
- driver section use 6N2P-EV input tube (N.O.S.) - long life grade
- output transformer custom designed for NAT – 1000W of power
- power transformer custom designed for NAT – 600W of power
- polypropylene capacitors in HV power supply for GI-7B (N.O.S.) output tube
- regulated power supply for all stages (including the output)
- automatic bias current control for the output tube with long term stability
- switch selector for 40W & 100W of power oputput (on the rear panel)
- soft start operate to improve entire reliability
- hand assembled all modulated chassis
- WBT output connectors
- extensively used computer numeric control machines (CNC)
- 0.6" (15mm) thick double aluminum front panel
Specifications are subject of change without notice