Inovative Audio Manufacture

Se1 HPS Single - Ended Mono Block Power Amplifier

After 24 years from the first production (from 1999.) of Se1, newest version Se1 HPS  rapidly improve quality of all previous models! Power output is set to max. 60W (instead of 25W from previous Se1 GM70 model). Special single voltage gain stage design is implemented. Single-Ended Mono Block Power Amplifier Se1 HPS (Hybrid Power Supply) has very short direct signal path - without main coupling passive components - no any coupling capacitors & no any inter-stage transformer(s).

One part of input stage in Se1 HPS form 6N6P (or equivalent) - very linear tube capable to act as low distortion device, made by military standard, indicate as N.O.S. (New Old Stock) grade of the highest quality.

Direct-heated triode (D.H.T) GM70 is used as output stage. It is a high performance output tube capable to dissipate up to 125W of heat, made by military grade as well. Se1 HPS represent a truly single-ended design without parallel connection of output tubes.

Specially designed output transformer supported wide frequency transfer as well as perfect symmetry for both 4 ohms and 8 ohms connections.

Frequency response of Se1 HPS is very linear without any sub-resonance region.

Tonal quality is independent from line voltage fluctuation as there is regulated power supply for HV (High Voltage) for all stages as well as for the filament supply.

Se1 HPS may easy drive any medium to high sensitively loudspeaker to bring great sonic pleasure that only real D.H.T. (Direct Heated Triode) single - ended amplifiers can do.

Quality of electronic components that is used inside Se1 HPS are of the highest level - military grade and N.O.S. tubes, Vishay 0.1% resistors, military grade graphite power resistors, electrolytic capacitors for 105C of operating temperature, last generation of  semiconductors devices, laboratory grade output connectors, silver-ofc input wiring...

Se1 HPS works properly at world wide AC line voltage from 100-260 VAC, 50-60 Hz (set in factory only).

NOTE: -Standard version is used pseudo-balanced input
          -First step of upgrade : pure-balanced input is realized with hand wound nano-crystalline core transformer
          -Premium step of upgrade : pure-balanced input is realized with hand wound silver-ofc wired nano-crystalline core transformer

 NOTE: Protect covers should always be placed over output (big) tubes due to safety!

Technical Specification
Name Value
Type Single Ended Class "A"

Power Output


up to 60 W @ 1 kHz @ 4 ohms or 8 ohms taps

0.09% @ 1 W, 0,32% @ 20 W @ 1 kHz @ 4 ohms or 8 ohms taps

Frequency Response 10 Hz to 70 kHz
Input Impedance 100 kohms parallel with 470pF
Input Sensitivity 1 V RMS for max. 60 W @ zero global feedback
Gain 27 dB (x22)
Noise 108 dB below rated output "A" weighted
Tube Complement 1 x 6N6P, & 1 x GM70 (2 tubes/block)
Power Requirement 200 to 260 (100 to 130) VAC @ 50 to 60 Hz, 200 VA max.
Dimensions 11.8" (300 mm) wide x 22.6" (575 mm) deep x 11.5" (385 mm) high
NET Weight approx. 64 lbs. (29 kg) unpacked / monoblock
TOTAL Weight approx. 190 lbs. (86 kg) packed in two flight case as option

Design Features

- single-ended type
- short signal path (unique circuit by NAT)
- mono block pure class "A"
- Direct Heated Triode (D.H.T.) output tube - high power GM70 tube (military grade, N.O.S.)
- triode tube 6N6P (military grade, N.O.S.) is used in input and driver signal path
- zero global feedback with ultra low feedback as option
- no coupling capacitor from input to output
- no inter-stage transformer from input to output
- wide bandwidth output transformer (custom design for NAT)
- regulated power supply for all stages (that include HV and filament for both type of tubes)
- soft start filament operate to improve long term stability
- hand assembled all modulated chassis
- aluminium front panel of 10mm thick
- high mass laboratory grade output connectors
- gold plated PTFE insulated RCA input connector custom ordered from NAT
- extensively used computer numeric control machines (CNC)
- glass cover cage (optional)

Specifications are subject of change without notice