Se1

Single Ended Mono Block Power Amplifier

Download Single Ended Triode Ampifier Survey (357 kB, PDF Format) written by Mr. Scot Markwell and read his impressions about Se1. Review was published in AVguide in June 2003.

MkII version already improve quality of previous model by increasing power to 35W with special driver, super tube 6N30P-DR(military grade).

Single Ended Mono Block Power Amplifier Se1 has very short signal path without passive components. It means that this circuit contains no coupling capacitors & no inter-stage transformers. Specially designed hand wounded output transformers improve frequency bandwidth, over standard construction.

Frequency response of our Mono Blocks Se 1 from 9 Hz to 60 kHz is extremely  linear without any subresonance region.

Se1 has automatic bias circuit means current trough output tube(211) is always the same. There is no need for any type of adjustment.

Sound quality is totally independent against power supply instability, because all stages in amplifier have stabilisation.

These Mono Blocks require sensitively loudspeaker (over 90dB / 2.83V / 1m @ 8 ohms), but with some of the single ended "friendly" loudspeaker Se 1 will bring you great sonic pleasure that only real single ended triode virtues can do.

NAT Audio has review for Plasma Line Stage and Se1 Mono Block Power Amplifier in Netherlands audio magazine "Music Emotion" nov/dec 2006. edition.

Click here to download original review (Dutch) (454 kB)

Click here to download review (English) (390 kB)

Technical Specification

Type

Single Ended Class "A"

Power Output

35 Watts @ 1 kHz 8 ohms taps

Frequency Response

5 Hz to 50 kHz @ 8 ohms taps

Input Impedance

100 kohms parallel with 100pF

Input Sensitivity

1 V RMS for 35 Watts Output @ zero feedback

   

Rise Time

5.0 microseconds

Noise

108 dB below rated output "A" weighted

Tube Complement

1 x 6N2P-EV, 1 x 6N30P-DR & 1 x 211 per block

Power Requirement

220 to 240(110 to 120) VAC @ 50 to 60 Hz, 180 VA max.

Dimensions

11.8" (300 mm) wide x 20.4" (520 mm) deep x 10.2" (260 mm) high

NET Weight approx. 60 lbs. (25 kg) unpacked / per piece
TOTAL Weight approx. 154 lbs. (70 kg) packed in two wooden box

Design Features

- single ended type
- mono block concept
- absolute zero feedback with ultra low feedback option
- pure class "A"
- all triode configuration
- short signal path
- no coupling capacitor from input to output
- no interstage transformer
- direct heated 211 triode output tube
- absolute zero feedback or ultra low feedback option
- hand wound output transformer (custom design for NAT)
- torodial low density power transformer (custom design for NAT)
- regulated power supply for all stages
- automatic bias control for output tubes
- soft start operate to improve long term stability
- WBT output connectors
- hand assembled all aluminum modulated chassis
- 10mm thick aluminum front panel (standard black finish, optional silver)
- extensively used computer numeric control machines (CNC)


Specifications are subject of change without notice