YSA150S-MK3 Reference stereo power amplifier

YSA150S-MK3 Reference-X 150W + 150W Stereo Valve Tube Power Amplifier (Since: August 2020)

Audio Experience YSA150S-MK3 Reference-X is a 150W + 150W Stereo Valve Tube Power Amplifier.

It uses two matched pair of Gold Lion KT88 ( KT120, KT150, KT170 )power tubes and UL working status to provide RMS 150W adequate output for most of the Hi-End Speakers to ideal performance. Moreover, It use the high quality output transformer ( Hasimoto . made in Japan).
Dual mono power supply design ( It is same one pair mono block build in at one chassis )
Huge dynamic range, both the beautiful tone color and wonderful rhythm , ultra linear circuit of the valve tubs power amplifier designed for the SACD source in the New Century. uncanny natural flowing heart-stirring sound that matches any other ultra-Fi products on the market .

Features

The new design input stage is 12AU7 direct coupling to 5687WB driver stage to 6H30 cathode follow driver stage , The driver stage uses coupling cap to KT88 power tube , The KT88 ( KT120, KT150, KT170 ) work at Class AB1 UL P-P mode to driver Hasimoto output transformer , The Hasimoto special grade CUT CORE orient high B output transformer has very low Insertion Loss 0.15dB only. ( Many tube power amplifier in Hi-End audio market , Their have the output transformers is over 1dB Insertion Loss . only about 10% very high price tube amplifier use under 1dB Insertion Loss of output transformer ) . The output transformer has low insertion loss is very important , the best of the best is 0 dB Insertion Loss , The output transformers for High End tube amplifier need under 1dB Insertion Loss . The Insertion Loss over 1.5dB output transformer will lost many low level music.

The components , NFB value , tube type , circuit all select by listen and instrument test .

The two power transformer is R-Core transformer.
The output transformer is Hashimoto special grade CUT CORE orient high B output transformer , made in Japan
Two Choke are Hashimoto special grade choke for each CH , made in Japan
Dual mono power supply ( It is same one pair mono block build in at one chassis )
Power supply use F&T power caps
All coupling cap use Miflex KFPM copper foil polypropylene film caps
The inside wire have uses IN-AKUSTIK cable.

Dual mono power supply ( this is equal one pair mono block build-in one chassis )

Hashimoto special grade choke

The coupling cap use Miflex KFPM copper foil polypropylene film caps

Hasimoto special grade CUT CORE orient high B output transformer.

Review by HiFi review #429

YSA150S-MK3 Reference-X use KT170

Specifications

Controls
Power On/Of

Output and T.H.D :
1W , 1kHz total harmonic distortion typically 0.06% (20Hz 0.07%, 20KHz 0.08%)
150W 1kHz total harmonic distortion typically 1.9% (30Hz 3%, 20KHz 2.5%)(rated output)

Max: 210W ( each CH )

Input : RCA

Input Impedance : 100K ohm

Frequency Response:

1W 20Hz ~ 100KHz ( 20Hz 0dB, 100KHZ 0dB)
160W 20Hz ~ 100kHz (20Hz -1dB , 100kHz -2.6dB)

Input Sensitivity: 1.65V RMS rated output (150W) 28.5dB Gain ( Test at 8 ohm )

Output Taps: 16 ohm ,8 ohms, 4 ohms.

Noise: Less than 0.5mV

Damping factor : approximately over 33

Phase Mode : Normal

Tubes Required : (8) two matched pair KT88 Power Output ( or KT120, KT150, KT170 ) , ( 2 ) 6H30 Driver, ( 2 ) 5687WB Driver , ( 2 )12AU7 Input .

Dimension: 433mm x 460mm x 233mm (W x D x H)

Total Weight: 33kg

Power Source: 220-230V,50/60Hz

Actual Price: HK$48000

Add extra fee HK$2500 for the amplifier with Tung-Sol KT150 power tubes.

Add extra fee HK$4500 for the amplifier with Tung-Sol KT170 power tubes.

Add extra fee HK$2500 for the amplifier add Balanced input with Jensen input transformer (both with Balanced and RCA input)

YS-Audio
Room1308, 13/F,BLK C,.
Kai Tak FTY BLDG.
99-101 King Fuk ST,.
San Po Kong,   KLN,.
Hong Kong
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