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 .


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 .



ysa150mk3in.jpg (782074 個位元組) Dual mono power supply ( this is equal one pair mono block build-in one chassis )

ysa150mk3choke.jpg (545694 個位元組)  Hashimoto special grade choke

  ysa150mk3in2.jpg (463741 個位元組) The coupling cap use Miflex KFPM copper foil polypropylene film caps

realxlout.jpg (707814 個位元組) Hasimoto special grade CUT CORE orient high B output transformer.

Review by HiFi review #429

ysa150mk3b.jpg (538466 個位元組) ysa150mk3c.jpg (482473 個位元組) ysa150mk3d.jpg (484044 個位元組) ysa150mk3d2.jpg (480657 個位元組) ysa150mk3g.jpg (549779 個位元組)

  ysa150mk3h.jpg (427668 個位元組) ysa150mk3f.jpg (471143 個位元組) ysa150mk3i.jpg (694840 個位元組) ysa150mk3j.jpg (620875 個位元組)  

YSA150S-MK3 Reference-X use KT170

ysa150skt170.jpg (446674 個位元組) ysa150skt170a.jpg (540123 個位元組)



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)



Room1308, 13/F,BLK C,.  
Kai Tak FTY BLDG.   
99-101 King Fuk ST,.   
San Po Kong,   KLN,.
Hong Kong
E-mail : info@ys-audio.com 
WhatsApp: 93440168   
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