YSA300B Reference 9W x2  SET Stereo Valve Tube Power Amplifier


Audio Experience YSA300B Reference is a SE 9W x 2 Stereo Valve Tube Power Amplifier.
   The power amplifier use one 300B power tubes work at Class A Single Ended Triode no negative feedback configuration status to provide 9W adequate output . Moreover, It use the high quality output transformer ( Hasimoto . made in Japan).

   The 5687WB input tube use Miflex KPCU ( Copper foil Poly/Paper in Oil) coupling cap to 5687WB driver tube to driver Hasimoto A-105 Interstage transformer, This new design driver stage got the wide frequency range and very good sound. The interstage transformer direct coupling to 300B power tube. The 300B tube work at Class A Single Ended Triode mode to driver Hasimoto H-20-3.5U high quality output transformer , The Hasimoto H-20-3.5U CUT CORE orient high B output transformer has very low Insertion Loss 0.3dB only.  ( Many SET tube power amplifier in Hi-End audio market , Their have the output transformers is over 2dB 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. 

    This power amplifier case structure and parts arrangement are perfect, the signal path is directly and shortly connected. Great heat dissipation, an anti-shock and anti-RF function to guarantee it works at a very stable status. For sure, this machine is produced by point-to-point methodology. 




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ysa300brefe7.jpg (372373 個位元組)  ysa300brefein.jpg (475837 個位元組)  ysa300brefe1b.jpg (507887 個位元組)  

h20.jpg (144084 個位元組) Hasimoto H-20-3.5U Output Transformer


a-105.jpg (466866 個位元組) Hasimoto A-105 CUT CORE orient high B Interstage Transformer


ysa300brefein2.jpg (448366 個位元組) Miflex KPCU ( Copper foil Poly/Paper in Oil)  



Output and T.H.D :  
1W per channel , 1kHz total harmonic distortion typically 1% 
9W per channel , 1kHz total harmonic distortion typically 5%  (rated output)

Input :  RCA 

Input Impedance : 100K ohm

Frequency Response:

Test at 1W  20Hz ~ 58kHz  (20Hz -1.8dB, 20kHz -0dB, 58KHz -3dB)
Test at 9W  20Hz ~ 58kHz  (20Hz -3dB, 20kHz -0dB, 58KHz -3dB)

Input Sensitivity :  0.36V / 9W (rated output)     27dB gain ( test at 8 ohm )

Output impedance : 4 ohm, 8 ohm , 16 ohm

Noise: Less than 1.5mV
Phase Mode : Normal

Construction: Copper and High quality aluminum

Tubes Required: 5687WB x2 , 300B x 2, 5U4Gx 1

Dimension: 430mm x 340mm x 230mm (W x D x H)

Total Weight: 19.5kg

Power Source: 110-117/220-240V,50/60Hz (for order)


Actual Price: HK$28,300

The output transformer from H-20-3.5U upgrade to use H-30-3.5S  add extra cost $3000.




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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