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iscrete Preamp / Headphone amp
Applied Diamond Difference design
Power output 10,000 mW @ 40 ohm

Price:   USD525
Extra metal remote :  USD50        

The free remote control without warranty.


Summarize Use Manual Specs Technology Detail Custom Option Shipping Cost

Feeback:      http://www.head-fi.org/t/617667/audio-gd-sa-31-head-amp-preamp-a-powerfull-head-amp-with-diamond-difference-design/15

What's new on the SA-31SE:
1, Boost the gain from 10DB (SA-31)  to 20DB (High gain model on SA-31SE), even with low output level sources ( like 1.5VRMS), still have enough gain and power for drive the HE6 and low sensitivity headphones.
2, For the high sensitivity headphone and preamp output model , we have redesign the new exponential volume control board built in 14 pcs relays (SA-31 only had 8 pcs), it have 100 steps and 100DB level control range, allow users  very fine to adjust the volume.
The below picture show the volume characteristic , green is with the SA-31, red is with the SA-31SE .

3, Redesign the control software, users can quite quickly continuous adjust the volume on front panel, from volume 0 to volume 50, only need around 5 seconds.
4, Built in OCC wires .

Fully  discrete Diamond Difference design , without any OPA and couple caps in the signal channels. High working voltage (+/-35VDC) class A design .
R-core transformers. 
More than 25,000uf audio grade NOVER capacitors are used to ensure ample and smooth power feed.

 For larger power drive, the output stage applied two pair 15A / 150W Toshiba transistors , power output 10,000mW @ 40 ohm, no matter for most headphone in world.
2 group class A dedicated PSUs are used to purify the power supply, the amp working at high idle class A model .
Digitally controlled relay-based volume control to avoid channel imbalance and improve sound quality. SA-31 has 100 steps volume level control in both high gain mode and low gain mode. The total 200 step volume control ensures smooth control of the volume level.
5 Channel RCA inputs
Preamp output :
  RCA * 3
Headphone output : 4 pins XLR / 6.3MM SE (10W @ 40 ohm)
 (The XLR  still single-ended output, just for who have balanced plugs headphone but use with the SA-31 )
Memorizes all settings and it could resume the last settings when power on.
Applied high end grade parts , like DALE resistors, EVOX caps (Germany) and  the Neutrik sockets

The SA-31 remote control common with other audio-gd DAC remote control, if customer already own the audio-gd brand DAC remote control and want the especial remote control for SA-31, please inform us while place the order.

Sound Characteristics: 
We describing its retains rich details and high clarity with its abundant music flavor with wide and deep sound stage .

History of the Diamond Difference design :

         At July 2004, I registered the brand audio-gd ,  at September 2004, I published the first generation diamond difference design at the < Radio & TV > , the best popular  audio technology magazine in China .There were a lot DIYer call me even writed letters to me discuss the circuit.          At November 2004 , the fist regular product of audio-gd , XA-100 power amp released. It had the good honor from customers , let audio-gd can stand and grow up.Before this amp, I already have 6 years experiences of built the Diamond Difference circuit .         At 2005,  the first regular DAC product DAC-1 released,  a   TDA1541A with diamond difference output stages.
       At 2006 ,the RT-1 (Replace Tube)  released ,  its sound adjusted based on a 300B tube amp.      At 2007 , the RT3 kit released for DIYers .         At 2008 , the DAC-3 released, built in 4 pcs PCM1704 with diamond difference design .
At 2009 ,the SA-300 balanced amp released .     At 2010, I design the dual TDA1541AS2 DAC for fun, we only sale 5 units to the return customers . A pair TDA1541AS2 now value USD800 in market . At 2011 is the Reference 8 and 9 released .

Some other products applied Diamond Difference design maybe can't list , like the C-2 SA, ROC-SA, SA-100.



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