R-27  (2021 Version)
Built in real balanced pure class A headamp & preamp
Pure class A power 9000mW@40ohm
Dual gain modes can drive high/low sensitivity headphones

8 group fully discrete R-2R DA modules to combine into real balanced push/pull decoders.

4 group fully discrete real balanced DSD native decoders.

Fully discrete real balanced  current transmition design.

2 pc ultra high frequency 90/98 MHz Accusilicon 318B femtosecond clocks provide synchronous clock for whole unit without PLL up-frequency .

32bit / PCM384K /DSD512 asynchronous transfer Amanero 384 apply the FPGA synchronous clock.

Both USB / HDMI have built in separate isolator and isolate power supply.

The whole digital circuit built with 1 pc FPGA and 5 pc CPLD programmable chipsets to separate the different configured circuits for avoid interrupt, data process in parallel mode.

Support firmware update to improve on sound quality.

All digital process mode settings accessible by buttons on front  (No need  to open the chassis)
Firmware update port accessible on rear (Update  firmware no need  to open the chassis).

  

       
Please note: The product improve cause the inside or outside change without inform .

Please not:
          The unit had built in fully dedicated discrete R-2R resistor ladders DA modules. So it need longer burn in time to achieve the best sound quality and performance.
          Even it had burn in over 100 hours before shipping , but we are advice customers burn in it more than another 500 hours.
          You can power on it with playing music but shut down the volume for quickly finished burn in if you are at home.
          The mini remote shipped without battery because the either DHL and EMS limit shipping by plane , customers want to buy one CR2025 battery and assemble in the remote.



Input mode: 
Push the button "Input" for select the input sources .
Input 1: RCA - SPDIF input.
Input 2: Optical input.
Input 3: HDMI-IIS input.
Input 4: USB input.
Input 5: XLR analog input.
Input 6: RCA analog input.

Gain mode: 
          We have applied wide area volume control system and the new gain technology ,no any switches, relays or parameter of the amp change while change the gain modes so the sound quality is exact same in different gain modes. Users just want to choice the better mode for easy adjust the volume level.
          H mean High gain, and L mean Low gain. The Low gain is 12DB, match with the headphone with over 95DB sensitivity . High gain is 22DB, match with the headphone with less than 95DB sensitivity, even the HE6 , it can be drive fully .
         Below diagram show the volume and gain rate to the output voltage .


Output mode: 
Push the button "OUT", the display will show between " P , H".

"P" mean the unit output from XLR / RCA / ACSS from rear. XLR and RCA can connect to two amps in same time. (If setting the rear outputs on DAC mode, in case it displays "d" instead .

"H" mean the unit output for headphones on front plate.

How to active the digital setting mode:
         While user going to change the setting function, we advice user shut the volume and stop the music source playing.
The function of the "Setting" button:
         Push the "Setting" button one times, the one digital of the display will blinking, the blinking digital mean that can be change the setting.
         While the display blinking, push the "Setting" button again, the next right one digital will blinking, it mean that can be change the setting. While the right first digital blinking and push the "Setting" button again, the display will go into the 2nd setting menu  .
The function of the "Left INPUT" button:
         While the display blinking, push the "Left INPUT" button, the next left one digital will blinking, it mean that can  be change the setting.
The function of the "Right INPUT" button:
         While the display blinking, push the "Right INPUT" button, the blinking digital will change the state, it mean that setting had changed.
         In the setting mode, 5 second later without any button push, the display stop blink and back to the normal display mode. User can start play the music and turn the volume up.

         The below diagram show the two page menus and the functions:

1st page setting menu

1st display : OS/ NOS
         "O" for select oversampling, "N" for select NOS mode.

2nd display : Mode of OS/ NOS
          While OS setting on "O" mean the DAC working under oversampling mode, lower number OS modes sound became warmer and smoother. Or depend on your sense .
         Mode "0" : class technology NOS mode.
         Mode "2" : 2X oversampling.
         Mode "4" : 4X oversampling .
         Mode "8" : 8X oversampling.

         While OS setting on "N" mean the DAC working under NOS mode, it has one mode now, it is the full new NOS configure design.

3rd display : TDA (Simulate SAA7220 +TDA1541A sound) :
           Active (1) : Simulate TDA1541A sounding,  While active this function, and set toOS0 or OS2 or OS4 mode, simulate SAA7220+TDA1541A sounding . In fact, this function can working with any setting mode and bring the different sound flavor.

4th display : Gain
           H mean High gain, and L mean Low gain. The Low gain is 12DB, match with the headphone with over 95DB sensitivity . High gain is 22DB, match with the headphone with less than 95DB sensitivity, even the HE6 , it can be drive fully .

2nd page setting menu

1st display : DAC/PRE (Select the rear output state)
           "d" mean the XLR/RCA/ACSS outputs on rear set to DAC mode, in case the volume control had disable. (The headphone output always has volume control ).
           'P" mean the XLR/RCA/ACSS outputs on rear set to preamp mode, the volume control available.

2nd display : Dark
         Active (1)  the display auto dark, the display will become dark in around 10 seconds after stop operate any buttons . Disable (0) the display auto dark, the display  light always.

3rd display :  Reserved

4th display :  Remote
          This is mean the remote function setting, if it set to 0, whether long or short push the remote controller volume button, the unit volume only change 1 step . If set to 1, push and hold the remote controller volume button, the unit volume change continuously .In case if set to 1 but the unit had control by other devices , set to 0 please.

Setting examples:

1，Set to most neutral sound mode (8x oversampling, non TDA mode):
           Push the "SETTING" button one times, the 1st digital of the 1st menu blinking, then push the "Right INPUT"  set it to "0" , then push  the "SETTING" button one times, ,the 2nd digital blinking, push the "Right INPUT" set it to "8", then push  the "SETTING" button one times, ,the 3rd digital blinking, push the "Right INPUT" set it to "0" .
2，Set to TDA1541 Simulate mode:
           Push the "SETTING" button one times, the 1st digital of the 1st menu blinking, then push the "Right INPUT"  set it to "0" , then push  the "SETTING" button one times, the 2nd digital blinking, push the "Right INPUT" set it to "0" or "2" or "4" (the number lower sound is more warmer and smoother), then push  the "SETTING" button one times, ,the 3rd digital blinking, push the "Right INPUT" set it to "1" .
3，Set to NOS mode (New configure NOS mode with simulate TDA mode for the one of the most warm and smooth sounding):
           Push the "SETTING" button one times, the 1st digital of the 1st menu blinking, then push the "Right INPUT"  set it to "N" , then push  the "SETTING" button two times ,the 3rd digital blinking, push the "Right INPUT" set it to "1" .
4，Set to High Gain mode:
           Push the "SETTING" button one times, the 4th digital blinking, then push the "Right INPUT" button set to "H" .

5，Set to DAC output mode :
           Push the "SETTING" button one times, the 4th digital blinking, then push the "SETTING" button one times, the 1st digital of the 2nd menu blinking, push the "Right INPUT" set to "d".

6，Set to remote volume continued control mode:
           Push the "SETTING" button one times, the 1st digital of the 1st menu blinking, then push the "Left INPUT" button one times, the 4th digital of the 2nd menu blinking, push the "Right INPUT" button set to "1".

       
HDMI definitions :  (Apply HDMI transmit the IIS signal, the pin's definitions must exact same , and not promise compatible with other brands)

This product don't need the source MCLK signal but even the source has MLCK output but has not effect .

Firmware update introduce:

        

UPDATE PORT 10 pins port :
       To connect the Altera Blaster and proceed with an FPGA firmware update from Windows, using the Altera programming software. These updates are meant for upgrading the functionality and/or sound quality .
FPGA firmware download and update guide: http://www.audio-gd.com/Firmwaredownload.htm
UPDATE PORT switch :
        For updating the built-in Amanero module's firmware through the USB input.
        Please note: If no plan to update the Amanero firmware, don't touch this switch when the product is power on .
Amanero firmware download and update guide: https://www.amanero.com/combo384_firmware.htm
Amanero firmware update guide : http://www.audio-gd.com/Pro/dac/Amanero/AmaneroEN.htm
        Please download the update tool and guide from Amanero's official web . In the official update guide, there is a step requiring that two pads be shorted more than 1 second on the Amanero module , in this product, users only need to push the red button for more than 1 second in order to perform the same step . Other update steps are the exact same as in the official guide.