R-7HE (2020 version)


(Regenerative power supply)
　

Fully Discrete R-2R Resistor Ladders DAC

Fully Discrete DSD Native decoder

Fully Discrete Real Balance  Current Transmition Design

Support external 10MHz clock input (50 ohm)

The FPGA process data in parallel mode

All Digital Settings accesible By Buttons On Front  (No need  to open the chasis).

Firmware update port assembled on rear, update  firmware no need  to open the chasis.
　

Function introduce :

The front plate before Nov. 2019
        
The front plate since Nov. 2019
        

Setting button :
          Push the "Setting" button one time, the one digit display will blink for active the function setting , push the right "Selector" button can change function . While the display blink, push "Setting" again , the right next one digit display will blink , push the left "Selector" button the left next one digit display will blink .
         While the "Dis" LED blink, push the "Setting" one time , the menu will change to menu page 2.

Left Selector buttons:
           While the display non blink, for select the input sources.
          The 1st of right in the display show 1： AES/EBU digital input.
          The 1st of right in the display show 2： RCA coaxial digital input.
          The 1st of right in the display show 4： Optical digital input.
          The 1st of right in the display show 5： HDMI-IIS digital input.
          The 1st of right in the display show 6： USB digital input.
          (IN3 is the 50 ohm external clock input, setting through the below introduce )
          The external clock input impedance must be 50 ohm, and must match with same impedance external clock generator and cable.

          While the display blink, for the setting digit move one left.

Right Selector buttons:
           While the display non blink, for select the input sources.
          While the display blink, for setting the digital process functions.

Menu Page 1:

Syn  (Internal or External clock selection) :
           I (Internal) ： Select the internal clocks.
         E (External) ： Select the external clock.
         While connect the external clock, the dot of the bottom right corner has light and mean the clock connection had succeed.
         The selection only available while the dot has light, otherwise the display show "Fail" if select the external clock .
　

Pll  (Simulate SAA7220 +TDA1541A sound) :
           t (TDA) : Active simulate SAA7220 +TDA1541A, digital attenuation low to -55DB, was -130DB. Bitwide low to 16bit , was 24 bit. While active this function, I are advice setting to OS2 or OS4 mode. But infact, this function can working with any setting mode.
           r (R-2R) : Disable simulate SAA7220 +TDA1541A .

OS (Oversampling) :
         O (OS) : For select oversampling.
         n (NOS) : For select NOS mode.

Mode ( OS and NOS modes):
          While OS setting on "O" mean the DAC working under oversampling mode, loIr number OS modes sound became warmer and smoother. Or depend on your sense .
         0 : class technology NOS mode.
         2 : 2X oversampling.
         4 : 4X oversampling .
         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. We keep it has 1 to 3 because in future if we update more NOS mode, users don't want replace the MCU.

Di (Display) :
         A (Auto) : Active  the display auto dark, the display will become dark in around 10 seconds after stop operate any buttons .
         n (Non auto) :Disable the display auto dark, the display  light always.

Menu Page 2:

1st number  (reserved) :

2nd number  (reserved) :

Setting examples:

1，Set to most neutral sound mode (8x oversampling, non TDA mode):
           Push the "SETTING" button 2 times, the 2nd digital of the 1st menu blinking, then push the "Right INPUT"  set it to "r" , then push  the "SETTING" button 1 times, ,the 3rd digital blinking, push the "Right INPUT" set it to "O", then push  the "SETTING" button 1 times, ,the 4th digital blinking, push the "Right INPUT" set it to "8".
        
         Thanks to Bill from USA gave us the suggest and samples.

2，Set to TDA1541 Simulate mode:
           Push the "SETTING" button 2 times, the 2nd digital of the 1st menu blinking, then push the "Right INPUT"  set it to "t" ,  then push  the "SETTING" button one times, ,the 3rd digital blinking, push the "Right INPUT" set it to "O" , then push  the "SETTING" button 1 times, the 4th digital blinking, push the "Right INPUT" set it to "0" or "2" or "4" (the number lower sound is more warmer and smoother).
        
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 2 times, the 2nd digital of the 1st menu blinking, then push the "Right INPUT"  set it to "t" , then push  the "SETTING" button 1 times ,the 3rd digital blinking, push the "Right INPUT" set it to "N" .

HDMI definitions : (Compatible with PS audio standard)
Pin 1 :       SDATA -                     
Pin 2 :       GND                         
Pin 3 :       SDATA +                    
Pin 4 :       SCLK +                       
Pin 5 :       GND                         
Pin 6 :       SCLK -
Pin 7 :       LRCK -                        
Pin 8 :       GND                         
Pin 9 :       LRCK +
Pin 10:      NC        
Pin 11:      GND                         
Pin 12:      NC
Pin 13:      NC                            
Pin 14:      NC                           
Pin 15:      NC
Pin 16:      NC                            
Pin 17:      GND                         
Pin 18:      NC
Pin 19:      NC
Even the source has MLCK output but has not effect .

Upgrade Port :
         The DAC can through an USB cable connect betIen computer and "Upgrade Port" to upgrade the firmware for improve the sound quality or performance .