Wisdom in mind,   enthusiasm at heart.

NFB-10.33
Discrete  DAC+ Headphone amplifier / Preamplifier

32bit / 384K Asynchronous Transfer  USB-32 Chip
Built in 2 Pieces Hi-end grade WM8741 Chips

The rule of the power ON /  OFF ( in Preamp model connect to power amp ):
Power On :
     Source power ON ---->    NFB-10 power ON ----> Amp power ON
Power Off:
    Amp power OFF ---->  NFB-10 power OFF   ---> Source power OFF .
In USB model, start the computer then power on the NFB-10 is necessary because the NFB-10 have not applied the USB+5V for less interrupt from the computer.

Setting the NFB-10.33 have I2S input:
         If your don't need the NFB-10.33 have USB input, you can change to I2S input .
             1, Please pull out the power cord before the cover of the chassis is taken off .
             2, Take off the two screws on rear and take off the USB module.
             3, The I2S input socket defines as the photo.

How to set the NFB-10.33 DAC output in “variable line level” mode or “fixed line level” mode?
         NFB-10.33 has dedicated DAC output in RCA, XLR and ACSS. In default, its output level mode is set to “variable line level” (If your amplifier or active speaker has no volume control, we advise to set it to “variable line level”). If users would like to switch to “fixed line level” mode, please push a jumper into the socket as illustrated in the following photo.
         The jumper is pushed into the socket labeled in the red pane for “fixed line level” mode. (Please pull out the power cord before the cover of the chassis is taken off)      

If only the RCA or 6.3MM headphone  is used, is the NFB-10.33 being wasted or not fully utilized?
       NFB-10.33 is a real balanced DAC . It has balanced output (ACSS, XLR and balanced headphone output) and single-ended output . There are 4 ACSS amplifiers in the NFB-10.33 for balanced outputs and balanced inputs. Even when a single-ended output is used, the ES9018 DA chips will perform fully thanks to the fully balanced design.

Please note :
        Before shipping we had double check the gear have the perfect state of the outside . 
        Few countries customs workers is rude , maybe scrape the chassis or volume knob while custom check , if the scrape have not effect the performance , customers can pay the shipping cost for ask we send the free parts for replacement while got the goods .
        If the volume switch broken during rude custom check , there is a spare volume switch in the pack for customers replace by themselves .
        In our experiences , scrape chassis or shatter the volume switch is very infrequent ( In case less than 1%).

DAC/HP button:
Select the output modes.
         H:   Headphone output.
         P:   Preamplifier output. 
         Users can choose between “variable line level” and “fixed line level” mode in Preamplifier output. In “fixed line level” mode, NFB-10.33 becomes a  Fully Balanced Dedicated DAC; In “variable line level” mode, NFB-10.33 becomes a Fully Balanced Dedicated DAC + Fully Balanced Preamplifier.
　

Gain button:
Select the high / low gain mode.
        H: High gain mode at +12dB.    
        L: Low gain mode at 0dB.
　

Selector button:
Select the input sources.   
        1: USB input.
        2: Optical input.
        3 : Coaxial RCA / BNC input. ( The BNC and RCA coaxial input only can connect either simultaneous .)

Volume knob:
        Turn Left :     Reduce the volume.
        Turn Right  : Increase the volume .
        Because different sources may have different output level, so before select the input sources, reduce the volume is more safe .