Wisdom in mind,   enthusiasm at heart.

NFB-28 (Version 2015 )
(The best mid range DAC +amp we ever had)
Discrete  DAC+ Headphone amplifier / Preamplifier
With XLR / RCA analog inputs
DSD , DXD support from USB & I2S Input
32bit / 384K Sabre ES9018
32bit / 384K Asynchronous Transfer  USB-32 Chip

1, Upgrade to the Amanero combo384 USB module and H mode:
     Price +USD80 (Promo), the upgrade functions as below :
     A, Upgrade to the Amanero combo384 USB module for replace the USB32,  ( Choice this upgrade option, customer don't want upgrade the TCXO for the USB ).
     B, After upgrade, except the gain mode F and S, customer can select the gain mode H , the H mode is design for drive the HE-6 and other low sensitivity headphones and low output level sources . (In the H mode, the NFB-28 had 25DB gain ).
     C, A switch on rear for select the DAC / Pre output with / without volume control (The headphone output mode always had the volume control).
     D, Built in a jumper for customer select if want to dark the display at around 8 seconds after stop operate the unit .
     E, Built in mulriple jumpers for customer select the digital filter mode between Fast / Slow roll off ( Available of PCM signal input ) , and the DSD filer roll off between 50KHz / 60KHz / 70KHz,  and the digital filter select between NOS / Oversampling (Available of PCM signal input from USB or I2S ).

2, Upgrade to the Amanero combo384 USB module:
     Upgrade to the Amanero combo384 USB module for replace the USB32, price +USD45 ( Choice this upgrade option, customer don't want upgrade the TCXO for the USB ).

3, Upgrade TCXO for USB-32 and ES9018 for slight improve on the sound transparency .
     There two TCXOs can be upgrade  for the USB-32 and ES9018, cost is USD20/per,  without shipping delay ,If customer had choice the H mode upgrade option, the USB don't need upgrade the TCXO.

4, Custom order two pair RCA outputs:
       The NFB-28 default have one pair RCA and one pair ACSS output , If customers don't want ACSS output , free for replace by RCA output without shipping delay   .

5, Custom order HDMI replace RJ45 I2S input.
     Price is USD20, without shipping delay.

6, Custom order HDMI replace USB input.
     Free with 1 days  shipping delay.

7, Custom order the display dark at around 7 seconds after operated.
     +USD1,without shipping delay , If the customer choice the H mode upgrade mode, don't need custom order this function.

 Customer can custom order the different define of the I2S pins free.
Please note: Don't hot push / pull of the I2S cable. Any time must power off the units then push or pull the I2S cable.