I have taken my NFB-1 back home for 2 weeks now. The NFB-1's 5V XLR proved to be too hot for my Yamaha A-S2000 amp (max 2.8V input signal) and caused clipping. Coaxle out from my Yamaha DVD-S1800 DVD/SACD player was totally unlistenable, and I had to set -7.5db for the Foobar Replay Gain so I can play from my notebook. To solve the problem, I ordered a TC Electronic Level Pilot for connection between the NFB-1 and the Yamaha A-S2000 amp. I emailed Kingwa the circuit diagram of the Yamaha A-S2000 and asked if there is any adverse effect on frequency response. He checked and said there would probabaly be a -3db at 500kHz. So I went ahead to buy the TC Pilot.
For those who are interested in how a volume pod or passive preamp can affect the frequency response (i.e. how much it would act like a low pass filter and cut treble), there is a detailed explaination at http://www.dact.com/html/technical_info.html. There is even a Excel worksheet for calculation.
1. Dell D520 notebook (with docking station) -> Foobar2000 1.1 (replay gain off, fading off, playback buffer 50MB, 200ms Playback buffer, 24bit output format) -> Windows 7 WASAPI using built-in TE-7022 driver -> Monster 1.5m USB cable -> Audio-gd DI (USB bus powered) -> Audio-gd BNC cable -> Audio-gd NFB-1 -> Audio-gd XLR cables -> TC Electronic Level Pilot -> Yamaha A-S2000 amp (via XLR inputs) -> NHT 1.5 speakers
2. Yamaha DVD-S1800 DVD/SACD player -> cheap 75ohm coaxle cable -> Audio-gd DI (USB bus powered) -> Audio-gd BNC cable -> Audio-gd NFB-1 -> Audio-gd XLR cables -> TC Electronic Level Pilot -> Yamaha A-S2000 amp (via XLR inputs) -> NHT 1.5 speakers
I set the TC Level Pilot to output about the same sound level from the DVD-S1800 -> Yamaha A-S2000 amp via the RCA inputs. It is at about 2 o'clock position.
My previous setups for comparison: E-mu 0404USB for Computer Audio, Yamaha DVD-S1800 -> Yamaha A-S2000 (RCA inputs)
The NFB-1 is my first stand alone DAC purchase. It proved to be a much better DAC compare with the 0404USB. I have to say all my expectation are fullfilled: Much more revealing, Much more dynamic, Much better instrument seperations, and "musical". The difference between the 0404USB is quite dramatic, while the difference between the DVD-S1800 is more subtle.
Although I have never listened to any PCM1704 DAC, I did have an old Philip CD950 player which used the Bit-Stream DAC 7 chips. I find the NFB-1 implementation of the Sabre32 very musical to me. There is no harshness I can find. Although I find post 2000 recordings sound more dynamic and attractive than those old 90s recording throught the NFB-1. Sound stage increased in depth but wideness is limited by my NHT 1.5 speakers seperating only 1.5m apart
Some of the materials I tried:
Kelly Clarkson - Thankful (16bit 44kHz)
Diana Krall - The Look of Love (24bit 96kHz DVD audio)
Faith Hill - Firefires (16bit 44kHz)
Enya - The Celts (16bit 44kHz)
Absolutely Disney - 40 Magical Masterpieces (16bit 44kHz)
Tony Leung (Mandarin) - Absolute Collection (16bit 44kHz)
Cheung Ying (Pipa) - Dancing in the Wind (16bit 44kHz)
Jim Brickman (Piano) - Grace (16bit 44kHz)
Jim Brickman (Piano) - Destiny (16bit 44kHz)
Eurosport TV recording - MotoGP 2010 Austrialia GP Philip Island
Many other Mandarin vocals from 80s to 90s
I am happy with the NFB-1. I think it will serve as a center piece for future upgrading. I think my pair of NHT 1.5 speakers is the limiting factor of my home system now. I will DIY another pair of bookshelf speakers using Seas drivers once I move to a larger apartment.
The Audio DI, while good, seems to be not as stable as my old Emu0404 USB on USB connection. The Audio-gd DI USB connection is much more easily affected by other Windows 7 processes.
Edited by borrego - 10/31/10 at 7:30pm