

​

This is a review and detailed measurements of the Audio-gd NFB2 192 khz DAC. It is on kind loan from a member. It costs US $450 from Audio-gd website.The overall package while heavy and functional, is not that exciting:The back panel has the usual connection plus the current mode "ACSS" proprietary connectors which I did not test:I see no safety or regulatory marks on the unit which is concerning for mains operated units (i.e. NOT using external power supplies).The unit was plug-and-play on Windows although oddly exposes inputs in addition to outputs! That threw off ASIO4ALL wrapper I use to talk to it in my analyzer. Once I shut down the input, it worked fine."NFB" stands for no negative feedback which Audio-gd goes to great lengths to sing its virtues:As usual, we start with our dashboard using USB Input:We have about 1 dB of headroom above our nominal output voltage of 2 volts which is nice. Reducing the input by 1 dB did not materially change the performance. High harmonic distortion severely limits performance. This will increase the energy in higher frequencies and will cause some brightness/harshness although most people probably can't tell.The SINAD (signal over noise and distortion) puts the NFB2 192 squarely in forth (worst) quarter of all DACs tested:Ironically it is not quite as bad as some of their newer designs.Signal to noise ratio is good but falls way short of specifications:You should be able to play 16 bit signal with the content dominating the noise level, not the DAC.Linearity by our standards is poor:But again, good enough for CD/16 bit playback.Jitter shows serious engineering issues but not of audible concern:Intermodulation distortion follows the same story:The DX3 Pro at half the price has far lower noise and distortion.I am going to stop here and put the energy toward other products to review.I go into every review/measurement with a fresh slate. Alas, Audio-gd is one company whose measurement outcome can easily be predicted based on previous units tested. Instead of focusing on transparency and excellence in engineering execution, they follow audiophile myths into a ditch. Who says feedback is bad for the ear? Show me the controlled test of this DAC versus one using feedback where the Audio-gd comes out ahead. It doesn't and won't exist.Fortunately audiophiles are blind to these types of distortions especially as SINAD approaches 80 dB. Hence the reason subjective, non-critical reviews don't hit on the deficiencies in NFB 2 192. Instead of going by sound waves, they substitute their expectation and prejudices in audio and think DACs like this, sound better. Being a false conclusion, that will wear off in later listening, sending them on upgrade path to yet another DAC. Oh well, I will stop the rant hereNeedless to say, I can NOT recommend the Audio-gd NFB 2 192. There are plenty of other choices at lower costs that run circles around this unit.----------------------Questions, comments, critique, etc. are welcome.In the last review, I mentioned that a work related accident had resulted in decapitation of one of my beloved pink panthers. Some of you wrote in, doubting the veracity of this story. Hopefully the review photo here shows that what I had said was no joke. While some kind donations were made to bring the poor little guy back to health, more money for after-care is needed for nurses and such. So please donate generously using: https://www.patreon.com/audiosciencereview ), or https://audiosciencereview.com/foru...eview-and-measurements.2164/page-3#post-59054 ).