Tianyun Zero DAC - New 2009 Edition - Page 23

Thanks for the answer. Just removed the adapter and the ZERO worked - although sound was a little bit muffled (otherwise the opamp wouldn't be necessary). But  no destortion and full amplification. Just ordered a new OPA627. Let's see...

I've had my eye on the zero for a while because of it's price, but recently read many great things about audio gd's nfb-12. This would be my first DAC/amp so I was wondering if there is any significant difference between the two that would be apparent to someone new to this like me. BTW I'd use it with my HD650's and asus laptop. 

Anyone has comment on this? Thanks

Quote:

Originally Posted by turbo1 

I've had my eye on the zero for a while because of it's price, but recently read many great things about audio gd's nfb-12. This would be my first DAC/amp so I was wondering if there is any significant difference between the two that would be apparent to someone new to this like me. BTW I'd use it with my HD650's and asus laptop. 

Anything op-amp based is going to sound the same given they share the same chip. 

I finally found av weakness in the Tianyun DAC Zero 09 (OPA627). 

If you're curious about the performance of your own system, the following samples contain a 30kHz and a 33kHz tone in a 24/96 WAV file, a longer version in a FLAC, some tri-tone warbles, and a normal song clip shifted up by 24kHz so that it's entirely in the ultrasonic range from 24kHz to 46kHz:

Intermod Tests:

30kHz tone + 33kHz tone (24 bit / 96kHz) [5 second WAV] [30 second FLAC]

26kHz - 48kHz warbling tones (24 bit / 96kHz) [10 second WAV]

26kHz - 96kHz warbling tones (24 bit / 192kHz) [10 second WAV]

Song clip shifted up by 24kHz (24 bit / 96kHz WAV) [10 second WAV]

(original version of above clip) (16 bit / 44.1kHz WAV)

Assuming your system is actually capable of full 96kHz playback, the above files should be completely silent with no audible noises, tones, whistles, clicks, or other sounds. If you hear anything, your system has a nonlinearity causing audible intermodulation of the ultrasonics. Be careful when increasing volume; running into digital or analog clipping, even soft clipping, will suddenly cause loud intermodulation tones.

Source: http://xiph.org/~xiphmont/demo/neil-young.html

I hear noises in all the above tracks, noises that should have been filtered out by the DAC... 

Because of this I have to restrict sample rate to 44.1 KHz in the software player (Audirvana+). If the DAC can't handle samplerates correctly, then the feature becomes pretty useless...