[drews]

So I just received my Zhaolu D2C (CS4398 with upgraded headphone amp) from iFi and I'm having
a bizarre problem. I'm experiencing consistent, harsh popping noises but ONLY through the RCA outputs,
and ONLY from certain kinds of audio, for example:

Some iTunes music store song previews, but not others
Some video podcasts (i.e. Diggnation but not others)
Some native applications (iDVD theme music)

I'm using an Intel Mac Mini with the optical digital output (mini->Toslink).

Furthermore,

All audio through the headphone jack is always fine.
I have the same problem if I use my old Turtle Beach AA USB->Toslink with a different cable.

Does anyone know which DAC components are bypassed for the headphone amp but not the RCA-outs that may be causing this?

Here's a link to Morcheeba's "The Sea" which causes the problem:

iTunes link

If anyone can offer any possible explanations or can duplicate the problem, I'd really appreciate it!

Drew Stevens

 

[Sinwerm]

Running a D2C also , listened to the link and sounds clear and very nice actually. Im not familiar with Mac settings so I won't be much help but have your tried different stream rates (if thats the right phrase). Possible to try the coax connection maybe the toslink on the Zhaoulu is not supposed to be all that great with toslink from what I have garnered in other threads. Very odd problem really , it only does it for certain music files through the RCAs and others are fine huh ? Good luck can you try it on another computer ? to eliminate the D2.0c as the source of the problem. Good luck.

 

[drews]

I'm happy to report that the Zhaolu was NOT the cause of the problem!

The distortion was actually being caused by my Klipsh iFi speakers. I didn't realize this at first because they didn't exhibit any problem when I used the computer's analog output UNTIL I raised the computer's volume past a certain threshold.

I'm now pretty sure that my problems are due to amplifier clipping. Most of my music had been mp3gain'd and therefore had no problem, but iTunes songs (like the sample I linked to) cannot be mp3gain'd due to the DRM protection (remind me to never purchase a song from iTunes again!).

Fortunately the Zhaolu has the variable RCA outputs which will prevent the clipping in the iFi.

Thanks for responding Sinwerm!
Drew

 

[Sean H]

You likely already know this but if not, go into your iTunes preferences and then "Playback" and make sure the boxes are NOT checked for "Sound Enhancer" and "Sound Check".

 

[drews]

Yeah, neither of those were on (or more importantly perhaps, the EQ)... I guess the Klipsch iFi (or at least mine) was just not designed to cope with a line-input signal.

Drew