Airport Express clicking sound


I'm hearing a clicking or popping noise when using my Airport Express. It only happens on very "pure" sounds, like a high trumpet or a high soprano. Perhaps it is occurring other times but I can't hear it then.

I'm going from iTunes on a laptop to the Airport Express, digital out to a DacMagic. I know it's not the DAC, as I burned the same files to CD and played it through a CD player hooked up optically to the DacMagic, and no problems. I also tested the same files going directly from an iPod Touch to the Airport Express.

The only other thing it could be is the router, but I don't have a second router to test with. Any ideas of what's going on?
markhyams
Thanks Steve!

PSA suggested I approach the skipping as a PC problem, so I: upgraded the system in my MACbook, updated to latest Itunes, put in new memory (8GB), and replaced the external drive on which I store my music. I also did an activity search, to make sure other programs were not running and interfering.

This did not help, nor did swapping out USB cables, so I remained suspicious of the DAC, especially since the problem started when I installed the PWD MKII upgrade.

I therefore obtained another DAC (PSA DL III) and switched it into the system -- that appears to have resolved the problem.

I suspect it is something to do with the USB in to the DAC, since the problem did not occur when I connected a CDP transport via coax.

Curious if you have any further thoughts; I'll be in touch with PSA presently.

John
Update: I replaced the Airport Express with a Squeezebox Touch and the problem disappeared. Clearly something was going on in the playback chain with iTunes and the Airport Express. What that something is, I don't know. Interesting to say the least, as the AE is purported to be "bit-perfect." Now with Logitech Media Server and the Touch, all is well.
Your computer or the AE could have been locking into a legacy and/or overloaded WIFI network.

I had a similar problem recently, but the cause was far more obvious... the noise started right after I replaced my generic "had it laying around" optical cable with a fancy new optical cable that turned out to be defective or was damaged during shipping.
Your computer or the AE could have been locking into a legacy and/or overloaded WIFI network.

But I have the same wifi network and the same computer running Logitech Media Server.

I really think something was going on with the AE, although I never tested it with its analog outputs.