USB Soundcards - faint popping/clicks

I am currently using a G4 iBook 933 MHz and have my new Waveterminal U24 connected to a DAC and Headphone Amplifier. The sound is really fantastic. I do notice every minute or so, I get a very faint pop or click sound. Sometimes I go longer without hearing it, but it occurs often enough that I notice it. I have tried to research this and there seems to be an opinion that this is just a USB audio problem and nothing can be done. I have experimented with settings. I have more than enough RAM than I know what to do with. I am using iTunes and so there really aren't any settings to adjust there except turning off all of the enhancements.

Anyway, anybody have any suggestions for USB audio pops?
This is a buffering/cacheing problem. You should try different buffer size settings and latency settings if you have those available. If you are using iTunes player these usually go away. They can occur with Foobar2000.
Thanks for the info. I am actually using iTunes and I don't have the ability to adjust the buffer, at least I haven't seen it anywhere. My hard drive is almost maxed out and somebody suggested maybe I need to clear more space for the computer to use its virtual memory. I am still pretty far under my maximum RAM memory, but if the computer uses the hard drive for buffering/caching, could this be the issue?

When I used my Transit I didn't notice any of these faint clicks, however, the sound was not as detailed. I also had the ability to control latency with that driver. The ESI Waveterminal card I am using now, does not have any controls for latency on the Mac.

You want to have at least 20% free on your hard drive. Otherwise you will have the potential for major file fragmentation that will result in low performance and the problem you describe above.

Specifically, I'm pretty sure the problem is the fragmentation. When you have only 1 or 2% (or 10%) space free on a drive, the maximum *contiguous* space on the drive could only be, say, 400K in size. Then if you download or rip a 30MB file, it will need to store parts of it in around 8-10 different places. Then, to read it back, the drive needs to jump from place to place, and when this happens you can have buffering problems. This problem also compounds itself when *other* files on your hard drive are fragmented. It results in lousy IO performance.



Wow thanks for the information. I have my audio collection on a firewire drive anyway, I will just clear a bunch of files from the hard drive.

Is there a way to clean up fragmantation on a hard drive? Is there a good utiltiy for this? Or, if I get rid of the extra files will I be fine then?
Go to START> Programs> Accessories> System Tools> Defrag. If this sytem has never been done it may take a while. I would run disk clean up first then a scan disk second then the defrag.. Make sure when you run the defrag not have any programs open, also if you use a screen saver you should go into your screen saver settings and switch it to none so it wont start up in the middle of the defrag . If your running XP or 2000 you will have to select the scandisk in tools and then reboot the pc so it can run before it goes into windows.
I have a similar setup with Powerbook G4 feeding a Waveterminal U24 feeding my dac. I've had no clicks or problems. Likely a settings issue.


What settings do you use in the control panel?

Also how much RAM do you have?

I have determined this is not an iTunes issue. No pops coming from the headphone jack, nor when I use my Transit (it has a driver). Could the Waveterminal be drawing more power or making more demands from the system than the Transit?

I might try and do the following. Any Mac users think this would be of benefit?

Clicking is frequently a sign of some sort of clock issue. Make sure you have the most up to date drivers for the Waveterminal.
Thanks onhwy61. Unfortunately, there aren't any drivers for Mac OS X, they say just plug and play.

The only other thing I could recommend is making sure you have all the upgrades for whatever version of OS X you're using. This doesn't mean you have to upgrade to the latest version, but that for whatever version you are using that it has all the software upgrades.
Problem fixed. I recorded into the unit for the first time. This process must have reset a driver or something. The unit was restored to its original settings before I download the problem unneeded driver.

Pops are gone and I am happy.

I'm still building my first system, toying with using a Mac for playback. Anyone here A/B their Waveterminal>DAC against some other transport and the same DAC? I'd be very interested in what you've heard.

Also considering hooking up the Mac to an HDTV for watching movies. Yes, in 2-channel, that's fine with me. Wondering if Mac>Waveterminal>DAC>Amp might push the audio out of sync with the video. Any first-hand experience with this?
If you defrag the disk and kill all other applications except the player, you should not get pops and ticks. I was getting pops and then they went away after I defragged. After I installed Turbotax and left it running, the pops came back.

Steve N.
Empirical Audio