Thinkpad T20 Audio Line Out produces regular click pattern

[emotif]

Hello. Wondering if anyone with a T20 like me (or perhaps any Thinkpad for all I know) has noticed an extremely regular noise pattern which is present when listening to speakers via the line out.

The pattern a rapid 7 clicks happening every 3-5 seconds. It's present even when there's no hard drive activity whatsoever.

I can't seem to find any newer drivers for the Crystal Sound Fusion.

I thought it could be electromagnetic interference from something else in my flat (like a wireless card), but I've travelled to other locations and the problem persists.

Anyone else ever notice this and/or come up with a solution?

Thanks in advance.

Mark in San Francisco

[bhtooefr]

It DOES sound like EMI...

Where are the other locations you are going to?

We once had a USR WinModem, and the electric fence next door caused it to send clicks every second (electric fences sometimes pulse rather than go continuously) down the phone line...

[beeblebrox]

Yes, I know that problem quite well. I had it on my T20 and now on my T40p as well. It is the power brick, that emits RF waves because it is a switched high-frequency voltage converter. The power line is not really clean, even when using a shielded audio cable, because the noise is propagated throughout the motherboard. It becomes worse with a docking station.

I thought about buying an old fashioned coil transformer to avoid the high frequency pitch. But they are heavy, big and ugly.

A possible solution would be using an external USB audio decoder (Creative Audigy,etc.) or WLAn to the hifi system (Terratec Noxon).