USB Audio Adapter -> Hot Earbuds!

[dpwe]

I bought the USB audio adapter for use with my Pi: http://www.adafruit.com/products/1475

[I'm mostly interested in audio input, which works at least through alsamixer (monitoring input on output).]

But I've noticed that when I use my old iPhone earbuds plugged into the adapter, they get hot. Not burning hot, but definitely a distinct warm sensation in my ears that makes me want to unplug them before they are permanently damaged.

It makes me think that the adapter is dumping a DC bias through the earbuds. Sure enough, my multimeter reads a steady current of 46-49 mA going into the earbuds, and a DC bias of about 2.2 V across the output. That would give a steady dissipation of about 100 mW in each earphone.

Anyone else noticed this?

DAn.

[adafruit]

Thats unusual, we haven't seen this issue before. email support@adafruit with a link to this thread to get a new one in case its a one-off problem!

[whitebabylon]

I bought a USB audio thing off amazon and just got it. I noticed the same thing about my ear buds getting hot. Well that's my two cents.