I purchased this device from a wal-mart here in maine. It worked like a champ first time out of the box, a really neat little device.
I bought it so that I could play mp3 audio through my van's existing sound system.
I have used it with a sony walkman cd player and with a usb flash drive. It worked fine both ways. However I did notice a bit of "device noise" when using the cd player.
Also , The manual that came with the device is wrong on at least two points:
First, Contrary to the Specifications listed in the user instructions, the device will work with flash drives greater than 512mb. my pen drive is 1 gig and it works fine.
Second, The unit will also play back files encoded at greater than 128kb.although files
will begin to generate a bit of noise as the bit rate is pushed beyond 200 kb.However,
this could be a limitation of my van's sound system as opposed to a flaw in the modulator itself.
All in all, it is a terrific little gadget, well worth the $30 I paid for it.and considerably less expensive than replacing an entire stereo head unit .