Does anyone have any experience with http://www.alpine-usa.com/US-en/products/p...-620M&tab=D ?

I'd love to hook this up to my deck or get one of the new decks with USB native and connect a 160GD 2.5" external drive. It says is supports Mass Storage so I'd suppose it would support HDD's in addition to thumb drives.

I would suspect that it depends on how much power the deck can provide across the usb connect.

If the drive is external powered, it might not matter and theoretically should work.

I know the Pioneer version puts out 500ma, I'd suspect the Alpine is the same.

I know also, that some have limits on both folder count and file per folder limits, so it may be possible to have more tracks on a drive than the player is able to read.

I have a kenwood head unit (don't remember the specific model offhand) with a USB connecter on the front faceplate and I use a 2 gig usb flash/key drive and it works great. My only issues with it is no support for lossless/flac support, replay gain, or gapless playback.

As long as it meets USB2.0 standards then everything should be fine when powering the external hard drive (unless the external hard drive requires an AC power source). I would think that this uses USB2.0 and not USB1.0. Just to be safe though, I would e-mail Alpine and ask them. If it is USB1.0 then you have to purchase a external hard drive that is compatible with that (for powering reasons).

My Kenwood CD deck has a USB2.0 port built right on the cover of the unit, I can't imagine a company such as Alpine using USB1.0 (or USB1.1).

I've got a Sony CDX-GT414U unit, quite new one, with USB.
It's great with a flash memory stick.
However, even with 1 Gb stick it takes some 20-30 seconds for the unit before it starts playing. I suppose it's reading the whole file/folder structure and looking for mp3 files.

I also tried it with my 20 Gb HDD-based mp3 player, and it takes forever for it to start playing. And then also there is a limit of some thousands of songs. But this initial "read-in" time is really what makes it totally impractical.

So, with this Sony unit, USB is good only for a memory stick.
And the HDD-player I connect thru an audio-in.

By the way, a REALLY great feature of this particular Sony model is that it has preamp for the external audio sources (such as my mp3 player), adjustable up to +18 dB! Without such preamp the sound is way too quiet.