USB Speakers - Any Problem With This Idea?

[CharlesT]

I have a set of USB speakers that I'd like to use with my Sansa E200 on job sites.  

I thought I'd take a trashed USB hub and rewire it so only two ports work.  Each port gets 5VDC from a wall wart capable of 1.2A.  The data line from the E200 gets routed directly to the data line of the USB speaker et voila a cheap jukebox that doesn't use batteries and keeps my player charged.

Any possible setbacks to this idea?

[Llorean]

USB speakers require that the e200 support USB audio, which it doesn't. Rockbox just barely has a new UMS mode, but nobody's even working on a driver for such hardware.

[CharlesT]

Blast.  

OK how about taking the audio out from the headphone jack and routing it to the data line of the USB speaker.  

I'm grasping at straws now aren't I.

edit spelling

[Llorean]

You do know that there are speakers that draw power from a USB cable, but audio from a headphone jack. You could just use those. Get a cheap USB hub, just use it to provide power to the MP3 player and the speakers, and run a basic audio cable between them. I do this all the time (well, I use the USB port on my Gigabeat's dock to provide power to the speakers, actually, but it's the same concept). I know creative makes some Travelsound speakers like this, and there are surely many others.

Because they're powered from a USB port, you can get USB battery packs to power them on the go as well, and because they use a normal audio cable, you can use them with a much wider range of devices.

[markun]

USB speakers require that the e200 support USB audio, which it doesn't. Rockbox just barely has a new UMS mode, but nobody's even working on a driver for such hardware.

It also requires USB host support, which I don't think anyone has worked on either.

[CharlesT]

You do know that there are speakers that draw power from a USB cable, but audio from a headphone jack. You could just use those.

Good idea but I already have a set of USB speakers that I bought to make an old Dell laptop into a jukebox.  I just wanted to reuse what I had.  I'll have to open the speakers and see if I can attach a jack to the data lines and if the E200 will work when plugged into it.

The concept I had was to provide a small AC powered jukebox to take on to job sites.  I'm a cabinet maker and the laptop idea didn't pan out because too many other contractors on site would play with it.

I could, I suppose, use the Sansa firmware when on site.

[Llorean]

The Sansa firmware shouldn't work with them either...

[CharlesT]

OK What am I missing?

Is there no USB playback regardless of the firmware I use?  (Then why does Sansa use a 30 pin connector other than to make it proprietary?)

I have to use the earphone jack for audio out?

If so then this will require a further rethink.  

By the way, thanks not only for Rockbox but for all the follow up posts you all have made.

I'll post the results of this project if anyone is interested.

[Llorean]

The dock connector is far more than USB. Among those pins is a line out for audio yes. But that's not USB and will not travel over a USB cable.

[CharlesT]

After a bit of a rethink, it looks like I'm going to have to buy a Griffin Power Dock.  

Using the circuitry inside the Power Dock, a 5VDC wall wart and a bit of rewiring of my USB speakers I should be able to create what I want.

Maybe.

Thanks to all who replied to this thread.

[saratoga]

After a bit of a rethink, it looks like I'm going to have to buy a Griffin Power Dock.  

Using the circuitry inside the Power Dock, a 5VDC wall wart and a bit of rewiring of my USB speakers I should be able to create what I want.

If what you want involves sending audio over USB, then no, thats not going to work.

[CharlesT]

I plan to take the audio out from the Power Dock and send it to the data line of the USB speaker.  I know that there may be sensitivity issues.

Thanks to all again.

CT

[markun]

I plan to take the audio out from the Power Dock and send it to the data line of the USB speaker.  I know that there may be sensitivity issues.

I still don't see how this can work since I assume the USB speakers expect digital audio through the USB audio protocol and the Power Dock audio out is analog.

Good luck anyway

[saratoga]

I plan to take the audio out from the Power Dock and send it to the data line of the USB speaker.  I know that there may be sensitivity issues.

Theres no possible way to do that short of putting a PC in between the Dock and the speakers, or writing a USB audio mode for rockbox.

[Llorean]

Well surely there's a DAC stage somewhere in the USB speakers themselves, mightn't it be possible to bypass that and do a little homebrew hardware work? A little more complicated, I suppose...