USB powered speakers OK to use?

The reason I asked is theres a limit on how much current can go through boards. Gizmo 2 has 4 usb ports, so technically 4*500 mA can pass through them, which is how much the stock power supply is. But probably the board can handle more than the stock PSU can provide.

If practice shows no problems its good enough for me.

Agreed - if my "puny" Pi can do it, Gizmo should have no issues. 

But wait, do you also use the Pi for charging and playing it at the same time? The one I'm talking about is powered by USB, doesn't have battery.

The portable AYL speaker has an internal Lithium ion battery.  Occasionally, I charge it up via USB with one of my computers.  Typically, I use it as a speaker with a portable small MP3 player or my wife's laptop, operating off the internal battery and using a simple 8mm audio cable.

The cable that was shipped with the speaker is a split audio/USB Y-cable.  Stick diagram:

  AYL  MiniUSB =========================== ----------- 8mm jack speaker output from computer

                                                                                        `----------- USB computer port for charging

So, yes, I am charging and playing music at the same time with the supplied cable.  Right now as I type.  (-:

Amazon URL: http://www.amazon.com/gp/product/B007OYAVLI?psc=1&redirect=true&ref_=oh_aui_search_detailpage

$15.50 Amazon Prime price - real bargain considering what it does.  Cute too as you can compress it into a ball.

The question is do you charge and play at the same time on the Gizmo, not your PC? Thats the whole point of the question.

Mark, I never answered this question specifically.  Apologies.

But wait, do you also use the Pi for charging and playing it at the same time?

I did for awhile.  That Pi has been redeployed as my son-in-law's Openelec/Kodi system.  Now, I use a different system now for charging and playing simultaneously.

The one I'm talking about is powered by USB, doesn't have battery.

Please identify "the one".  Do you already own this speaker or were you considering buying it?  If not yet purchased, the new portables (E.g. the AYL I own) can hold a charge like a phone and they are very portable - if that would interest you.

Mark, I never answered this question specifically.  Apologies.

But wait, do you also use the Pi for charging and playing it at the same time?

I did for awhile.  That Pi has been redeployed as my son-in-law's Openelec/Kodi system.  Now, I use a different system now for charging and playing simultaneously.

The one I'm talking about is powered by USB, doesn't have battery.

Please identify "the one".  Do you already own this speaker or were you considering buying it?  If not yet purchased, the new portables (E.g. the AYL I own) can hold a charge like a phone and they are very portable - if that would interest you.