Kinter MA-180 USB questions?

[GlynH]

Hi there,

My new arcade coffee table is fitted with a Kinter MA-180 amplifier and I have a few questions.

1. The USB output on the back is labelled as charge output but it won't charge my iPhone I'm guessing because the rated output is too low. It is of course 5v but I did read somewhere after a lot of searching it is only 100mA so nowhere the 1A an iPhone needs to charge although it might actually charge a simple MP3 player.
Would this assumption be correct or do I have a bad/faulty USB output on it?

2. Every time I switch on or off at the mains there is a thump through the speaker which is probably the capacitor charging/discharging? I am guessing there is no way to stop that apart from keeping the table switched on and just putting the PC inside to sleep as the amplifier is on as soon as mains power is applied.

Does anyone know if there might be a better replacement amplifier that will not make the thumping noise and that also has a decent USB output to charge an iPhone or even an iPad please?

Size is quite important as there is not a lot of space in there...

I have seen a similar Lepai amplifier advertised with USB but they don't mention the rated output so I might be in the same boat.

Would be good if the USB also allowed audio input from the iPhone as well but it's not the end of the world if it doesn't!

Thanks & kind regards,
-=Glyn=-

[SavannahLion]

I'm not quite sure I understand the USB requirement here. You can buy a dedicated USB charger and mount and wire it in. I have a 4 port hub I abuse regularly charging all manner of devices. It's tiny, about half the size of a deck of cards. Newer models are likely even smaller.

Disassociating a requirement would open up more choices for you....

[PL1]

I did read somewhere after a lot of searching it is only 100mA

IIRC, per the USB spec, there are three options: motherboard header, a non-powered hub (4 port) and a powered hub.

- A motherboard USB header should be rated for 500mA.

- A non-powered hub port should be rated for 100mA (manufacturers regularly exceed this part of the spec) -- 100mA for the hub circuit + (100mA * 4 ports) = 500mA

- A powered hub can easily provide the >1A that you need to charge your phone.


Scott

[GlynH]

Thanks for the replies guys!

A couple of things;

I am trying to kill two (or three) birds with one stone here;

1. Looking for a way to charge my iOS devices (iPhone & iPad) without having to turn on the PC to power up the existing USB port which with its 500mA output is a slow procedure in any case.

2. Doing away with the switch on thump from the amplifier.

When the arcade table is plugged in and turned on both the power supply & anything connected to it (amplifier in this instance) is powered on. The PC could be in sleep mode at this point.

Easy option; If I could source another mini-amplifier that had a 'soft-start' to prevent the switch-on thump and if the USB port on this new amplifier was capable of outputting enough current to charge - problem solved.
If this USB port were also capable of behaving as a digital audio input then all the better which would be all of the three things I mentioned above sorted in one fell swoop.

A big ask I know but a perfect solution.

If I could only achieve two of three things (minus the USB audio input) then not the end of the world and still a worthwhile solution as I could live without the audio input part of it which would be decidedly low-fi in any case.

I could of course wire in a dedicated USB charger but this is another, separate device and not as elegant a solution as having the amplifier achieve this. The fact that I am limited both for space & access does not help matters.

Another option would be to utilise the unused 5v output on the cabinet PSU but this is rated at 6A (and could increase to 8-9A) so not ideal to use as a charging circuit as the potential for causing damage if there was a short or other failure in the iOS device could be catastrophic for both device & table.

Again this could be overcome by fitting a fuse or breaker in the wiring from the PSU but as above not such an elegant, all-in-one solution as finding a new amplifier that could supply the 1-2A required for this purpose.

The search continues...

Thanks & kind regards,
-=Glyn=-