3vdc -12 volt Universal AC/DC Power Adapter USB Port | 8 Reversible Polarity Positive or Negative Tips Center Tip 3v 4.5v 5v 6v 7.5v 9v 12v 1a 12w Transformer 5.5mm 2.5mm 2.1mm 3.5mm 4.0mm 5.0mm 1.7mm

Works good. Solution for hard-to-find jack polarity, negative inner conductor. No measured power draw at no-load, measured with 0.1 VA and 0.1 watt resolution. Yay.

Bought this to power my Sony MZ-N505 minidisc player, 3 Volts, center positive. Works like a charm! Great value since OEM power adapters are like $80. There's a tip that fits perfectly and the voltage changer is just a potentiometer on the back, simple design. Will be buying more for other devices.

works perfectly fine thank you.

Fantastic product! Best universal power supply for the money! Firstly, the reversible polarity tips (a feature that sets it apart from most universal power supply products) were a must for my skating rink toy display that plays Christmas music. FYI, many sound devices require a negative polarity center/tip (see the little +/- diagram usually shown next to the port on your device), yet most universal power supply products are only configured for positive polarity centers. Secondly, the size and polarity is marked clearly on each respective tip, so there is no guess work. Thirdly, unlike other products that include six (6) conventional tips, this product provides eight (8) tips, which is especially helpful if you have electronics with less common port sizes. Fourthly, the little tip holder is handy, so you won't easily lose one or more of the tips. Fifthly, the 30 watt/2.5 amp max current ensures that it will power a broad range of devices. Finally, the USB port is a bonus! Even though it may not be necessary for many users, it can provide great utility for those with a limited number of electrical outlets and many devices and for those traveling abroad considering that it can be used in countries with 220 vac outlets. Of course, I am very happy with this purchase!

GOOD: Very versatile - number of different tips & configurations should be able to fit just about any application. BAD: No voltage label on adapter like it shows on box, but not tough to figure where it's set - turn arrow to one end & count detents as you turn to other end. Images in instructions not very clear even with magnifying glass - image on box much easier to see how to set polarity at device.

Works as stated seems to be good quality

Works amazing and you can actually switch the polarity, so I can use it for a lot of devices around the house.

I ordered this device to power my Radio Shack AM/FM/SW Radio Model DX-375. It did not work for me because I heard a loud hum, presumably produced by an unfiltered ripple riding the DC voltage. This device may work fine for running a non-audio application. I returned the device for a refund which Amazon processed promptly. Thank you, Amazon. If you know of a 3-volt, 10 wats, ripple-free DC output adapter, I would like to learn about it.