The amPlug 2 works great with my electric guitar, but batteries last only about 14 hours, which is just over a week of normal practice.

I would try rechargeable batteries but I was wondering: has anybody tried to feed it with some other source or have any hacks to recommend?

While the SO Electrical Engineering community might have better knowledge, I thought I'd more likely find someone with the same problem here.

  • 1
    "Only 14 hours" is a very long time for musical equipment. Most things that take batteries (e.g., active basses, wireless transmitters) get a fresh set for every gig. Based on the battery lifetimes, it looks like the intention of Vox is that you would have rechargeable batteries that you take out and recharge after every practice. Jun 5, 2016 at 14:47
  • I use AA Lithium batteries in my Taylor Acoustic and they seem to last at least twice as long as Alkaline batteries. Never mind that they are 4 times as expensive. Duracell Quantum Alkaline Batteries claim to have a longer life than others - but certainly not as long as lithium. Jun 5, 2016 at 19:16

3 Answers 3


This device is really meant for practicing when on the move. If you are playing somewhere where you have power there are other headphone amps that are way better.

If you absolutely must use it and want a power solution, simply buy a power supply that provides 3V and wire it directly to the terminals in the battery compartment, making sure you have them the correct way round.

As Todd commented, 14 hours is a long time for an audio device, so for what it is, it does pretty well - I'd stick with the Amplug for practicing when sitting in a park, or when travelling. For practicing in the house I'd buy a proper headphone amp if I needed to be quiet.


The amplug works just fine with rechargable batteries. I have a set of 4 NiMh batteries with 1000 mAh each and had not problems so far. While I play with one pair the other rests in my charger, so I never run out of stock. And a single pair lasts for many hours.

There's no need to overcomplicate things with a seperate power supply or to dilify this device. I find it perfectly fine for everyday practice and not just for travelling and the like.


The accepted answer specifies 3v for a plug-able power supply "hack" since AAA alkaline batteries have a nominal voltage of 1.5v and they are connected in series: for 2 identical batteries in series, the voltage is additive, the capacity is as if there is only one battery.

For 2 identical batteries in parallel, the voltage is as one battery, but the capacity is additive.

So a pack of 2xAAA wired in series which is then wired in parallel to another 2xAAA wired in series would give 3v with twice the capacity.

Of course it would be simpler to just swap batteries after 14 hours.

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