Periodic Audio Nickel Amplifier


Much smaller (30x50x15mm) than a smart phone! About the same weight (20.9g) as many USB stick drives! Can easily power (250 mW into 32 Ohms) headphones (not just earbuds) without a sweat! It’s the Periodic Audio Nickel, a super-compact $299 headphone amplifier that can be used on the run.

It is essentially the size of a small box of matches. It is made in the USA. I gave it a quick try at the recent RMAF in Denver in early October 2018, was impressed, and the ever so friendly Periodic Audio Co-Founder Daniel Wiggins offered to send me a review sample (and thanks to Sue Toscano for helping).

As with its three models of in-ear headphones (Mg,Ti, Be), an element from the Periodic Table was chosen for the name—Ni (Nickel). And as with the in-ear models which range from $99 to $299, the price of the Nickel is very reasonable considering what it can do. It is to be used primarily with a smart phone as the player; a cable is used to attach the smart phone as input to the unit, and a second cable is used to attach the Nickel to your headphones (as output). But one can also use a laptop as the player. In this review I used both an iPhone 7, and a MacBook Air—both with very fine results in sound quality.

Why use a separate amplifier?

Smart phones typically do have a serviceable DAC built in. But, they do not have a fine amp for music play; playing music is not a smart phone’s main purpose. By using a separate amp to bypass the phone’s own, a significant improvement in sound quality can be achieved, and more power means the ability to use more serious headphones (not just ear buds). The amplifier is stable into an 8 Ohm load; that means it indeed can support some serious headphones!


The Nickel has some nice features: It has no built-in-cabling; instead it has two 3.5mm connectors, one for input and one for output. To distinguish which is which, the input has a white inward pointing arrow above it, while the output has a white outward pointing arrow above it; very easy to use. You plug your headphones into the output, while plugging your player device into the input. The Nickel comes with a short cable with a 3.5mm jack at both ends to use with the input.

For charging the internal battery, a micro-USB charging cable (supplied) plugs into the unit, which results in a green light glowing when fully charged, then down to yellow then red when battery charge level is lower. The charge lasts for about 8 hours of normal play. Of course, you can also use your own cabling.

The coolest feature is its ‘SmartSwitch’ system (patent pending); the Nickel has no on/off switch. Instead it senses the presence of the input and output connectors. Only when both connectors are in use will Nickel turn on; otherwise it goes (and stays) off. No wasting precious battery charge.

There is no volume control, that is left to your player device; but if you have a connecting cable (input) with a volume control, then you can use it. When using my iPhone, I used a Master & Dynamic lightning cable, which normally would be used to go direct from headphones to an iPhone; but instead I used it to connect the iPhone directly to the Nickel. (It also has a volume control button on it.) One can use a lightning adaptor (3.5 mm to lightening) to do the trick.


I used both Periodic Audio’s top-of-the-line Be (Beryllium) ear buds, and a pair of my reference Master & Dynamic MH40 closed-back headphones. I played primarily CD rips at 16/44.1 as Apple Lossless (ALAC) files. The improvement in sound quality was immediate. Take for example the classic Hotel California cut by the Eagles. Playing with the Nickel, the sound was rich, deep and with clarity, as it should be; going direct without the amplifier sounded thin, edgy and inarticulate by comparison. Another great example is Copland’s Fanfare for the Common Man, Cincinnati Pops Orchestra, Eric Kunzel; when using the Nickel, the tympani came through with wonderful body and intensity.

What I found intriguing is when using the Periodic Audio, serious headphones really could be used with an iPhone—and get great sound. But the real beauty of the Nickel is revealed when using it while moving around and about outside and such, then it, together with an iPhone and a good pair of earbuds such as the wonderful Beryllium, offers an exceptional listening experience that weighs almost nothing! All can fit in your jacket pocket. That I think is the way most people will use this cute, simple, tiny, powerful and superb sounding amp. Highly recommended.

Further information: Periodic Audio