This tiny DAC and headphone amp is a great way to use wired headphones on your iPhone

The disappearance of the jack on smartphones has proven to be a real annoyance for those of us who enjoy using our favorite wired earbuds or headphones to listen to music. However, humans are inventive and this has revived the market with the introduction of some USB DACs that can be plugged into a smartphone and powered by a pair of headphones.

You can pay anything from $10 for Apple’s own DAC to something high-end like the new Chord Mojo 2, which can bring audiophile quality music to almost any smartphone. If you’re looking for a DAC that works with iOS or Android, the Periodic Audio Rhodium combo DAC and amplifier dongle is both affordable and a smart little performer.

The Periodic Audio Rhodium DAC is tiny, with a USB-C connector on one end and a 3.5mm stereo jack on the other. The device can either be connected directly to a smartphone with a USB-C connector or, if you have an iPhone, the Rhodium can be used with a special Apple adapter.

The solution doesn’t look like a very elegant solution, but that’s the price we have to pay to use a DAC/amplifier on an iPhone. Apple has its MFI (Made for iPhone) program, which means manufacturers like Periodic Apple either have to pay a license fee for the Rhodium to work directly with an iPhone, or the user can simply spend the money for one of Apple’s Lightning-to-USB -camera adapters while we wonder why we’re so damn loyal to those people over there in Cupertino.

The Periodic Rhodium is a very simple device and does not require a driver. Simply connect it to your smartphone, then plug your favorite wired headphones into the Rhodium’s jack and sit back to enjoy the music.

I first tested the Rhodium on my iMac. The device is recognized by macOS, though unhelpfully it shows up as “Headphones” in the audio output, alongside the existing headphones already listed as the iMac’s own analog output. The chip used in the Rhodium is a Realtek ALC5686. It’s a small system-on-a-chip designed to hide the digital signal fed in by the phone or computer, which is then passed through an analog amplifier that drives the headphones.

The Rhodium is a basic DAC and can handle basic digital PCM files. There is no support whatsoever for MQA, DXD or DSD files. So if you have music stored as something other than vanilla PCM such as WAV or MP3 then the Rhodium is not for you. This won’t matter to most people as these other formats aren’t particularly widely used, with the exception of MQA on TIDAL’s Masters.

As you’d expect from a budget headphone DAC, the Periodic Rhodium isn’t overly powerful and doesn’t cope well with earbuds or headphones that are hard to drive. However, for most earbuds or headphones on the market, the Rhodium has enough punch to produce a decent volume.

The Rhodium has very low distortion and a respectable signal-to-noise ratio. 113db signal-to-noise ratio specification as well. The power consumption is quite modest with 23mA at 1mW output. That means the rhodium won’t eat up your smartphone’s battery, and I’ve certainly noticed that when using it with my iPhone SE 2.

Most people will use the Periodic Rhodium with their smartphone. Android devices shouldn’t have any problems. It works perfectly on Android phones with OTG. However, the device is a bit pickier when it comes to iPhones or iOS devices like an iPad. You need a newer iPhone running at least iOS 14.3 to work reliably. You’ll also need one of Apple’s overpriced Lightning to USB adapters. It’s a pain in the neck, but Apple doesn’t seem to like making our lives easy.

Sonically, the Periodic Rhodium performed far better than I expected. It produces a nice and warm sound with an analog feel. I paired it with Westone’s new Mach 10 IEMs and was blown away by the level of detail in the music. The soundstage was well focused, while the midrange driver tilted forward nicely. Overall, the sound is not bass-heavy, but not light either. Treble frequencies are smooth and detailed enough to create a spacious soundstage.

It’s fair to say that the Periodic Rhodium has a wide tolerance of all musical genres and a relaxed and pleasantly civilized presentation. It certainly won’t offend anyone, but the headphones this DAC is paired with have a huge impact on how the listener appreciates the overall sound. Most earbuds or headphones with an impedance of 16Ω will work well with the rhodium. As the impedance level increases, the volume starts to suffer, so don’t try to use high-impedance headphones if you like a decent dose of it

Verdict: If you’re looking for a decent DAC/amplifier to drive a pair of IEMs or wired headphones, the Periodic Rhodium is an affordable solution. It’s limited in what kind of headphones it can drive, and it won’t be able to handle any legacy digital audio file formats you might want to throw at it. Assuming you just want to listen to PCM files and using headphones with an impedance of 16Ω, you’ll be rewarded with a rich and warm sound, with enough detail to form a dynamic soundstage. Volume levels are good with low-impedance headphones, but the Rhodium is starting to have trouble driving large, higher-impedance headphones. All in all, the Periodic Rhodium is a great value if you want to use wired headphones with a smartphone that doesn’t have a headphone jack.

Prices & Availability: The Periodic Rhodium DAC/Amp is available now and costs $49 / £49 / €49 and is available on Amazon.

More info: and

Technical specifications:

  • Frequency response: 2Hz to 192kHz, +0/-3dB.
  • Dynamic range: 113dB.
  • SNR: 108 dBA wt.
  • Harmonic Distortion: <0.007%
  • Output: 31mW @ 32Ω.
  • Current consumption: 23 mA at 1 mW output.
  • Cable length 63mm.
  • Weight: 4.4g
  • Dimensions: 117 x 10.8 x 6.9mm.

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