The disappearance of the jack on smartphones has proved to be a real nuisance for those of us who like to use our favorite pair of wired earbuds or headphones for listening to music. However, humans are ingenious and this has stimulated the market with the launch of quite a few USB DACs that can plug into a smartphone and drive a pair of headphones.
You can pay anything from $10 for Apple’s own DAC, all the way up to something high-end like the new Chord Mojo 2 which can bring audiophile quality music to almost any smartphone. If you want a DAC that can work with an iOS or Android, then the Periodic Audio Rhodium combined DAC and amp dongle is both affordable and a smart little performer.
The Periodic Audio Rhodium DAC is tiny and has a USB-C plug at one end and a 3.5mm stereo jack at the other. The device can either pug straight into a smartphone with a USB-C port or, if you happen to have an iPhone, the Rhodium can be used with a special Apple adapter.
The solution doesn’t look like a very elegant solution, but this is the price we must pay to use a DAC/Amp on an iPhone. Apple has its MFI (Made for iPhone) program which means manufacturers like Periodic either has to pay Apple a royalty so the Rhodium will work directly with an iPhone or the user simply has to stump up the cash for one of Apple’s Lightning to USB Camera Adapters while asking ourselves why we’re so damned loyal to those folks over there in Cupertino.
The Periodic Rhodium is a very simple device and doesn’t require a driver. Just plug it in your smartphone and then plug your favorite pair of wired headphones in the Rhodium’s jack and settle back to enjoy the music.
I tested the Rhodium out on my iMac first. The device is recognized by macOS although, rather 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 covert the digital signal fed from the phone or computer which is then fed through an analog amplifier that drives the headphones.
The Rhodium is a basic DAC and will handle basic PCM digital files. There’s no support whatsoever for MQA, DXD or DSD files, so if you do have music stored as anything but vanilla PCM like WAV or MP3, then the Rhodium is not for you. This won’t matter to most people as those other formats aren’t particularly widespread, except for MQA on TIDAL’s Masters.
As you might expect from a budget-priced headphone DAC, the Periodic Rhodium isn’t overly powerful and it won’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 level.
The Rhodium displays very low levels of distortion and a respectable signal-to-noise ratio. 113db signal to noise ratio spec as well. Power consumption is quite modest at 23mA at 1mW output. This means the Rhodium isn’t going to gobble up your smartphone’s battery and I certainly noticed that when using it with my iPhone SE 2.
Most people will use the Periodic Rhodium with their smartphone. With Android devices, there shouldn’t be any problems. It works perfectly on Android phones with OTG. However, the device is a bit fussier when it comes to iPhones or iOS devices like an iPad, you’ll need a later iPhone that’s running iOS 14.3 as a minimum to work reliably. In addition, you 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 life easy for us.
When it comes to sound, the Periodic Rhodium turned in a far better performance than I was expecting. It produces a nice and warm sound with an analog feel. I partnered it with Westone’s new Mach 10 IEMs and was blown away by the amount of detail in the music. The soundstage was well focused, while the midrange was pitched nicely forward. Overall, the tone isn’t bass-heavy, but neither is it lightweight. Treble frequencies are smooth and detailed enough to create a spatial soundstage.
It’s fair to say that the Periodic Rhodium has a wide tolerance of all genres of music and a presentation that’s relaxed and nicely civilized. It certainly won’t offend anyone but the headphones this DAC is paired with will have a lot of bearing on how the listener appreciates the overall sound. Most earbuds or headphones with an impedance of 16Ω will work fine with the Rhodium. As the impedance level increases, the volume levels begin to suffer so don’t try running high impedance headphones if you like a decent dose of
Verdict: If you’re looking for a reasonable DAC/amp to drive a pair of IEMs or wired earphones, the Periodic Rhodium is an affordable solution. It is limited in what sort of headphones it can drive plus it’s not going to be able to handle any old digital audio file format you care to throw at it. But assuming you just want to listen to PCM files and you’re using earphones with 16Ω impedance, you’ll be rewarded with a rich and warm sound laced with enough detail to form a dynamic soundstage. Volume levels are good on lower impedance earphones, but the Rhodium does start to struggle to drive large and higher-impedance headphones. All in all, the Periodic Rhodium is great value for money if you want to use wired headphones with a smartphone that has no headphone jack.
Pricing & Availability: The Periodic Rhodium DAC/Amp is available now and costs $49 / £49 / €49 and is available at Amazon.
- Frequency response: 2Hz to 192kHz, +0/-3dB.
- Dynamic range: 113dB.
- SNR: 108dB A wt.
- THD: <0.007%.
- Output: 31mW @ 32Ω.
- Power consumption: 23mA @ 1mW output.
- Cable Length 63mm.
- Weight: 4.4g.
- Dimensions: 117 x 10.8 x 6.9mm.