Periodic Audio Rh

Package is simple and eco-friendly inside is the DAC and a USB C to A adapter. The cable is fixed and non-removable for this price this is acceptable, and it's made from a durable nylon braided cable so it should last a long time if treated well.


Frequency Response

2 Hz to 192 kHz, +0/-3 dB

Dynamic Range

113 dB

SNR

108 dB A wt.

THD

Less than 0.007%

Continuous Output (RMS)

31 mW @ 32 Ohms - Per Channel

Dynamic Power Output (Peak)

62 mW @ 32 Ohms - Per Channel

Physical Properties

Cable Length

63mm

Mass

4.4 grams

Operational Temperature

-20 to +50° C

Operational Humidity

0 - 95%

Retention Force

1.8 Newtons

Overall Length

117 mm

Max Width

10.8 mm

Max Thickness

6.9 mm

Material Properties

Melting Point

2237 Kelvin

Speed of Sound

4700 meters per second

Young's Modulus

380 Gigapascals

Brinell Hardness

1100 Megapascals

The sound: The DAC presents rather neutral there is a little hint of warmth in the lower mids but it's hard to pinpoint such thing, as so many factors and devices differ ultimately the Rh presents with a fair amount of clarity and details, it has a smooth enjoyable sound.

Conclusion: The Periodic Rh is energy efficient and easy to use and provided a noticeable increase in volume and clarity on many devices. It is fairly low powered so no full sized or higher than 32-Ohm should be considered, and I would recommend lower for optimal use 18-22. Still this easy to use and carry and doesn't cost too much so I think it would be good paired with an amplifier for daily use.

Periodic Audio Rhodium Dongle DAC - Diminutive Music Shaper



Priced at 49 USD, Rhodium is one of the smallest and discreet dongle DAC/AMPs made to date, with 32Bit / 384 kHz decoding abilities. It features a fairly low power output, of 31mW, so it will be suited for usage with IEMS and portable headphones.

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Introduction

Periodic Audio is a company that offers excellent performance for their IEMS, but also good technical background information. They created some really unique products over the years, and I will be reviewing the upcoming Periodic Audio IEMs with detachable cables in the near future as well. The company has good support for their customers, and is in the list of recommended companies for me.



It should be noted that I have absolutely no affiliation with Periodic Audio. I'd like to thank Periodic Audio for providing the sample for this review. This review reflects my personal experience with Periodic Audio Rhodium Dongle Dac AMP. Every opinion expressed is mine and I stand by it. The purpose of this review is to help those interested in Periodic Audio Rhodium find their next music companion.



Packaging

First things first, let's get the packaging out of the way:











The package of the Rhodium is fairly simple, and it includes the dongle DAC/AMP, and a typeA to typeC adapter. This is the smallest dongle I have reviewed to date, and the lightest one, so the package being tiny is no problem, especially for the price. The package is vertical and looks a bit like what you'd see for a multivitamin supplement, so make sure to not lose the Rhodium package when handling it, or your grandfather may become more musical than he ever was.



Build Quality/Aesthetics/Features

To use Rhodium, you just plug it in either your smartphone, or your computer, and it basically works. It is an active DAC chip, so it has its own DAC / AMPs and capacitors, working with basically all the smartphones and computers I tried it with. No additional drivers are needed for windows 10 at the moment of writing today's full written review.



The chips inside Rhodium are more of a mystery, but they have been identified as Realtek ALC5686 SoC, a component that has been used with other high-end audio capacitors in computer design. Rhodium is a TRS device, single ended, and will work well for smartphones that have no Type-C port, or computers / laptops where the audio jack has a poor quality (most of them do).



We have support for PCM signals only, with PCM support up to 384 kHz / 32 Bit, and while I like to push new technology like DSD and DXD, and MQA, I personally do not use them very much, since most of my music is not available in those exotic formats. In fact, almost my entire library is made of redbook flac files that I ripped myself, and most of those CDs aren't even available for purchase anymore, let alone in MQA or exotic formats. While you can set up Foobar2000 and other players to decode DSD and deliver it via PCM, for the vast majority of users Rhodium will be adequate, and for those who need MQA and DSD, there are alternatives for a higher price.



Rhodium has a rather low power output, and with 31mW of power, it will drive mostly IEMs and portable headphones, plus the best sound can be found at average listening levels, rather than loud. The low 0.007% distortion, and high 113 dB of signal to noise ratio are excellent, for a unit that is so low. The power consumption of Rhodium is incredibly low, and it does not change the battery life of my smartphone in any way, with a 23mA constant power draw. It weights 4.4 grams, being one of the lightest DAC/AMP dongles I tested to date.



Sound Quality

The sonic performance of Rhodium is good, and it has a pleasant, warm signature, with some midrange forwardness, but good background nuance and detail, all within a flat frequency response. To take today's impressions about the Rhodium, I've been using exclusively IEMs, and those include Tin T3 Plus, Dunu Falcon Pro, IMR Audio Ozar, Campfire Mammoth, Earsonics Corsa and QoA Queen Of Audio Adonis.



The bass of Rhodium has a flat presentation with lesser impact, and this is one of the places where you notice the lower power it delivers, but the bass has good nuance and definition. The bass has good warmth in the upper bass, and you can totally listen to EDM, Pop and Electronic with Rhodium, but the best performance is with Jazz, Country and Acoustic music, where the overall warmth and pleasing tonality creates a really relaxing listening experience. The overall speed of the bass is slow, which means long note decay and slower impact.


The midrange continues this fashion, and it is presented smoothly, clean, and with good timbre and pitch. The midrange is slightly forward, with a good amount of detail, and Rhodium is surprisingly wide for the signature and size it has, having a good depth and width, presenting music in a very 3D style. Despite the rather low power it has, the dynamics are great, and Rhodium provides a good depth and distance between you and the singers from your favorite songs. I would call the midrange organic in nature, and it is a breath of fresh air, compared to brighter and more peppy DACs / dongles like Beam 2 from Audirect.

The treble of Rhodium rolls gently, and has a lower presence, leading to a smooth and relaxing top end, with a good amount of clarity and air. The sound is well controlled even at high volumes, and it can push some high decibels into the IEMs I used for testing it, plus it has low background noise and hissing. Rhodium pairs well with brighter IEMs, and with IEMS that are easy to drive, like Tin T5, or FiiO FH5S, and even dd hifi Janus, as it stays controlled and relaxing with those.



Value and Conclusion

For the 49 USD price point, Rhodium is an excellent dongle / dac / amp purchase and it provides a natural, refined and relaxing sound, with enough power for IEMS and portables. It has one of the lowest power draws of all dac/amps, and it will be the perfect partner for long trips, especially if you don't have access to power, and want to enjoy your music for long hours. If your smartphone does not have a 3.5mm single ended jack, then Rhodium will be the perfect partner, and if it does, Rhodium will sound smoother, warmer and more relaxed than your smartphone, so it will still be an improvement, especially if you're using bright and shouty Chifi IEMS.



At the end of today's review, Periodic Audio Rhodium is one of the most relaxed, smoothest and most organic sounding dongle DAC/AMPs, and it most certainly is one of the most energy efficient ones, and a fully recommended purchase if you're looking for a pleasing and warm sound.



Specifications

• Frequency Response - 2 Hz to 192 kHz, +0/-3 dB
• Dynamic Range - 113 dB
• SNR - 108 dB A wt.
• THD - Less than 0.007%
• Output Power - 31mW @ 32 Ohms
• Current Consumption - 23mA @ 1mW output
• Cable Length - 63mm
• Weight - 4.4 grams
• Operational Temperature - -20 to +50° C
• Operational Humidity - 0-95% Relative Humidity
• Overall Length - 117 mm
• Max Width - 10.8 mm
• Max Thickness - 6.9 mm

disclaimer: The Periodic Audio Rhodium was provided for review by Periodic Audio. I have no financial interest in Periodic, nor have I received any payment beyond the test unit itself for this review. If you have an interest in learning more about Periodic Audio products, See their website and Facebook. Right now Periodic has a promotion for Father’s day that includes a free Rhodium with purchase of a Carbon in-ear and Nickel Amp.

Packaging:
Packaging is very simple with a white card stock box with black lettering and the periodic table style layout we have come to expect from PA. Inside the box, we find the dongle itself and a USB type-C to type-A adapter. No USB to lightning adapter is provided and the Periodic website is quick to note that even with the camera kit, the Rhodium may not work with apple devices so this is best used for android, windows, Linux, and mac-OS where it is detected by plug and play and works well.




Build:
The dongle itself is tiny and one would be forgiven for assuming there was no dac in it as it seems there simply is not space to accommodate one. At the south end, we have a USB type C connector in a black polymer housing with a short strain relief then at the opposite end of the cloth wrapped cable we have a a round housing for the 3.5mm port. Again a short strain relief is provided. Overall length is just short of five inches with the USB connecting being just under 1 inch in length, three eighths of an inch wide, and roughly one quarter inch thick. The 3.5 port is also roughly one inch long with a quarter inch diameter. As suggested, this leaves little room for anything internally as space is certainly at a premium. The good news is the dongle weighs almost nothing and certainly wont be something you have to contend with when on the go.





Internals:
Periodic doesn’t list the chip used inside the Rhodium but a little digging using android and linux USB tools identifies the chip as either a Realtek ALC4042 or ALC4050. I have attached both datasheets for those interested in more details. Regardless of which of these two codecs is in use, the dongle supports up to 32bit / 384kHz PCM but does not support DSD or MQA which is a bit limiting by today’s standards. The specs list 31mW @32Ω which makes this best reserved for in-ears or extremely efficient headphones. I tried the Rhodium with several different models just to see how far I could push and definitely found some limits. Beyerdynamic’s 600Ω DT990 is definitely out as the Rhodium simply doesn’t have enough usable volume range for this. The HD6xx was better but still lacked enough volume range to really be useful. If I maxed out the volume, I could reach a comfortable listening level, but it had no headroom left for a crescendo at that point. With iems it fared a good bit better with the exception of the TinAudio P1 and the Tri I3 where it again struggled to have enough power to push them to full capability. Periodic markets the Rhodium as a pre-amp rather than a DAC/Amp which is probably a good way to think of it as alone it lacks the potency to drive all but the most sensitive of in ears. On the plus side, there was no his with my Magaosi K5 which is notoriously sensitive so it pairs well in those instances where more power is a drawback.


Sound:
It can be hard to determine exactly what any dac/amp brings to the mix as so much is dependent on source and headphones in use. The Rhodium does have good detail and clarity, but lacks some impact in the lows especially when paired with anything it struggles to drive. I found the Magaosi K5 paired well and had good detail retrieval, nice crisp mids, and acceptable bass (it never has a ton here anyway), but as I moved to harder to drive models, it quickly became evident that the Rhodium is meant as a pre-amp and not as a dac/amp by itself. When used with an amp following and thought of as a dac only, the Rhodium does a good job of staying neutral and rendering detail well.


Conclusions:
With makers coming out of the woodwork to provide USB to 3.5mm jack dongles for the cellphone market, it is no surprise that Periodic felt the need to have a model of their own to complement their in-ear offerings. The Rhodium offers a good level of detail and a quality build and does pair well with the Beryllium and Carbon models and the low output power does mean it helps conserve your phone battery which is a good thing if your in-ears don’t need additional power. The downside to that limited output is it either needs to be paired with an amp or doesn’t have the potency to drive over-ear models or high impedance / low sensitivity ear buds. This makes it a niche player at best as too many other dongles offer those features at nearly the same price. Periodic does market the the Rhodium as a pre-amp and even goes so far as to package the Rhodium with the Nickel amplifier and Carbon in ear as a kit and this is likely the best use case for the Rhodium as it functions well as a dac but needs a potent amplifier to complement it.

The Rhodium DAC was kindly provided by Periodic Audio free of charge and doesn't need to be returned.
As always this is my honest and subjective evaluation of it.
The price is $49 and you can buy it from Periodic Audio

Introduction

Rhodium is a chemical element with the symbol Rh and atomic number 45.
It is an extraordinarily rare, silvery-white, hard, corrosion-resistant…..

Hey , keep reading , this is not a scientific article , it's all about the Rhodium from Periodic Audio , a tiny USB DAC/amp cable.

Rhodium is a mobile high resolution audio DAC/Preamp/Amp that connects to any USB type C port and improves audio quality by supporting 32bit/384kHz sample rates and providing an amplified output stage for wired headphones.



Physical specifications

The Rhodium is not like your average USB dongle as it is more like a short USB type C cable with a slim embedded (3.5mm) headphone jack.
Literally a short extension of your earphone cable that doesn't occupy any space or hang loose from the phone but rather it is plugged in and left forgotten.
It is barely 63mm long from one end to the other and weighs just 4.4grams.

The two plugs are joined together with a proprietary high-strand OFC wire with polyethylene woven jacket and they are reinforced with molded aluminum shells for extra durability.

Build quality and assembly are very good and the Rhodium cable looks quite durable and tough.

Rhodium is made in USA



Technical specifications

The base chip that is responsible for the digital to analog conversion and amplification duties is a humble Realtek ALC5686 but implemented with clever engineering and carefully selected components.

According to Periodic Audio , specially selected audio-grade caps of C0G tolerance in all audio pathways, high-speed, high-stability X7Rs for all power supply bypasses , results in a 10 dB lower noise and 1/2 the distortion of any competing product.

Capacitors and components were chosen very carefully and based upon the dynamic voltage and current demands, so that the capacitance was as constant as possible under real-world loads.

This implementation eliminates voltage "pumping" from current spikes, which can lead to increased noise and distortion.
This meant evaluating lots of caps of different sizes to ensure stability under real world operation.

The Rhodium boasts pretty incredible specs for it's size like 113 dB of Dynamic range , 108dB SNR and THD less than 0.007%.

The output voltage is a mere 1V rms which translates into 31mW / 32 Ohms and 25mW / 16 Ohms.

Not much but let's not forget that this is a bare bones entry level USB DAC cable to use with sensitive iems for everyday casual listening.

A lot of other much more expensive competitors boast the same specs like the Audioquest Dragonfly Black which outputs 1.2 Vrms.

Power output may be limited but in exchange we get minimal power consumption of just 23mW (1mW of output) so the Rhodium isn't going to drain your phone battery.



The Rhodium is compatible with Windows , Android and iOS without the need to install drivers

But according to Periodic Audio iOS devices aren't well supported.
They have confirmed that a 4th gen iPad, running iOS 14.3 works, but most iOS devices would require use of the Apple Camera adapter, and even then, success is not guaranteed.

A few words from Mr. Dan Wiggins

At this point of the review and before our listening impressions we feel like quoting Mr. Dan Wiggins who talks measurements and performance of the Rhodium.

"So, to sum up, Rhodium:

- can output 1 Vrms into a 32 Ohm load
- will generate 3 mW into a 300 Ohm load, and 30+ mW into a 32 Ohm load
- will have < 0.008% THD @ 1 kHz @ 30 mW output (1Vrms into 32 Ohms)
- has even better performance at typical 1 mW output listening levels
- was designed so that tradeoffs benefitted typical listening levels rather than rarely-used full output levels
- is not optimal for high impedance, large/inefficient cans
- is extremely portable

Oh, lastly: we use the ALC5686, not the 4050 as shown in a previous picture. It's a bigger package (6mm x 6.5mm) but with finer pitched pins. We also have a higher tolerance oscillator, and selected every cap in the system with an eye towards superior performance in the small package, but when tradeoffs arose we chose to give priority to typical listening levels (-25 dBFS to -10 dBFS) rather than full/max output (0 dBFS)"

Dan Wiggins - Period Audio.

All measurements are available at Periodic Audio website.

Sound impressions

In order to evaluate the Rhodium we have mostly used , easy to drive , entry level earphones such as Meze 12 classics (review) , FiiO FD1 (review) and MoonDrop Aria (review).



The Rhodium is musical and thoroughly engaging without any coloration and also sounds surprisingly well extended to both ends of the audio band.

It is accurate and transparent with astonishing levels of clarity while it is a lot more resolving and detailed than someone would expect at this price point.

A cohesive and balanced sound signature with bass that is deep enough and not too lean while staying tight and controlled.
Mids feel spacious and well rounded with a natural timbre and fine articulation while highs although inoffensive are extended with plenty of energy to add some sparkle to the mix and resolve good amounts of detail.
When not pushed to its limits, the Rhodium sounds quite dynamic, while the soundstage is airy and well expanded with a good sense of realism.



The Rhodium is meant to be paired with sensitive and easy to drive earphones.
So we must be realistic regarding it's capabilities and don't expect it to run HiFiMan Sundara or complain about Sennheiser HD650 not getting loud enough.

Compared to the usual one chip (more expensive competitors) like the iBasso DC03 , the Zoorlo Ztella or the Shanling UA1 - to name a few - you are not going to miss anything in sound quality and the only real difference lies into the power output.



Periodic Audio Nickel

Do you need a little more juice for power hungry headphones when you are traveling or back home?

No problem as the Rhodium is an excellent preamp that connects to any analog amplifier like the Nickel from Periodic Audio.



The Nickel is a miniature , yet very powerful , battery powered amplifier , very simple to use, which can output a whooping 250 mW at 32 Ohm loads.

It is quite expensive for the given size but well worth it because it sounds superb while fits inside the smallest pockets.

The Nickel is a real masterpiece but hey this is another story…
(warning - upcoming review soon to be published)

At the end

The Rhodium is not just another mass-produced uninspiring budget DAC/amp cable.
It is rather an engineering lesson in minimalism or how to design something exceptional starting with the most simple parts.

As long as we respect the intended use and don't expect miracles from it (like a reviewer who tested it with Sennheiser HD650 and found it lacking…) then the Rhodium is a very good sounding DAC/amp cable with the most minimal footprint that is going to immediately upgrade your everyday listening experience.
For $49 it is a no brainer and highly recommended.

Test playlist

Copyright - Laskis Petros 2021

Summary​

Yes, the Dongle DAC/Amp market is super crowded right now, but that hasn’t stopped Periodic Audio from dropping their own branded dongle DAC at a reasonable price of $49.

It’s called the Periodic Audio Rhodium DAC, and it has 32bit/384kHz high-res PCM decoding, along with 30 mW of power to boost their earphones. Periodic is all about mobile hi-fi, so they made Rhodium extra light and slim for use on the go, but that also means it doesn’t have as much juice as its competitors.

That’s said, I love the streamlined design for use with a smartphone, as it isn’t bulky and doesn’t flop around.

There’s no DSD decoding, which is not a big deal since there aren’t many people playing DSD on their mobile phones. I would’ve liked to see an LED indicator for sample rate, however.



Overall, it’s a clean-sounding DAC/Amp with excellent natural detail and separation for the price, but don’t expect to fire up any power-hungry headphones with it.

If you’re a Periodic fan, and you’re picking up (or already own) their earphones, the Rhodium will be a good match aesthetically, ergonomically, and sound-wise (Which makes sense because that’s what it’s designed for). It’s a no-brainer for the price.

Outside of that, you need to weigh the beautifully smooth sound and compact dimensions against what type of headphones/earphones you plan to use and how much power you need.


Disclaimer: The Periodic Audio Rhodium DAC was sent to us by the manufacturer in exchange for our honest review.

Build/Features​

If you’re not familiar with Periodic Audio, they’re a cool brand that markets various in-ear headphones and accessories with names pulled from the Periodic Table. Their mission is to be “a mobile-first Hi-Fi company whose primary value proposition was high-quality audio performance.”

To that end, they primarily manufacture simple to use, comfortable to wear IEMs (earphones) that have excellent sound quality.

They also have a portable headphone amp called Nickel, which I reviewed back in 2019, and I was astonished at how powerful and clean it was for its size. It’s about the size of a 9-volt battery and supplies 250 mW into 32 Ohms.

While that is impressive, it’s analog-only, so to get the best performance, you need to pair it with a DAC, or at least a source with a good DAC installed.





That’s where Periodic Audio’s latest product, the Rhodium DAC, comes in. It’s a USB DAC/headphone amp capable of high-res 32bit/384kHz PCM decoding, as well as 30 mW power output (or 1Vrms) into 32 Ohms.

It’s not advertised, but word on the street is they are using a Realtek DAC/Amp chip. As usual, Periodic shows their work by posting measurement charts on the website.

There's no MQA, and I wouldn’t expect it at this price, but the lack of DSD decoding is a bummer.

The Rhodium is a very slim dongle with USB-C on one end and a 3.5mm headphone jack on the other. It’s quite similar in size to the dongles that are included with many smartphones today.

That’s by design, as Periodic wanted it to conform to their “mobile-first” ethos, meaning it should be well suited for use on the go. They definitely got that right, as it is the perfect length and width to stay out of the way as you walk around.




The stiff braided cable also keeps it from flopping all over the place, which I like a lot.

However, that compact size does come at a cost. That’s because, at 30mw, Rhodium is not the most powerful dongle style DAC/amp out there. Some around the same price have double the output power, but they are larger and more cumbersome to use.

Since Rhodium is primarily intended for use with sensitive earphones (the type Periodic sells), they prioritize sound quality over class-leading power output.

They claim their high-quality oscillators and specially selected capacitors provide superior performance to the dongles included with smartphones.

Even though this DAC/Amp is mainly intended for mobile use, it comes with a USB-C to USB-A adapter, which makes it also suited for use with laptops.





While it won’t give you too much of a power upgrade, it should give you a little upgrade in sound quality over the laptop sound card.

Listening To The Periodic Audio Rhodium Dac Amp​

For my testing, I started with the Rhodium and the Periodic Audio Carbon IEM($399, sold sep.) connected to my Moto G Power test phone. I played hi-res files from Qobuz via the UAPP (USB Audio Player Pro) app.

In terms of sound quality, I have to say I liked the Rhodium quite a bit. I’m really sensitive to edgy-sounding dacs, and unfortunately, many manufacturers boost the treble on budget gear to create some “detail.”

I’m happy to say that wasn’t the case here, as the Rhodium had a smooth treble but not so smooth as to blunt all the air present in the recording. The mids were natural and sweet, nicely presenting the texture of strings and other instruments. The Bass was deep and controlled the way I like it.

The extension was a little rolled off on either end of the audioband, but not overly so. It actually gave this DAC/Amp an organic “tubey” sound which was pretty nice. If you like a whole lot of sparkle up top, you may find the Rhodium to be a little dull.





As far as separation and layering are concerned, this DAC Amp combo did a good job, especially for the price point.

I listened to the new 24/192 Christian McBride EP, “The Q Sessions” on Qobuz, and I was delighted at how it was able to play the songs with depth.

I was able to hear the instruments somewhat in their own little bubbles and certain instruments layered behind the others. It’s amazing what these little chip DACs can achieve today.

Of course, the Rhodium will not give you the detail or separation of some of the $100-$200 models out there, but at $50, it makes a nice little upgrade for the USB-C to 3.5mm dongles that come with phones nowadays.





As far as power is concerned, like I said earlier, Rhodium’s power output was on the low side. It drove high-sensitivity Over-Ear headphones like the Focal Elear, but I had to turn the volume in UAPP up to about 80% of maximum.

Even at 80% volume, it drove the Elear with full dynamics, and the sound quality was good. So you can use Rhodium with some full-size headphones in a pinch, but you won’t have a lot of headroom.

The Wrap Up​

The Periodic Audio Rhodium is a nice DAC Amp combo for those looking to upgrade the sound coming from their smartphone, especially if you’re doing a combo with the Periodic IEMs. It's perfect for that.

I like the lightweight, sleek build, as well as the natural, relatively detailed sound. I just wish it had a little more juice for full-sized headphones.

This review was originally posted at https://hifitrends.com/

Buy one. Listen to it. Sounds terrific. Can it compete with Dragonfly Black? You bet. Blue or Red? Don't know, don't care. I paid $50 for this gizmo and it rocks. These people from Periodic Audio work hard and bring us affordable, dynamic products. Support them! I have two sets of their IEM's and now this Rhodium. A simple, effective, affordable, portable rig. Peace out!