Periodic Audio Rhodium Review

Periodic Audio Rhodium Review

30 June 2021 0 By Petros Laskis

Better than the rest

Pros: – Natural , balanced and enjoyable
– Minimal footprint
– Extremely lightweight
– Durable
– Plug and play
– Made in USA

Cons: – Power output limited to 1 Vrms
– iOS is not well supported
– No DSD and MQA

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.

IMG_20210629_174944~2.jpg

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

IMG_20210629_175059~2.jpg

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.

IMG_20210629_175345~2.jpg

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).

IMG_20210629_175920~2.jpg

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.

IMG_20210629_175545~2.jpg

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.

IMG_20210702_171340~2.jpg

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.

IMG_20210701_175845~2.jpg

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