How does Rhodium stack up against a high-end DAC?

by DANIEL WIGGINSFebruary 25, 2022

Rhodium claims a lot - 32 bit, 384 kHz operation, 30+ mW output, almost zero THD or noise, exceptionally wide bandwidth - all in an tiny package and at $49.  So good can it be?  Well, here's some no-BS measurements against the esteemed AudioQuest Dragonfly Black DAC.  We'll let the numbers and graphs do the talking.

We connected each DAC to our test computer (a Lenovo ThinkCentre connected to our AudioPrecision test station).  Tests run at 24 bit/96 kHz since that's the max the Dragonfly Black will support.

First up, output level and bandwidth.  We set each DAC to -1 dBFS (almost full output), plugged in a set of our Titanium IEMs (a typical 32 Ohm load), connected the input channels of the AudioPrecision, and ran a test sweep:

What do we see?  Well, first off - both have very good bandwidth considering the input data rate!  Rhodium is 1 dB down at 10 Hz, the AudioQuest is still pretty flat.  And the two channels for each device are essentially identical, which indicates excellent channel matching and a stable image.

But the Rhodium has 950 mV RMS output - into a 32 Ohm load, that's 28 mW of power!  The AudioQuest?  It's got 450 mV RMS output - 6.3 mW output.  A lot lower voltage swing means a lot lower power.  

So Rhodium does, in fact, have a lot more power to drive what you want.  But how clean is that sound?  We then ran a test sweep of THD, from 10 Hz to 40 kHz.  Results are as follows:

WHOA. Across the board, Rhodium has a LOT less distortion.  In the mids and high high frequencies, Rhodium has less than 1/10th the THD as the AudioQuest.  That's a pretty serious gain!

So what do we find?

- Both have the bandwidth as claimed
- Both are portable, and work fine with most systems
- Rhodium has 4 times the measured output power
- Rhodium has lower THD everywhere, usually a LOT lower
- Rhodium is considerably smaller
- Rhodium is USB C natively (not type A like the AudioQuest), so perfect for mobile devices
- Rhodium is half the price

There you have it.  Objective numbers on our smallest DAC, Rhodium!