iFi Audio’s Nano iONE is an interesting device that can operate both as an MQA & DSD capable DAC, with USB, S/PDIF and Bluetooth inputs, as well as a “digital-to-digital converter” (DDC) allowing Bluetooth or USB input and S/PDIF output (to feed other DACs).
This is the spot to discuss this multi-function device.
I picked up one of these little units at the start of the week with my primary use-case being to add a Bluetooth input to a little rig I put together for my “day job” office (since I seem to be there more than usual of late). I’ll talk more about that rig elsewhere.
For here … what I needed was a way to take a Bluetooth input, with at least AAC and aptX support, and get a decent S/PDIF coax output to feed an entirely different DAC. I have other products that can do that via an optical connection, from USB, but those were either limited to the SBC protocol, didn’t have a COAX output or were simply not cost effective for this application.
In getting this, setting it up, and playing with it, there are few things to note:
For one, on the firmware it was supplied with MQA support and DSD are enabled, but the S/PDIF output is NOT (normally both the Bluetooth and USB inputs result in S/PDIF output as well as output from the DAC itself)! As that was the primary use-case for me, the first task was to find the right firmware to get the functionality I needed. This wasn’t hard, but iFi Audio’s documentation about which firmware revision does what isn’t as clear as it could be. So let’s address that first:
Firmware 5.2 has no MQA support, but does support S/PDIF output from both Bluetooth and USB inputs as well. Allows 384 kHz PCM and DSD256 (4x DSD) replay.
Firmware 5.3 (what it was supplied with), disables all S/PDIF output, but adds MQA Renderer support (you’ll need your player to do the first MQA unfold, as with things like the iFi Nano iDSD BL).
Firmware 5.3C enables S/PDIF output for Bluetooth input, but does not support S/PDIF output for the USB input, has MQA Renderer support, and replaces the standard minimum-phase filter with iFi’s “GTO” (Gibbs Transient Optimized) filter.
So, in most cases, unless you want to use it as an USB->S/PDIF converter only (and I can think of cheaper and better ways to do that if that’s all you need), you’ll want firmware 5.3C on your unit. The update process is quick and simple, and the firmware etc. can be found here.
More thoughts to follow …
While I bought this thing as a Bluetooth to S/PDIF (COAX) converter, since I have it I figured I might as well actually give it a listen as both a Bluetooth and USB DAC as well.
The firmware version affects both audible and measured performance with USB input here, so pay attention to that.
Broadly speaking it’s not very far from the iFi Nano iDSD Black Label when fed over USB with output into an external amplifier using the iONE’s RCA outputs and the iDSD’s 3.5mm Line Out. When used purely as DACs, they have a very similar signature and technicalities and it is really only the presence of some low-level edginess/hash (which was firmware-dependent) with the iONE that puts it behind the iDSD.
That edginess/hash was NOT present using firmware 5.2 nor 5.3C. Also, if I applied digital volume control ahead of feeding the signal to the iONE, and reduced the output level to a maximum of -1 dBFS (normally this would be 0 dBFS), then this edginess goes away. Unless you need USB -> S/PDIF conversion here, this is a non-issue.
I suspect any differences in final sound, on the 5.3C firmware, are down to the output stages of the units rather than anything else… But the iDSD Black Label is definitely ahead here. We’re not talking major differences. Maybe 1 or 2% at most. But if you don’t need/want the Bluetooth functionality, the iDSD is the better sounding unit, with the bonus that it includes a very nice headphone output and IEMatch for IEMs, as well as a built in battery for use on the go.
The most obvious differences between using the iONE with a lossless USB source vs. via Bluetooth (both using an identical 16/44.1 FLAC source) are that the Bluetooth connection loses some detail, exhibits a slight bass emphasis (more in terms of a little bloom than in level), and that there is some softening of transients.
It is an inoffensive difference, and isn’t plagued by harshness or grain. It’s just a bit smoothed off vs. the USB input.
This is a fairly easy one; AAC sounds marginally better than aptX here. Both are notably better than SBC, but AAC just takes the cake. If your source device lets you conveniently choose your protocol, then I would go for AAC personally, but the difference is not as big as the change going from USB to Bluetooth in the first place.
