Price (RRP): $3,699.95
iFi Pro iDSD features
The iFi Pro iDSD has three main functions. It is:
- a digital audio streamer,
- a digital to analogue converter, and
- a headphone amplifier.
As a DAC, it supports pretty much known digital audio format. Specifically, it supports PCM at up to 32 bits and 768kHz sampling. I haven’t been able to find music yet at more than 384kHz sampling, and they’re all demo tracks. See what I mean about covering the future?
It also supports DSD – Direct Stream Digital, the format which was first used in Sony’s Super Audio CD. The iFi Pro iDSD handles not just regular DSD64. Nor just double-speed DSD128, quad-speed DSD256, nor octa-speed DSD512. No, it goes all the way up to 16x DSD1024. Again, the highest spec test tracks I’ve got are DSD256.
Furthermore, the iFi Pro iDSD supports MQA. That’s a special format recently developed by Meridian in the UK – it also invented the fundamental lossless compression techniques used in Dolby TrueHD audio. MQA can do two things. First, it can allow higher resolution PCM audio to be packed into a stream no bigger than that used by standard resolution. Second, it carries digital “flags” which can show that the audio has been “authenticated” as original studio quality by the producers. There’s not much of this around, except on the TIDAL streaming service.
iFi Pro iDSD inputs
There are inputs for a USB 2.0/3.0 connection to a computer (Windows or Mac). This is what you’ll use for your 16x DSD files! But you can also plug in a USB memory stick or hard disk and play back content from that. Or a microSD card. Or plug in an external digital source via either coaxial or optical connection. Finally, you can feed in professional-grade AES-EBU digital audio via an XLR connector. There is also a BNC socket which allows the decoding to be clocked by an external source, something of importance in some studio contexts. You can even switch to various types of clock sources. Those last few things simply won’t be used by consumers.
A front panel display shows the signal format, sampling, input selected and processing. By “processing”, I mean you get a choice of four different filter types, or the option to convert the signal internally to DSD512 or DSD1024 before decoding.
There’s an Ethernet connections as well – the unit is after all a network streamer. But included with the iFi Pro iDSD is a Wi-Fi adaptor which can be plugged into a dedicated USB socket. The iFi Pro iDSD acts as a DLNA renderer and a network speaker for such things as Apple Airplay and Spotify Connect. The recommended app also includes support for iHeartRadio, TIDAL, Napster and Qobuz.
The iFi Pro iDSD headphone amplifier
That brings us to the headphone amplifier built into the iFi Pro iDSD. This has five outputs, three of them for headphones. One is 6.35mm – the good old-fashioned quarter inch socket, one is 3.5mm and one is 2.5mm balanced. There’s also a version of the iFi Pro iDSD with a 4.4mm balanced headphone output instead of the 2.5mm socket. This costs $300 more. At the back are RCA and balanced XLR line outputs. A switch next to those allows you to select variable output level or fixed (maximum) output level for both, at home audio or (higher) pro audio levels.
The volume control is a high-quality analogue one. It’s powered – a small remote control that operates only the volume is included. When you switch the unit on, the motor turns the volume control from the zero position back to where you last left it. It goes back to zero when you switch it off.
You can use the headphone amplifier in three modes (there’s a switch on the front): with Class A JFET solid state output, with Class A output using GE5670 valves, and with the valves but with reduced negative feedback.
Setting up the iFi Pro iDSD
With such extraordinary capabilities, you’d expect to see an impressive manual. But the manual was weirdly uninformative. For example, the unit uses a combined socket for digital audio. There’s a standard RCA socket for coaxial digital audio, but the optical socket is the hole in the middle of the RCA socket. I’ve been doing this stuff for a long time and never before have I seen this arrangement. Yet the manual doesn’t mention it.
Nor does it tell you how to install drivers on your Windows computer, nor how to set up Wi-Fi. (It isn’t all that hard. The Wi-Fi connection offers itself as an access point. You connect your phone to it and key “10.10.10.254” into a browser and then used that page to connect to your network.) There’s also a WPS button if you prefer to connect that way.
The front panel display of the iFi Pro iDSD was excellent, showing exactly what was happening with the signal. If you make a mistake in setting up your player software on a computer, you’ll soon become aware of it.
Using the iFi Pro iDSD
I was able to test the unit with PCM signals up to 384kHz sampling, and DSD up to DSD256. All of these worked perfectly when fed from my computer. Foobar2000 didn’t seem to want to work with DSD so I switched over to the much-easier-to-configure JRiver Media Center. It fed through those signals bit perfect … with the right settings. I complained about the weaknesses in the manual, but the iFi website does have several very useful documents for setting up various versions of Foobar 2000 and JRiver to properly stream DSD.