Someday in the future we will be able to carry round and play our entire musical collection, on a device smaller than credit card. And while the hardware isn’t that miniaturised yet, the £395 ADL X1 portable DAC/headphone amplifier is certainly a big step in the right direction.
In a 6.8 by 11.8 by 1.65 cm enclosure that weighs only 147 grams, the ADL X1 houses a DAC with inputs for USB B, mini USB, iPod (both 30-pin and lightning connector via adapter cables), and analogue via a mini-stereo plug. The ADL X1 has two analogue outputs plus a Toslink digital output which doubles as one of the analogue outputs via an adapter (the same kind used on many Apple computers.) The ADL X1 supports PCM formats from 44.1/16 to 192/24. Currently it does not support DSD. It also has six small LEDs on its front panel that indicate the current sample rate.
The whole point of the X1 is to deliver optimal sonics for portable and computer audio devices. To do this you’ll need several specialised cables. A USB type A to mini B cable will allow you to charge the X1 and connect to your computer to gain access to digital music files and streaming sources from your computer. Next, if you have an iPod or iPhone you will need an iPod dock output to USB input cable. Depending on whether you have an iPod Touch, iPhone 4, or iPhone 5 the dock type will be either the 15-pin for older iDevices or the newer mini dock connector for the iPhone 5. ADL makes both kinds and includes one iDevice to USB cable as well as a type A to mini B USB cable with the X1. ADL also includes a mini-stereo to stereo single-ended RCA cable so you can attach the X1 to an analogue preamp when you are using it as an iDevice or USB DAC/PRE.
And what doesn’t the ADL X1 connect with? Well, if you had visions of using the X1 with the digital output of the Astell & Kern AK100 or AK120 or the new AK240, I’m sorry to say that since the X1 lacks a Toslink digital input, you can’t do that. You can connect the analogue output of the AK100, and any other player with an analogue output, to the analogue input of the X1. But if you want to use it as a DAC with your portable player, unless the player has a USB digital output or conforms to the Apple dock standards, you can’t use the X1 as a DAC for your portable player. Obviously you can still take advantage of the X1’s excellent headphone output and analogue line level outputs, but not its DAC section.
The ADL X1 has a Toslink digital output, which can be connected to any DAC that has a Toslink input. For owners of high quality ‘legacy’ digital to analogue convertors, using the X1 as a S/PDIF could be a very cost-effective way to add computer audio and streaming inputs to your current DAC.