My Chromecast Audio also arrived today and I've had an opportunity to put it through its paces. Classic piece of packaging and minimal instructions as is usual with Chromecast devices. For the initial set-up I plugged it into a cheap powered Bluetooth speaker with a Aux input. The Chromecast Audio uses the same Control App to set it up as the Video variety. The unit detected my 5G Wi-Fi network pretty quickly. No reception difficulties as it is situated right next to the modem. Set up appears next to the two Chromecast videos I already use. There is an invitation to 'name' the device and then enter your internet code. This was followed by a short delay whilst an upgrading was loaded. Job done.
The unit comes with a very short yellow 3.5mm stereo lead, and a power supply. When operating the 3.5mm socket is illuminated by a red light (is this the optical output?). The case also has a small white light which, when steady, indicates all is connected. There is also has a small button which, if it follows the normal pattern is a re-set button. Usually a 30sec push does the trick. The unit runs slightly warm, but nothing alarming.
I had no need to download any other apps as I already had a number of audio based apps on my phone & tablet. These included Google Play, Tune-in Radio and All Cast. Even with my cheap (Tesco) speaker the sound was a noticeable improvement over its normal Bluetooth connection. I already had a 3.5mm to RCA lead to plug into my Onkyo TX-SR576 amp (CD input socket). Couldn't resist plugging in a earpiece directly into the Chromecast output socket. No problem, it worked, but I don't recommend it without knowing the exact impedance matching.
I am not one for streaming as I prefer to buy CDs or iTunes downloads and store them as MP3s on my phone or tablet. Usually at 256kbs. I played a few sample tracks of various genres and again there was a noticeable improvement over Bluetooth. The unit is very responsive to instructions.
Here's a tip. Click on the cogwheel on the Chrome Audio indicator section, under Devices, on your phone (which incidentally shows the cover photo of the album you are playing) and you will display the 'Device Info'. Scroll down and switch on 'High Dynamic Range' (For AVRs and Hi-Fi systems) The effect is very obvious and the sound becomes much more 'punchy and dynamic'. There is also a facility to turn off the 'plop' sound that indicates a connection and a volume change. The device also has a Guest Mode which allows others to easily opt into your system.
Whilst in this menu check out the 'Offers' button. Two were available. 90 days of Google Play Music and 3 months of Deezeer Premium+. Taking these offers is worth more than cost price of the Chromecast Audio. Take up these offers and you've got the Chromecast free! The Chromecast 'Get Apps' option, in addition, offers links to Spotify, Vevo (although this is a Video app!) & Musicmatch. There seems no filter in place to offer you 'audio only' apps. Obviously video ones will not work.
Used Tune-in and streamed BBC Radio 3 which is usually a higher bit rate than most streamed stations. Sounded really good and clean from a live concert.
Very satisfied with £30 well spent. The Google Play Music App will not play side loaded prerecorded MP3 tracks from your memory, but plenty of other Apps such as AllCast and Sony Music will do.
I'll be interested to see what others think and how the AK4430ET DAC matches up technically to other players. A multi-room facility is promised in the future which puts it as a very low cost contender to the likes of Sonus. I would also like to know what other formats it can manage. Happily it fulfills my requirements.
Addendum: Now connected by an optical lead, cost about £5, and sounds even better. Don't underestimate this product because it's only £30.