I just received my #Chromecast audio and couldn't resist trying it right away with headphones.
So it's perfectly capable of driving the 300 ohms +Sennheiser HD 650.
The "High Dynamic Range" seems to produce a higher quality with these headphones, the output level also gets several dB higher when activated.
(then at the maximum level, it gives a sound pressure well above the pain threshold, with surprisingly low distortion)
Subjectively it also sounds rather good, which is not the case for every equipment with the HD 650: with its mostly neutral frequency response and low distortion it becomes a lot easier to tell the difference.
A very crude quick test via lossily compressed test samples seem to indicate the presence of some resampling artifacts on 44.1kHz content, none for 48 kHz (needs verification)
Still, it could probably serve as cheap headphones DAC / amplifier for special uses for headphones notoriously difficult to drive, replacing favorably a few smartphones or laptops' audio output.
But please don't take my word on it quite yet, I'll test with more headphones / earphones and also complete measurements.
I might have to write some new code for that however in order to cast lossless audio – apps I found so far use lossy transcoding which is not necessary.
Google confirmed that resampling to 48kHz would be corrected in a software update.
+Jeff Mudrick Oh nice, source?
Google Chromecast support Forum (Jackye)
+Jeff Mudrick thank you very much, I'll check that out 😉
October 9: "Hi Everyone,
Chromecast Audio is currently resampling content to 48KHz over optical. This is a know issue that will be fixed in the next update. Thanks for your patience!"
https://productforums.google.com/forum/m/?hl=en-GB#!category-topic/chromecast/k6JZRM2TUco
+Jeff Mudrick I see, I was speaking about the analog output.
Which means they probably resample everything to 48k and run the DAC at this fixed rate as well (needs verification)
Others have indicated that's the case.
+Jeff Mudrick I found the thread you mentioned on https://productforums.google.com/forum/#!forum/chromecast
Reading many threads now, some people say strange things or have really weird issues 😀
Resampling issue aside it's been working great for me using Toslink output for Google Play Music, or Tidal via BubbleUpNp.
Based on your write up, I decided to order one. Thanks! ping ->+Peter Nguyen
I tried with the very sensitive in-ears Sure SE535:
– you can hear hiss
– you can hear quantization artifacts at lowest volumes.
I suspect the mixing and DAC are running at 48/16 at the moment.
It's not bad at driving low sensitivity or high impedance headphones because of the 2V output via the DRV632, however it's weak for what's very sensitive.
Most smartphones from recent generations are better at that already.
But it is fine for what it's supposed to do anyway which is outputting at 2Vrms line-out level into another audio equipment 😛
24-bit mixing and output would still be desirable for software volume however.
So you give the akm dac a thumbs up?
Couldn't remember where I read akm before until I finally found the e-mu 0404 had used it.
The hiss shouldn't be a problem with the higher input impedance on the speakers. (10 kOhm on mine)
Very tempted to pick one up just because.
+Daniel Goller It'll be better once they set the sampling rate to the input source as they said.
But yeah pretty cool device for the price, good sounding and an interesting tool to think about network audio in different ways 🙂
+François Simond awesome that you do serious audio analysis as well to visual analysis! I wonder how you can hear and recognise upsampling aliasing artifacts? Can you please explain so that university level maths are not required to understand ☺
+Viljo Viitanen I didn't complete measurements yet on this one, but trained ears with low distortion headphones allow to identify all sort of audio quality issues 😉
For resampling artifacts I'm using the famous 44.1 kHz udial sample and a 48 kHz version of it I made using SoX.
This sample also enables you to hear and detect audio jitter in some scenarios, this is how I started with Voodoo Sound years ago ☺
First impression is it sounds rather good if you use the power supply.
If you try to save on Wall outlets in use you get to hear everything going on on that bus.
What do they use when you don't opt-in to the high dynamic range in settings?
What do they use if you do?
+Daniel Goller I'll try to guess later with measurements, if the output path is the same with just the output level changed.
While it's nice to not have to have the music app running on phone while chromecast plays music.
It's even nicer when it does, then my pebble sees the tracks and I can skip around from my wrist.
+Daniel Goller Yes my android wear watch does too, getting the controls from the paired phone with the album art and everything, it's pretty cool!