Review and Measurements of Chromecast Audio Digital Output

[SMc]

I did an inadvertent self-test for the CCA level when I selected the lower output level. Good lord! I thought I'd found Gary Larson's 'Suck' button!

http://i168.photobucket.com/albums/u165/myxology/UBP Stuff/far-side-turn-up-the-suck-knob-soun.jpg

Fortunately, turning up the volume to my normal levels restored the missing 'quality.'

 

[GGroch]

Thanks for the links.........As far as being better, there are DACs featured here that measure better than the CCA. Are you saying that those differences are not audible therefore "should not objectively sound better"?........Again, this was not a blind test. I doubt I can tell the difference between the Modi 2 Uber and CCA analog in one. But I think I can do it with the E30 v CCA analog. I'll ask my wife to help me with this later......But thanks for your comment!

You're welcome! I am glad you found testing fun. Let me answer your questions the best I am able.

1. RE: Other DACs measuring better. The CCA was fed a 16 bit 44k signal on Amir's test resulting in 91.3 db S/N. 96 dB is the theoretical maximum for a 16/44k signal. Archimago measured 97 dB which is perfect. DACs cannot do better than 16 bit resolution on a 16 bit signal. On a 24/48 Plex signal Archimago measured 105.4. While you could theoretically do better, Amir said in a recent video that 95dB is essentially perfect in terms of audibility. The CCA can handle 24/96 if your streamer supports it. Other DACs Amir measures that are better are not measured using a 16/44kHz signal, where their performance would be very close to the CCA. So:

2. Other DACs should not sound better in a blind listening test. Amir's recent very long video on Listening tests is excellent on this point. He describes an online A/B/X test posted by Archimago to see if anyone could hear the difference between 16 bit (96dB max S/N) and 24 bit (theoretically over 120 dB). No one could.....except Amir. But Amir cheated sort of, see the video. This relates to CCA because if we cannot hear the difference between 16 and 24 bits in blind tests except in extremely limited circumstance with very rapid switching of a targeted 2 second clip (see Amir's cheat)...then there is no way we can hear the differences between DACs of this quality in a blind test. Blind tests make us very humble.

3. But, we will absolutely hear the difference in sighted tests. There is no way to overcome cognitive bias. The differences we hear can be huge as nerone noticed above. Being an experienced audiophile, having a highly resolving system and even exceptional ears makes absolutely no difference. Cognitive bias overwhelms everything else, it is how our brains work. In Amir's video he points out how listening for extended periods and then switching makes discerning objective differences impossible.

So, I will be very interested to hear what you determine when you can blind test. Getting the levels matched is critical. That said, because we cannot overcome our cognitive bias, if you are like me using a DAC I have sitting around does subjectively sound better, even if it isn't.

bokolobs....Question: Darko's review of the NAD C 338 says it has Chromecast Audio built in...why not use that instead of the CCA?

 

[TonyB]

This is an interesting discussion on DACs and their influence on sound. I've seen many DAC reviews and all of them refer to the influence that the DAC has on the sound quality and character, even so far as saying that ladder R2R DACs sound more analogue than delta sigma. Are we saying that it's all nonsense and these reviewers are deluded?

The corollary is that so called audiophile equipment costing thousands is really just an indulgence in cognitive bias. Is that true?

 

[Julf]

This is an interesting discussion on DACs and their influence on sound. I've seen many DAC reviews and all of them refer to the influence that the DAC has on the sound quality and character, even so far as saying that ladder R2R DACs sound more analogue than delta sigma.

Yes, there are lots of claims out there.

Are we saying that it's all nonsense and these reviewers are deluded?

Not deluded, but driven by subjective beliefs and commercial motivations.

The corollary is that so called audiophile equipment costing thousands is really just an indulgence in cognitive bias. Is that true?

Mostly yes.

 

[BDWoody]

Are we saying that it's all nonsense and these reviewers are deluded?

The corollary is that so called audiophile equipment costing thousands is really just an indulgence in cognitive bias. Is that true?

Roughly speaking, pretty much.

There are lots of valid reasons to pay more for nice things, but when they are sold based on some kind of sound quality improvement, that's going to be an issue.

 

[Jimbob54]

This is an interesting discussion on DACs and their influence on sound. I've seen many DAC reviews and all of them refer to the influence that the DAC has on the sound quality and character, even so far as saying that ladder R2R DACs sound more analogue than delta sigma. Are we saying that it's all nonsense and these reviewers are deluded?

The corollary is that so called audiophile equipment costing thousands is really just an indulgence in cognitive bias. Is that true?

Its Sunday afternoon so it must be time for another "all DACs sound the same"- "Oh no they dont! " debate.

Lets put it a better way. Your DAC should be the last place you look to change or indeed improve your audio. A DAC with good measurements should be audibly transparent. Anything that isnt is either coloured intentionally, or by poor design.

Similar can be said for solid state amps as long as they have adequate power to handle whatever transducers you have and measure well, what scope is there for them to be more than transparent? If they have a sound, thats distortion of some kind or another.

Do they all sound the same? No. But if I am spending mega $$$ on something, should I not aim for for something that doesnt colour my signal, looks nice and functions well. I can add any amount of EQ , distortion etc to my hearts desire in software.

Put a blindfold on, match the output levels and lots of the magic from the $$$ melts away. Whats left is colouration.

EDIT- I think this is where a lot of the conflict / debate arises. The "trust your ears" line of thinking is right, to a degree. If you like how something sounds, and it gives you pleasure, great. But the reality (argue the more objectively minded folks) is that a lot of the qualities you think you like dont actually exist. So you are paying for an expensive magic trick/ wilful deception. Or you are paying for colouration. And there are far more cost effective ways to get that.

 

[DSJR]

High dynamic range has nothing to do with dynamic range but with output level. So avoid it unless your preamp can handle a 2V input. 2V into a sensitive preamp will produce clipping on input. Until quite recently I used the analogue output into an old Quad 33 preamp (and Quad electrostats, so a very resolving system). I then replaced the Quad 33 with an RME ADI-2 DAC/preamp for this and other digital sources, and there does seem to be a slight improvement. Whether that is the superior DAC in the RME or the superior quality of the RME unit as a preamp is unclear, but I think the new system just shows off that the late 1960's Quad 33 was an outdated piece of gear. So my conclusion is that maybe, just maybe, a good external DAC is better than the inbuilt DAC of the CCA, but only just, and only in a very good system. Similarly, I tried to compare all the various DACs that I have, and it was very hard to hear any differences between the decent ones. I could not really tell.

Willem, the 33 has quite definite high pass filtering below 35Hz or so and I gather it was to protect the 57 speakers with a 303 power amp that goes kind of wild into that load below 20Hz or so, which they can't reproduce anyway (I cite a HiFi News measurement article as evidence). The Dada updates to the 33 do help a bit, but the RMI will be in a different plane of existence so fair do's, but I'm not at all surprised you can hear a difference as even I can with my own 33.

 

[nerone]

Before the Topping E30 I owned the D30, even the latter sounded better than the CCA, I had to replace it because I burned it by mistakenly connecting it to a 28v power supply.
For a short time I used CCA in analog, well the difference for me is not a placebo effect as with E30 I hear more detail than CCA, it's like taking off a VELO (not a blanket) in front of the speakers.

 

[GGroch]

.......even so far as saying that ladder R2R DACs sound more analogue than delta sigma...

The R2R vs Delta Sigma pitch is a perfect example of how cognitive bias works. It is easy to draw out why R2R provides a more perfect waveform than delta sigma. In the Mid-80s I would draw the graphs on a pad a dozen times a week to upsell customers from a lower margin Sony to a more profitable 18-bit Onkyo DX7500. I was doing customer's a favor, it did sound better to me, and almost no customers returned them, we all could easily hear the difference (no one blind tested.) The problem is....when dealing with audio frequencies reality is nothing at all like the graphs, its just not true.

Whether you are considering DACs, cables, amps, or even things where there are real differences like headphones and speakers, the story is everything.

ADD: Daniel Kahneman discusses the importance of stories to belief in this speech. The link is to the last couple of minutes, but the whole thing is worth watching. The speech was given in 2012 but if you watch it from the start you'd swear it was written for 2020.

 

[Julf]

For a short time I used CCA in analog, well the difference for me is not a placebo effect as with E30 I hear more detail than CCA, it's like taking off a VELO (not a blanket) in front of the speakers.

Your subjective, unverified and unconfirmed perception is noted.

 

[nerone]

it is not as you say, in my system even a cable placed on the ground or placed on a soft cloth there is a clear difference and I do not use an expensive system.
Right now I wouldn't use CCA anymore without a good external dac.

 

[Julf]

it is not as you say, in my system even a cable placed on the ground or placed on a soft cloth there is a clear difference and I do not use an expensive system.

Sure. If you think so. I suggest you re-read the name of this forum (unless you are trolling on purpose).

 

[Jimbob54]

it is not as you say, in my system even a cable placed on the ground or placed on a soft cloth there is a clear difference and I do not use an expensive system.
Right now I wouldn't use CCA anymore without a good external dac.

*drum roll* Uh-huh

 

[nerone]

if I bought the D30 and the E30 it is thanks to having read and had advice on this site then ...
The differences in sound I hear are like having acoustic traps in the listening room, I have no instruments to measure but I tell you that without these the difference is considerable.

Greetings

 

[Julf]

I tell you that without these the difference is considerable.

Yes, you have made it clear that you believe so.

 

[bokolobs]

You're welcome! I am glad you found testing fun. Let me answer your questions the best I am able.

1. RE: Other DACs measuring better...2. Other DACs should not sound better in a blind listening test. Amir's recent very long video on Listening tests is excellent on this point. He describes an online A/B/X test posted by Archimago to see if anyone could hear the difference between 16 bit (96dB max S/N) and 24 bit (theoretically over 120 dB)...3. But, we will absolutely hear the difference in sighted tests. There is no way to overcome cognitive bias. The differences we hear can be huge as nerone noticed above. Being an experienced audiophile, having a highly resolving system and even exceptional ears makes absolutely no difference. Cognitive bias overwhelms everything else, it is how our brains work. In Amir's video he points out how listening for extended periods and then switching makes discerning objective differences impossible... So, I will be very interested to hear what you determine when you can blind test. Getting the levels matched is critical.... bokolobs....Question: Darko's review of the NAD C 338 says it has Chromecast Audio built in...why not use that instead of the CCA?

Many thanks! This was very informative. I'll check out the video later.

Yes, the C 338 has Chromecast Audio built in. I'm using one of my CCAs (analog output) as a streamer with an old (90s) amplifier set up in our living room and was just wondering if I could improve the sound by adding a Modi 2 Uber. I did the test using the NAD because it has a remote where I can switch inputs very quickly.

 

[aleksa.angelov]

I started a nice discussion here, few more pages were added to the thread and yet I'm not sure whether to proceed with the purchase of the E30 or not.

 

[Jimbob54]

I started a nice discussion here, few more pages were added to the thread and yet I'm not sure whether to proceed with the purchase of the E30 or not.

Here is an idea. Order the e30 from somewhere with a no quibble returns policy and test it against the CCA as the dac vs optical into the e30. Just make sure you match the levels. If you can't tell, return the e30, no harm, no foul.

 

[nerone]

I started a nice discussion here, few more pages were added to the thread and yet I'm not sure whether to proceed with the purchase of the E30 or not.

don't worry, if you buy it it will stay in your system forever

 

[aleksa.angelov]

@nerone @Jimbob54 Where I come from, It's very complicated to get something and then return it. I'll probably get it from the local dealer in the upcoming weeks. thank you very much for your comments.