When it comes to DACs you want it to
-exhibit flat frequency response,
-have inaudible THD+N (below -80 dB)
-match its output voltage with the device you have it connected to (gain-stage)
When these criterias are met you'll soon find yourself looking only for features as all of them are audibly indistinguishable. To mention a few surprises;
-The Chromecast Audio
-The apple lightning to jack-out dongle (yes, it has in-built DAC)
-The Wiim series
All of these are transparent despite their vastly different designs and will not be worse or better sounding than the most expensive audiophile DAC you can find.
Contrary to what many will tell you, a quality DAC has no sound signature. It just converts the 1's and 0's into waveforms.
There is also no correlation between price and sound quality.
Don't worry about codecs. Any modern DAC will support the ones you mention. What you'll want to determine is how you will interact or connect with the DAC.
-WiFi streaming or
-LAN to access local files
-Bluetooth
-Airplay
I think these two articles will be great reads for you:
Well, do you? Chris explains what a DAC does, and what very specific circumstances you'd need to meet to benefit from one.
www.soundguys.com
Bit depth is all about noise, so how does more data affect the quality of your recording? Let SoundGuys explain.
www.soundguys.com
Thanks for both reads. They are very interesting, but they don't necessarily answer my question.
Let's take a real world example. My phone has a DAC and it supports the SBC, AAC, and LDAC codecs. My Bluetooth headphones have DACs and they support the SBC, AAC, and LDAC codecs. Whorah! They both support the same codecs so they can talk to each other.
There's a catch, however: they both default to the SBC codec, and I want to stream hi-res music from Qobuz. SBC and AAC don't support 24-bit/96-Khz streams, so I have to use the LDAC codec if I want to hear hi-res audio streams. So I enable this codec on my phone (and the headphones abopt it automatically) and bang! The quality of the music is greatly enhanced, at least on lots of classical, jazz, and electronic music streams. (I can't really hear a difference on most electric guitar-heavy recordings.)
Everything in the "Do You Need a DAC" article makes perfect sense from a high-level electronics point of view. A great source file should pass smoothly through the DAC and the analog signal should go happily out into the world. But if you look at the issue from a more detailed processing power standpoint, not all things are equal.
So heres my theory of why things are not equal: There is more overhead when processing data at a higher bit rate at a greater bit depth. Many more calculations have to be run, and to do that efficiently, you have to have fast flash memory to feed a cache that feeds the cpu running the codec that demands greater processing power to create wave forms as fast as it can to send a higher-quality analog signal out the door. (Get all of that? Your DAC has to.) All the data have to arrive in a coherent stream (point-to-point streaming) and so the load is uneven, I believe.
I don't know this for sure, but I'm betting processing MP3 signals using the SBC codec takes a lot less processing power than it takes to process 24‐bit/96-Khz signals using a more complex LDAC codec.
Here's how I came up with my crazy theory.
When I enabled the LDAC codec, my headphone started "distorting" frequencies and dropping the Bluetooth signal. Within the range of human hearing, bottom to top, I could find 12 frequencies that were being distorted. I checked using a frequency generator from the app store. The signal drops seemed random.
So I started to do research and discovered some interesting things associated with the LDAC codec. First is, the codec supports something called A2DP. A2DP allows the source streaming device (in this case, my Samsung S24 phone) to offload it's digital stream to the DAC in my headphones (in this case, my Sony 1000XM5s buds). As I described above, I suspect the buds' DACs don't have the horsepower to perform processing the hi-res stream.
So you can turn off A2DP offloading. This forces the source device to use its own DAC to decode the digital stream and then broadcast an analog signal to the headphones. Of course this signal is lossy, (I'll fight to the death over lossy signals not being all they're cracked up to be.), but the distortion was gone! My theory is, the phone's DAC has enough processing power to handle a 24-bit/96-Khz signal processed using the LDAC codec.
Who knew? My phone has more computing power than the 1st eighteen computers I owned.
So I go back to my questions, which could be summarized this way: while all DACs should process digital signals the same way, all DACs are not created equal to handle that processing, right?
And if that is true, while consumers may not know it, some DACs, based in their hardware configuration, can only support codecs like SBC and ACC, which are not capable of supporting he-res source signals.
And, thus, we have the Tidal Myth, which says, consumers can't hear a difference between Spotify and hi-res Tidel because their DAC (on their phone or computer or whatever) doesn't support LDAC or aptX HD for any number of reasons, or they think they can hear a difference because they just want to.
Of course the Tidal Myth doesn't actually exist if the listener uses a DAC that is properly configured both in terms of hardware and codecs.
Frankly, until I figured all this out, I couldn't hear a difference with Qobuz, except in my mind. I thought if the stream said it was 24‐bit/96 Khz, I must be hearing a difference. I'm still not sure that's not true, but I think it is. The question is, do you, or anyone, think it is.
