Does a dongle sound the same, regardless of device?

January 28, 2023 2:15 PM

I don’t fully understand the dongles you can get that aim to improve audio quality. Roughly speaking, their internal components hijack the components of the device they are plugged into. But does this mean that – if using the same headphones – they will sound the same whatever you plug them into?

So for example, a cheaply made phone versus a high end one, or an old laptop versus something that cost a fortune…if you use the same headphones and listened to the same audio (say, a YouTube video) would the sound be identical, somewhat similar, or completely different?

Easy explanations or personal experiences very much appreciated!

posted by Calvin and the Duplicators to Technology (16 answers total)

Best answer: If you're talking about DACs, then that's a lot of the idea; given the same USB-based input on one end, they *should* be producing the same analog output.
posted by sagc at 2:29 PM on January 28, 2023

Best answer: (but I'm not sure what you mean about hijacking internal components, so you might be talking about something wildly different.)
posted by sagc at 2:30 PM on January 28, 2023

Response by poster: Well, I was referring to products like the Dragonfly series or Apple's headphone jack adapter. Thanks so much for the replies so far!
posted by Calvin and the Duplicators at 2:47 PM on January 28, 2023

Best answer: The digital-analog converter can only base its output on the quality of audio file input that it has to work with. So, if the hardware on the dongle is better than the hardware your output normally uses, then yes it could conceivably produce better output. Not sure if the average person would be able to tell the difference without special tools.
posted by erpava at 3:11 PM on January 28, 2023

Best answer: There are ways for the device to mess with the dongle (e.g. not powering it at the proper voltage or powering it at an inconsistent voltage), but if the device isn't doing anything like that, the sound should be pretty much identical.
posted by panic at 3:15 PM on January 28, 2023 [2 favorites]

Best answer: The DragonFly is a USB DAC. Whether or not it sounds better than a device's onboard DAC when playing back the source file depends on their respective hardware, the software support for each in the device, and your ears.
posted by snuffleupagus at 3:16 PM on January 28, 2023 [1 favorite]

Best answer: DACs like the ones you mention work by taking the digital stream from the USB (or Lightning, as the case may be) connector and converting it to analog audio.

Presuming the source material is the same, and that the phone/laptop/whatever is capable of providing a stream of bits and the required power for the DAC to work, the sound should be if not identical than very very similar.

(I have a Dragonfly, and to my ears it sounds better than any of the iPhones I've plugged it into. Not surprisingly, the difference is most noticeable with nicer headphones and higher-bitrate source material.)
posted by box at 3:30 PM on January 28, 2023 [2 favorites]

Best answer: If there are differences between the sound quality of a USB-connected DAC and the one built into the phone or laptop or whatever, those are most likely due to differences in the analog electronics that handle the signal after it's been converted. In particular, external DACs often sound better than a phone or laptop's inbuilt audio circuitry if for no other reason than being physically further away from sources of electrical noise like RAM chips and CPUs.
posted by flabdablet at 3:56 PM on January 28, 2023 [1 favorite]

Best answer: There is a lot of woo around DACs, and you get the same around cables, power supplies, and so on.

If your onboard audio is working correctly and doesn't have any obvious problems (ground loop hum, crackling, distortion), a DAC is going to sound the same when you plug your headphones in. People will argue about this all day but there are a lot of people who have done a lot of measurements and the results are the same.

If a DAC has features your onboard audio doesn't, and you need those features, that's a great reason to get a DAC. Arguably the only reason to get a DAC for almost anyone. But it will sound the same, assuming everything is working properly. Maybe a lot louder. But same quality.
posted by Jairus at 4:04 PM on January 28, 2023 [3 favorites]

Best answer: If your onboard audio is working correctly and doesn't have any obvious problems (ground loop hum, crackling, distortion), a DAC is going to sound the same

Whether or not I agree with that depends on whether "working correctly" means "working well" or "working as designed".

I've heard all of those obvious problems, along with obvious power supply rail borne noise, in lots of inbuilt device headphone circuitry and had markedly better results from external DACs. I've also had much worse sound (assorted kinds of noise, dreadful frequency response) out of cheap no-brand USB audio adapters than the inbuilt circuitry was capable of before its 3.5mm socket broke.

Commodity jellybean digital circuitry is all much of a muchness these days but there are real and obvious differences in the quality of analog electronics, especially at low price points. Some is really good value and some is utter crap. Luck of the draw, really.
posted by flabdablet at 4:47 PM on January 28, 2023 [2 favorites]

Best answer: Audio Science Review tests audio devices of various kinds, relying on measuring them instead of just listening to them and trying to describe what they hear.

Here's their review of the Apple headphone jack dongle. "I can recommend the Apple USB-C headphone adapter. For many people it may replace the portable thumb drive dac+amps."

And here's their review of the $300 AudioQuest Dragonfly Cobalt dongle. "While with high impedance headphones, the AudioQuest Dragonfly Cobalt has acceptable subjective performance, it fails in so many other ways that I cannot recommend it."

For comparison, here's their review of the $900 SMSL SU-10, a bigger, powered, box of a DAC, which I think has the highest rating from their reviews. "The SU-10 is an excellently engineered DAC. It aims to squeeze the last bit of performance available. Such improvement is limited by how well I can measure it due to analyzer noise itself. We clearly have state of the art performance here. Whether that justifies the higher cost is something that is your business and not mine."

In my uneducated opinion, judging by reviews like this, these devices do have measurably different outputs, and presumably are different again to the onboard DACs in laptops, phones, etc. But whether your ears and brain can actually discern these differences is another matter.
posted by fabius at 1:07 AM on January 29, 2023 [1 favorite]

Best answer: Presuming the source material is the same, and that the phone/laptop/whatever is capable of providing a stream of bits and the required power for the DAC to work, the sound should be if not identical than very very similar.


To clarify, I'm talking here about using the same DAC with different devices. Different DACs sound different. My Dragonfly Red sounds better to me than my Dragonfly Black (though it also uses a lot more of my phone's battery).

As others have said, whether you can hear these differences is a different question.
posted by box at 6:42 AM on January 29, 2023

Best answer: FWIW, I have an aging TEAC HA-P50 that I take on trips, only. Because in addition to being a DAC it is has more output power to drive random devices I might be able to plug into, plus it functions as a battery.

Unless you have audiophile headphones that *need* a DAC (you'd already know), it's unlikely you'll hear a noticeable difference versus the output of recent smartphones (via a dongle or on andriod phones that still have miniplugs) unless you need more output power.

Specs-wise, in 2021 the Apple dongle was able to do 44.1 or 48 kHz, at 16 or 24 bitrate w/a max output 1 Vrms.
posted by snuffleupagus at 2:29 PM on January 29, 2023

Best answer: While digital signal is a digital signal, no matter how you transmit it, how the digital signal is converted to an analog signal for your ears *can* make a difference, and that's the domain of the DAC - digital-analog converter.

To simplify things, when regular analog music is converted to digital format, a frequency (sampling rate) is chosen, and then, every cycle in that simpling rate, a certain number of bits are used to represent that moment in time. For Example, CD-quality music is sampled at 44100 Hz or 44.1 Khz, at a 16-bit resolution. So every second, the sampler records 44100 16-bit numbers per channel (double that for stereo).

You can overdo it, like 192 Khz sampling, at 24-bit resolution, for example. Generally, if you do better than CD-quality, that's considered "hi-res" music.

Your computer, your phone, Bluetooth headsets, etc all have DACs, but they generally are NOT built for high-precision high-res audio. A good DAC needs to support the highest rates available and works backward from there. It also needs clean signals, a mostly neutral digital amp, and good timing circuitry to reduce jitter (clock error causing slight timing issues on playback).

And MP3 is NOT a good source of audio, due to compression, among other things. Same with streaming, unless they promise high-res audio (Tidal, etc.) Basically, nothing will make garbage audio sound good.

So to answer your original question

Q) if using the same headphones – they will sound the same whatever you plug them into? (DAC vs no DAC)

A) It depends on the source material. If the source material is hi-res audio, then you may hear a difference. If it's just random Youtube or Free Spotify, then "no, you won't hear a difference", since low-quality sources equal low-quality outputs.

However, if you have high-res digital music, such as those streamed by Tidal MQA format, or Apple's hi-res ALAC format, or even the free format FLAC, then using a DAC will make a difference, esp. a DAC that is better than the built-in DAC.

Also keep in mind that most cheaper headphones do NOT need an amp, but those that do, will benefit a lot from it. And a lot of the "portable" DACs are actually DAC-Amp combos. And if you have a headphone that needs an amp to get the most out of it, then having one will make a difference as well.
posted by kschang at 10:29 PM on January 29, 2023 [1 favorite]

Best answer: You can overdo it, like 192 Khz sampling, at 24-bit resolution, for example. Generally, if you do better than CD-quality, that's considered "hi-res" music.

The only real use for 192kHz sampling and 24-bit or higher resolution is as an intermediate format for audio effects processing and mixing in the digital domain during the record production process. Actually distributing finished mixdowns encoded at higher sampling rates than 48kHz, or higher resolutions than 16 bits per sample, is a pointless waste of space and bandwidth that can never sound better and might sound worse; "better than CD quality" isn't actually a thing. Doesn't stop marketing departments from persuading people it is, though, on the obvious basis that mo numbers equals mo better.

All the highest notes, neither sharp nor flat.
The ear can't hear as high as that!
Still, I ought to please any passing bat
With my high fidelity!

16 bits per sample per channel times 2 channels times 44100 samples per second comes to 1.4Mb/s (i.e. 176 kbytes/s, or 635 megabytes per hour) so there's never a good reason to seek out a fatter bitstream than that for stereo audio. If what you actually care about is listening to recordings that sound exactly the way the recording engineer intended them to, 16 bit 44.1kHz CD quality is more than sufficient and by a comfortable margin at that.

FLAC or ALAC storage compression can cut the storage requirement for CD-quality audio to about a third of that, typically coming in at around 500kb/s or 200 megabytes per hour, by eliminating redundancy that's inherent in the fact that music is not random noise. The decoding process for a FLAC or ALAC stream re-inserts all of that redundancy, feeding the DAC with exactly the same bitstream as the pre-compression originals.

Music in any of these formats will almost always sound noticeably cleaner than MP3 audio compressed to 128kb/s or lower; MP3 and later compressors like AAC and Vorbis and Opus are lossy formats, and the lower the bit rate of the compressed result, the more quality is lost. Even so, it's a rare recording that reveals any audible difference between an uncompressed original and an MP3 encoded at 192kb/s or more, or an AAC or Opus encoded at 160kb/s or more.

I have never once encountered a 320kb/s MP3 that's audibly different from its CD-quality source, even when listening on high end equipment. Even so, I keep my own music library, most of which was ripped from CDs, in FLAC format so that I can rule out even the theoretical possibility of quality loss.

There exist cheap-ass no-brand USB DAC dongles that mess up their analog side badly enough that it becomes hard for even practiced ears to tell the difference between a 128kb/s MP3 source and the same thing straight from CD when played through them. Most USB DACs are nowhere near that bad, though, and most phone-sourced listening is done in relatively noisy environments where you'd be hard pressed to pick the difference between what comes out of an external DAC and what your phone can do natively. And there's way more quality variation across different models of headphones and earbuds than there is across not-obviously-shit DAC dongles.
posted by flabdablet at 6:41 AM on January 30, 2023

Response by poster: Thanks, everyone! I got a lot out of this, and really appreciate all the comments.
posted by Calvin and the Duplicators at 5:20 PM on February 5, 2023