Dongle sound quality.

[modifier]

I think some are going to the extreme. The choice is simple.

We get your point but the choice isn't that simple for everyone. Have you tried driving sensitive IEMs or high-impedance headphones? Sensitive IEMs will hiss in the background and high-impedance headphones need amplification. The adapter is fine for most people and most situations but not all people and all situations. The discussion about DAC/amps has been intertwined with the adapter discussion and perhaps those details were lost in the noise.

The adapter is good though. Most here will agree. I believe we established that a couple pages ago.

 

[Almeuit]

We get your point but the choice isn't that simple for everyone. Have you tried driving sensitive IEMs or high-impedance headphones? Sensitive IEMs will hiss in the background and high-impedance headphones need amplification. The adapter is fine for most people and most situations, but not all people and all situations.

Then I would suggest they find a phone that does work for them if they truly need a dedicated headphone jack .

 

[modifier]

Then I would suggest they find a phone that does work for them if they truly need a dedicated headphone jack .

A dedicated headphone jack isn't the issue. This isn't "yet another 3.5mm jack is gone" topic. In the situation I'm discussing with @Mike Dee and @e30ernest, we're talking about portable DAC/amps to drive headphones in a way that no phone can, not even the V30 depending on the headphone.

 

[Almeuit]

A dedicated headphone jack isn't the issue. This isn't "yet another 3.5mm jack is gone" topic. In the situation I'm discussing with @Mike Dee and @e30ernest, we're talking about portable DAC/amps to drive headphones in a way that no phone can, not even the V30 depending on the headphone.

Ah okay. I just tossed it to another headphone jack thread since 99% of the time it is that. My bad ^_^.

 

[modifier]

Ah okay. I just tossed it to another headphone jack thread since 99% of the time it is that. My bad ^_^.

Unfortunately many are seeing it that way. LOL

There are two discussions going on here; one about whether or not the adapter sounds better than the stock SoC DAC (which it does) and one about using a small, portable USB DAC/amp to exceed what the adapter can do. Since an adapter is needed, a small thumb-drive sized DAC/amp isn't much more hassle... sort of.

 

[LeoRex]

Since an adapter is needed, a small thumb-drive sized DAC/amp isn't much more hassle... sort of.

Well.. that also rolls in my point in a way. Amplifiers don't make the sound, they amplify it. And as the old saying goes, 'garbage in, garbage out'. Going to USB Audio doesn't just help the experience you get from run of the mill ear buds and headphones, it should also help if you are going to send the signal into some high end gear. Wouldn't you rather a 'pure' digital input rather than one that's already been screwed with by the phone's internal DAC and amp? As I've mentioned before, back when I was playing with high end car audio, one of the starting points was a head unit with an unamplified lineout, rather than fuss with the speaker outputs. This is effectively doing the same thing.

 

[modifier]

Well.. that also rolls in my point in a way. Amplifiers don't make the sound, they amplify it. And as the old saying goes, 'garbage in, garbage out'. Going to USB Audio doesn't just help the experience you get from run of the mill ear buds and headphones, it should also help if you are going to send the signal into some high end gear. Wouldn't you rather a 'pure' digital input rather than one that's already been screwed with by the phone's internal DAC and amp? As I've mentioned before, back when I was playing with high end car audio, one of the starting points was a head unit with an unamplified lineout, rather than fuss with the speaker outputs. This is effectively doing the same thing.

Not sure I follow. Every phone has a DAC of some type, whether it be on-die (built into the SoC), a discreet chipset (ie: LG V-series) or external (USB-C to 3.5mm adapter, built into USB-C headphones or in a USB DAC/amp combo). You can't turn digital sound into analog waveforms without a DAC. Even the original Motorola brick has a Ti DAC to convert voices, bleeps and bloops into sounds that we humans can hear. In the case of the Pixel 2, it has both an on-die and external DAC. The on-die drives the internal speakers and the external drives the USB adapter. There's no line-out from the SoC in this case since the software driver pushes all bits to the external DAC when connected and bypasses the SoC DAC.

USB headphones aren't purely digital. There's still an analog signal hitting the speakers. Going to USB audio for headphones only means the DAC is now on an external discreet chipset rather than internal/on-die. How 'pure' the signal is depends entirely on the circuitry. That typically requires a Class-A DAC/amp combo where the amp circuit is solid-state in the truest sense and has capacitors outside of the final audio path.

Now, if you're connecting an amp and not a DAC/amp to the USB-C to 3.5mm adapter, then yes, that's certainly possible. Whether or not it's better depends on many factors. It would sound better only if the adapter's DAC sounds better than the DAC it replaces.

The DAC inside the adapter is better than the SoC DAC but not better than many (but not all) DAC/amp combos. I tend to prefer the original Burr-Brown DACs (the design is now owned by Ti), some models of Wolfson DACs (now Cirrus Logic... as found in the Essential USB-C adapter and older BlackBerry devices) and I'm now warming up to the AK4490 found in many Schiit and CEntrance DACs. I also like tube amps with the right headphones but mostly use solid state. 'Better' is always relative, subjective and personal.

TL;DR:
For the Pixel 2 / 2 XL owner running MP3s or streaming music in lower than DSD quality and using standard headphones or earbuds, the dongle should be perfectly acceptable and sound great. For those wanting FLAC/WAV and DSD support with hard-to-drive IEMs or headphones, the dongle might not be the right answer.

Apologies for the long post.

 

[LeoRex]

In the case of the Pixel 2, it has both an on-die and external DAC. The on-die drives the internal speakers and the external drives the USB adapter. There's no line-out from the SoC in this case since the software driver pushes all bits to the external DAC when connected and bypasses the SoC DAC.

Just for clarification sake.. there is no analog conversion internal to the phone (ignoring the phone's speakers here).. the signal coming out of the USB port is purely digital. You need to plug something in that supports the USB digital audio spec, which is very new, in order to access it. That is why Google included a USB-DA adapter with the Pixels.

There may or may not be any external accessories out there that support USB-DA yet (haven't looked), but when there are, you can plug that directly into the phone without using the Google dongle and you'll be providing it a pure digital signal. So all the D/A conversion will occur inside that external device... It won't have to deal with an already converted analog signal, which probably isn't all that great.

If you are going to plug in a piece of expensive audio gear, wouldn't you want it to be fed the most unaltered signal possible?

 

[modifier]

Just for clarification sake.. there is no analog conversion internal to the phone (ignoring the phone's speakers here).. the signal coming out of the USB port is purely digital. You need to plug something in that supports the USB digital audio spec, which is very new, in order to access it. That is why Google included a USB-DA adapter with the Pixels.

Correct. I mentioned all of that above.

There may or may not be any external accessories out there that support USB-DA yet (haven't looked), but when there are, you can plug that directly into the phone without using the Google dongle and you'll be providing it a pure digital signal. So all the D/A conversion will occur inside that external device... It won't have to deal with an already converted analog signal, which probably isn't all that great.

Wouldn't all USB-C headphones fall into this category already? I mentioned USB headphones above as well.

If you are going to plug in a piece of expensive audio gear, wouldn't you want it to be fed the most unaltered signal possible?

Yes, but "the most unaltered signal" isn't the issue here. Plugging any piece of audio gear into the USB-C to 3.5mm adapter puts the user at the mercy of the DAC inside the adapter and without an amplifier, so the adapter would be a compromise in some cases. Some here might want either a better DAC or a better DAC with an amp. No one's arguing the quality of the adapter. It's a fine piece of equipment for what it is. But, it's also only $9 and has its limitations. lol

 

[LeoRex]

Yes, but "the most unaltered signal" isn't the issue here. Plugging any piece of audio gear into the USB-C to 3.5mm adapter puts the user at the mercy of the DAC inside the adapter and without an amplifier, so the adapter would be a compromise in some cases. Some here might want either a better DAC or a better DAC with an amp. No one's arguing the quality of the adapter. It's a fine piece of equipment for what it is. But, it's also only $9 and has its limitations. lol

The adapter does have an built-in amplifier. It gets power (and control) from the phone over USB. That was one of the big advantages going to the new spec.... Much more robust high speed data and power capabilities.

 

[modifier]

The adapter does have an built-in amplifier. It gets power (and control) from the phone over USB. That was one of the big advantages going to the new spec.... Much more robust high speed data and power capabilities.

Perhaps we're looking at amplification differently. 3.3V or 5V over USB doesn't carry enough wattage without capacitors, which the adapter doesn't have. The adapter alone can't drive my 110Ω, 300Ω, 470Ω and 600Ω headphones with any kind of power, even with the volume at 100%. Conversely, it can drive my 56Ω IEMs but not with the same punch as a proper amp.

Built-in power delivery over USB is nowhere near what a dedicated amp can provide.

Like I said, for most users the adapter is fine. It's good enough for me for travel use. But, there are definitely cases where it's simply not enough and doesn't carry an advantage.

 

[LeoRex]

Built-in power delivery over USB is nowhere near what a dedicated amp can provide.

Oh, of course.. it's capable of pushing enough juice to power plenty of buds and earphones , but won't drive the big stuff.

The biggest issue we have at the moment is the spec is barely a year from being published and the list of phones that support is pretty thin... And accessories follow users. So it's too everyone's benefit of we stop crying foul about jacks and start asking for USB DA gear.

Once the market has plenty of headphones capable of USB-C digital audio (powered via USB) and plenty of USB-C/DA external DAC/amplifiers... We should all be happy and all the 'no headphone jack' grumbling will be a thing if the past.

 

[modifier]

I agree with all of that. That's why this isn't yet another "my 3.5mm jack is missing" thread. It's entirely about how the dongle sounds. I don't think anyone in here has griped about the change. Thankfully that's been left for other threads.

 

[KrisYYC]

Has anybody noticed that battery drain while playing music via the dongle is a bit higher than playing music from a phone with a 3.5mm headphone jack? That seems to the case with me. Also the dongle gets a tad warm. I guess this is due to the dongle having a small DAC inside?

 

[Mike Dee]

Has anybody noticed that battery drain while playing music via the dongle is a bit higher than playing music from a phone with a 3.5mm headphone jack? That seems to the case with me. Also the dongle gets a tad warm. I guess this is due to the dongle having a small DAC inside?

To be honest haven't noticed.... Not saying it isn't true, just haven't noticed. It shouldn't be that significant a difference, however we are talking about comparing via two different phones so that might not be accurate.

 

[modifier]

Has anybody noticed that battery drain while playing music via the dongle is a bit higher than playing music from a phone with a 3.5mm headphone jack? That seems to the case with me. Also the dongle gets a tad warm. I guess this is due to the dongle having a small DAC inside?

I've not personally tested this. Have you tested using the same phone, same app, same songs, same headphones and same volume level to make sure you're comparing 1:1? You'd need a phone with an internal 3.5mm jack and a USB-C port. It's certainly possible that the adapter uses slightly more power but "a bit" is difficult to define without controlled testing.

Keep us posted on your results. It would be interesting to know what you find. If you have access to a proper multimeter and a USB-C extension cable, you could measure actual power draw by the adapter.

 

[Mike Dee]

For the Pixel 2 / 2 XL owner running MP3s or streaming music in lower than DSD quality and using standard headphones or earbuds, the dongle should be perfectly acceptable and sound great. For those wanting FLAC/WAV and DSD support with hard-to-drive IEMs or headphones, the dongle might not be the right answer.

I find that FLAC files are noticeably better than non FLAC files on decent headphones... Not hard to drive of course.

 

[modifier]

I find that FLAC files are noticeably better than non FLAC files on decent headphones... Not hard to drive of course.

Yes, a library full of FLACs is great. That's one place where 128GB and no MicroSD slot can be limiting. I tend to either limit the number of songs on my phone or use high-quality MP3s for songs I don't listen to as often.

 

[Mike Dee]

Yes, a library full of FLACs is great. That's one place where 128GB and no MicroSD slot can be limiting. I tend to either limit the number of songs on my phone or use high-quality MP3s for songs I don't listen to as often.

I forgot to state through the supplied dongle but perhaps that was understood.

 

[modifier]

I forgot to state through the supplied dongle but perhaps that was understood.

Yup, I understood. What headphones are you using most often?