yashsingh1/xdaforums huggingface dataset:
[Google Pixel 2 XL Guides, News, & Discussion] bjrmd:
According to this site the output of the Hifiman is 127 dB per volt. In comparison, my Se 846 would be 133 dB per volt (potentially dangerous).

For each drop of 6 dB, the voltage is half. So at .25 volts(half x 2) the drop is 12 dB giving you 115 dB which should blow out your ears.

The impedance is 34 Ohms, so yes you will only get the low voltage.

I get .9 V with my Senn 800s.

With a line out, you should get the full 1.8V (your car unit).

If you are using Neutron, did you normalize the tracks. Depending on the headroom chosen, that will also cut the gain quite a bit (I normalize at 16 dB down).
[Google Pixel 2 XL Guides, News, & Discussion] BaronInkjet:
Thanks for the info. That is a great site, had not seen it before. Those #s sound about right.

I have all the normalization features turned off. The biggest problem is some tracks are much lower than others. The Hifimans w/iphone can definitely inflict pain on some songs, but others I can listen at full volume and would like a little more. Adding bass (which they need) sucks a lot of power also.

I'm thinking the best step might be to try the HTC or Razer dongle, without the stages. Also in the hopper, I have an A&K 810 BT receiver due later this week. I got it for car, but will be interesting to see how it compares with these. Some say they think it is better than any phone output, but I am a little skeptical. But we shall see.

Again, thank you for all your efforts to sort all this stuff out!
[Google Pixel 2 XL Guides, News, & Discussion] bjrmd:
A couple of more thoughts:

Have you tried Gmusic tracks, but not your ripped songs(which may be recorded at a lower gain? They should play at full potential volume. For testing volume out, I would not use the Neutron driver as the android volume sometimes is low and hard to adjust depending on your settings(at least for me). I still think there is something fishy in the low output you are getting.

The HTC is a fine unit and the higher impedance should not be an issue for you. I am using that with my Senn800s.

Of course there is the Dragonfly red with 2.1 V, but cost is 20x the Google dongle.

I am personally not keen on bluetooth unless you are not interested in sound quality(even with better codecs, you are introducing transcoding and bit rate reduction).
[Google Pixel 2 XL Guides, News, & Discussion] BaronInkjet:
I agree on BT, am very skeptical. We're stuck without many options for a car though -- due to the charging issue. I don't want to have a big dongle and two cables flopping around in the car. And extension USB C cables are not spec. So only choices I see are ....

-- BT aptx HD

-- Chromecast Audio (Google doesn't support this and not sure this still works)

-- Use dongle or real DAC with cord, and turn off music when you need to charge phone.

Not great choices. (This is one instance where wireless charging would make a big difference.) There is a bunch of hardware that should exist but doesn't. For instance, there should be a Spotify Connect receiver. Once lossless Spotify comes online (in testing now) this would solve a lot of issues.

But I bought the BT receiver from a place with great return policy. I figure odds are 50-50 I will return it.

I'm going to continue to play with this dongle thing. It's mainly for the gym. Don't want to drag a separate real DAC around working out.

The Razer one will be interesting. GSMarena said it was loud, and I expect the Neutron tricks to work about the same.

We will see. I'll post back if I find anything of interest.
[Google Pixel 2 XL Guides, News, & Discussion] jasenko:
A bit off-topic but seems like even Qualcomm believe "dongle" business is going to explode and they want a piece of it.

http://www.androidpolice.com/2017/1...phone-dongles-sound-better-giving-hi-fi-dacs/
[Google Pixel 2 XL Guides, News, & Discussion] BaronInkjet:
Sign me up! :good:

I got my Astell & Kern BT device in the mail today. Oh my gawd!!!!! :victory: While it is not "quite" as pure as a cord, the overall presentation is head and shoulders above any smartphone I have ever heard. (Have not heard the new LGs though.) Such an expansive experience -- I see now why people complained that they could not use it as a USB DAC. I have used a few aptX BT devices over the years, and there is just no comparison. It is real now. I bought it for car, but may end up using it other places too.

On the dongle front, Amazon US has the Razers in stock again. So you can buy them without Razer's absurd shipping fees. I ordered one. In one of the phone reviews, it was measured and just over 1 volt. (VS. 0.9 for the A&K.) We will see.
[Google Pixel 2 XL Guides, News, & Discussion] reshas:
Could someone who has the app confirm that this works predictably? I know this may not last forever, but I'm preferring this for now in comparison to rooting (Control app) and the Bubble upnp workaround (which is very cumbersome).

BTW, any more dongles (how about the Razer one mentioned recently) giving better/clean output?
[Google Pixel 2 XL Guides, News, & Discussion] BaronInkjet:
The easiest way I have found is the Neutron option I described earlier. It works consistently with Spotify and with Tidal and sounds very good. I played around with UAPP but could not get it to work in similar fashion. Music would play from phone speakers instead of out via USB when the app is running. Though there is a native way to play Tidal using UAPP.

A couple of us have Razer's on order, but have not heard any first hand reports.

The problem I have had (and I think a lot of people will have) is the output level for the Google dongle. At typical IEM resistance, it outputs about 1/3 of iphone -- even though it is capable of much more. It's a shame because it is beautifully clean using the Neutron trick. The reason I ordered a Razer is one of the reviews measured it at over 1 volt.
[Google Pixel 2 XL Guides, News, & Discussion] reshas:
thanks.. are you talking about the below snippet?

--

Question about Neutron if anyone knows...

I have not yet used Neutron on my Pixel, but it keeps asking me if I want Neutron to be default USB software when I plug in adapter to port. Question: Might Neutron's USB out system affect any of the Google Dongle issues?

p.s. I am still remembering how Neutron works, but by disabling generic driver it does seem to give a lot better quality than anything I have tried so far (Neutron with default settings/Spotify/Tidal). Also of note, there is a setting in Neutron to use slider to control hardware (DAC) level.

--

has this been tested on pixel 2? would I be able to use it predictably to play from google music? appreciate any help in confirming as well as high level instructions (since I have never used Neutron so far).

thanks once again and waiting to have a workable solution.. i'm pretty unhappy in the audio department after switching to pixel 2 (and using the stock dongle).
[Google Pixel 2 XL Guides, News, & Discussion] BaronInkjet:
Read the last two weeks of posts.
[Google Pixel 2 XL Guides, News, & Discussion] bjrmd:
I have made a tutorial on how to use the Neutron driver

https://xdaforums.com/pixel-2-xl/how-to/usb-c-dac-gain-control-root-tutorial-t3715278
[Google Pixel 2 XL Guides, News, & Discussion] rockingondrums:
Great thread. I've seen your other thread with the app.

I primarily use USB audio out with Android Auto on my 1st generation Pioneer AVIC 8000 series head unit. I believe it was the first head unit ever released with Android Auto.

As I'm already connecting directly to my HU USB port, there's no dongle DAC in the chain. So then I must be relying solely on the phone hw / sw.

I imagine I should still see a benefit?

My next roadblock is that I don't have a pair of headphones to plug in to my dongle to activate the app. Also, I wouldn't need to calibrate it to headphones, just to the direct USB connection to my HU. Is that how I should set it up, while directly attached to my HU? Thanks!
[Google Pixel 2 XL Guides, News, & Discussion] bjrmd:
The benefit of keeping the USB Dac digital gain down is highest at the lower range of power output(sensitive IEM). So since you are probably wanting higher Dac voltage in your car setup, I would just keep the stock implementation. Also, given the car and road noise, I doubt you would hear the difference in sound quality.
[Google Pixel 2 XL Guides, News, & Discussion] bjrmd:
Review of Razer Usb Dac

I had high hopes for this but testing was very disappointing.

Impedance 5 Ohms

Crosstalk loaded 50 dB (unloaded 60 dB)

Max power .85 V

Distortion tracings:

At full volume:

Listening volume with stock (full digital gain) driver settings:

Optimized gain settings (reduce digital Dac gain, max android volume of 25):

Distortion even present at very low Dac gain:

Comparison to the Google Dac at this test series (not historical data)

Summary

Razer Dac is much larger in size and weight.

Impedance relatively high.

Crosstalk very good

Output average for class (about 1 V)

Distortion bands even at optimized Dac digital gain and low outputs--worst in my testing so far.

Going back to Amazon!
[Google Pixel 2 XL Guides, News, & Discussion] BaronInkjet:
[MENTION=298372]bjm[/MENTION]rd,

Did you listen to the Razer? How did it sound?
[Google Pixel 2 XL Guides, News, & Discussion] bjrmd:
I did not spend much time listening yet.

Just wanted to get out some objective measurements.

In general, I'm not one to find great utility in subjective impressions. We all hear things a bit differently, and even a couple of dB can make the gear seem better.
[Google Pixel 2 XL Guides, News, & Discussion] samteeee:
Thank you for your time, great stuff.

I was wondering if you'd suggest an app

to control the digital gain, I have root.

Thank you.
[Google Pixel 2 XL Guides, News, & Discussion] bjrmd:
This is my app

What Usb Dac are you going to use?
[Google Pixel 2 XL Guides, News, & Discussion] samteeee:
Great, thanks bro.

I'm just gonna stick with Google's for now.

And also got a bluetooth one with Qualcomm support.

I have a Google music sub or I would've used the Noutron driver.
[Google Pixel 2 XL Guides, News, & Discussion] bjrmd:
The 9$ Google dongle is superb.

My app, Google music and the Google Dac are a perfect combo.

You probably couldn't tell the difference with a Dragonfly.
[Google Pixel 2 XL Guides, News, & Discussion] jasenko:
Please don't tell me that... I am trying so hard not to root the phone, and you are not helping. Apart from Android Pay, would I lose much other functionality if I root the Pixel?
[Google Pixel 2 XL Guides, News, & Discussion] samteeee:
From reading your threads I kinda thought that is the case

but Thank you for confirming that.
[Google Pixel 2 XL Guides, News, & Discussion] bjrmd:
Ha, sorry to tempt you.

I don't know what else you could lose.

It wasn't hard but if you didn't already unlock the bootloader, doing so will wipe your phone and you then need to set it up again.

Come to think of it, I did not double check to see if the gain problem was corrected in 8.1.

Let me take a quick look and report back on that
[Google Pixel 2 XL Guides, News, & Discussion] BaronInkjet:
My Razer is due in tomorrow (Wed). So far, the A&K device is far ahead of Google one w/Neutron (or of iphone 6, for that matter.) It's like adding a DAC vs underpowered phone output in both cases. And the iphone has a little more power than A&K.

I still want to spend some time with the "lack of punch" issue with Google dongle. But so far the three-tier output scheme seems the likely culprit. Razer will help to sort that perhaps also.

Thanks again for all your work here!!!!
[Google Pixel 2 XL Guides, News, & Discussion] jasenko:
Kind of doubt they did anything. I think it even sounds slightly worse than before (or maybe my ears have grown accustomed to Dragonfly a bit too much).
[Google Pixel 2 XL Guides, News, & Discussion] BaronInkjet:
You can see it sounds like just by using the Neutron USB driver with Neutron, Spotify, Tidal... no root required.

What headphones do you use? The big gotcha is the three tier output from the Google dongle. Most high quality IEMs only get .37 volts due to their impedance, which is a little more than a third of iphone. And it is not enough for most people.
[Google Pixel 2 XL Guides, News, & Discussion] jasenko:
I tried this combo and it only sounds good if I go through Neutron/BubbleUPNP (Google Play Music), the driver won't work with other apps once it's made exclusive to Neutron.

And yes, I use Shure SE425s
[Google Pixel 2 XL Guides, News, & Discussion] BaronInkjet:
I can use it all day long with both Spotify and Tidal. Stop, restart, whatever and never mess with Neutron except when plugging in USB. I was not able to make it work with Google Music though; they may check to see if Android USB driver is in place in startup.
[Google Pixel 2 XL Guides, News, & Discussion] bjrmd:
If anything the distortion banding is worse.

Stock:

But with gain optimization:
[Google Pixel 2 XL Guides, News, & Discussion] bjrmd:
As far as the voltage limitation of the Google Dac, I think this is misinterpreted.

For high sensitivity iem, let's say the se425, the max dB at 350 mV or so is still 115 which will cause permanent hearing damage.

If you're using over the ear cans, you get .9V, with the Sennheiser s I have, that's over 100 dB.

Although the OSHA limits are 85 dB, studies show that people using personal music players at volumes above 80 dB are more likely to get permanent damage.

I have a 20 dB noise induced cut in my left ear in the 3 to 7 khz range just from a large fan that was on that side of my body. I would use the fan to cool off after biking and even checked the dB with an SPL meter which showed 75 dB. According to my Ent, the published limits are way off.

Just be careful, you would hate to damage your hearing just when you get to the point in your life that you can afford high end gear.
[Google Pixel 2 XL Guides, News, & Discussion] jasenko:
Thanks for doing the test... And glad you confirmed that my ears were not playing tricks on me. Oh well, don't think they would fix this before the next major update (very low priority for majority of people). Time to do something about it myself. :crying:
[Google Pixel 2 XL Guides, News, & Discussion] BaronInkjet:
I got my Razer -- it doesn't work. I tried both on phone and my XPS 15 and nada, so I'm thinking I got a bad one. Google dongle works on both.
[Google Pixel 2 XL Guides, News, & Discussion] jawmail:
I got one and it worked fine same with the HTC and google adapters. The Razor really snapped in the port with a pronounced click, it required a bit more force than the others. So make sure it's in all the way:)
[Google Pixel 2 XL Guides, News, & Discussion] BaronInkjet:
Yes, it is definitely a snug fit. I pushed as hard as I dared, took off case, etc. Not a hint of recognition with phone or computer. I think I'll get refund for now and get HTC.
[Google Pixel 2 XL Guides, News, & Discussion] bjrmd:
The Razer Dac uses impedance sensing to "announce" it's presence to the Pixel. You may want to try another headphone, the 3.5mm socket may be a bit temperamental. If the jack connection is not solid, the Dac is basically inert.

The Google Dac behaves this way but the Realtec, Dragonfly do not.
[Google Pixel 2 XL Guides, News, & Discussion] BaronInkjet:
Best I was able to get was to get same dialogue in phone as plugging in to computer -- supplying power, do you want to transfer files, pics, etc. Tried different headphones, car aux... does not matter.

---------- Post added at 06:58 PM ---------- Previous post was at 06:19 PM ----------

Restarted the phone and finally got it to connect. To me is obviously less good that Google one, sans the output level. Higher output is better for my IEMs on the Razer though. The sound though is like the Google one using the stock Android USB driver -- just not clean. Cymbals are particularly rough after hearing Google w/Neutron or A&K. I don't know if my Neutron trick might not work with Razer, or if it's just the higher distortion as noted by [MENTION=281070]bjrmd[/MENTION]. In any event, I'm not keeping them.

[MENTION=281070]bjrmd[/MENTION], the power issue is not about loudness. Half the IEM reviews you read on HeadFi talk about how phones open up and sound different with an external DAC vs phone, etc. I'm not sure if "clipping" is exactly the term, but something like that.
[Google Pixel 2 XL Guides, News, & Discussion] bjrmd:
Sure, if the Dac voltage max is substantially less, the distortion could be much higher since the system is at near peak.

But, with most mobile setups that use sensitive IEMs, the above senario doesn't occur.

You could get an idea for the output you need. If you listen to your tracks at full scale let me know the Android volume setting, the model of headphone, and we can figure it out.
[Google Pixel 2 XL Guides, News, & Discussion] bjrmd:
Made a simple spreadsheet with data so far:

The above numbers are using my gain control app, android volume at 25/25 to produce the best possible output signal

Note, the voltage at distortion threshold is the point where harmonic banding becomes >5 dB.

The THD is the harmonic distortion at 250 mV, this would be about 90 dB using full size cans like the Senn 650/800 that have a sensitivity of 103 dB/V.

Will work on uploading the exact images if anyone is interested.
[Google Pixel 2 XL Guides, News, & Discussion] BaronInkjet:
Ultrasone

This is a little different animal from $9 dongles -- more in line with Dragonfly Red -- but some might be interested. What is neat about (besides specs) is that it has direct cables for USB C, lightning, etc.

https://www.moon-audio.com/ultrasone-naos-hi-res-dac-for-smartphones.html

I was able to get some real specs on it also:
[Google Pixel 2 XL Guides, News, & Discussion] Burninh2o:
Between Google stock and the Realtek dongles, which one do you recommend the most with the UAC app on a rooted Pixel 2?

Also, would Viper4Andoid and UAC interfere with each other?

Thanks for the reviews. Cheers!
[Google Pixel 2 XL Guides, News, & Discussion] bjrmd:
The Google Dac is a custom Realtec variation.

It is capable of 3x the voltage, is smaller, cheaper, and has the lowest distortion if driven properly.

So that would be my choice without doubt as long as you use my app or something like that.

But for the un rooted devices, the Realtec I tested is perhaps a better choice since it exhibited less distortion at the default gain settings.

The generic Realtec would have several dB less headroom driving low efficiency headphones.

The chart above is a good guide for what each Dac is capable of doing at it's best using proper settings.

To my knowledge, Viper should not have an issue with this.
[Google Pixel 2 XL Guides, News, & Discussion] pixelsquish:
I read most of the thread and I find the HTC dongle to be noticeably better than the Google dongle. Not by a ton but easy enough to notice though. It's fuller and richer with better bass. The Google dongle sounds thin in comparison.

The razer dongle is on the way to try.

This was with A/B'ing the same tracks played via Google Play music and that's it. Using some very good IEM's, the Dunu DK-3001's.
[Google Pixel 2 XL Guides, News, & Discussion] Burninh2o:
Thank you. You just saved me some money. :)

Edit: Form the above post, what do you think about the HTC compared to Google (I can't really interpret the your chart, thus asking)?
[Google Pixel 2 XL Guides, News, & Discussion] bjrmd:
If you are running non rooted stock, the major difference would be higher impedance of the HTC, which may alter the frequency response of your headphones. This is the problem with my Shure se846, but wouldn't be for many others. So when you hear subjective impressions from users it can simply relate to this (hence why I avoid giving subjective opinions). Both Dac units will put out comparable power with high impedance full size headphones.

Both have excellent crosstalk.

If you're rooted and able to optimize gain settings, distortion is very close. The HTC does get to a slightly higher voltage before distortion becomes electrically noticable, but I don't think anyone would ever notice it by listening. They both are 24 bit capable.

Finally, the Google Dac is smaller, lighter than anything I have tested.

I bought the HTC dongle for testing, but plan to use it on my Senn800s since impedance wouldn't matter.

Lastly, for people who don't have root or don't want to bother with gain control, the generic Realtec would be my choice, the stock settings are better and impedance very low.
[Google Pixel 2 XL Guides, News, & Discussion] BaronInkjet:
That fits my experience with Google perfectly. With "low" resistance IEMs (which includes 90+% of "audiophile" ones), Google only gives you .37 v, which is about 1/3 of iPhone. And it is not enough to drive bass (which takes more power) so everything sounds flat.

I used Google in the car this weekend, plugged in to aux, and it is a completely different animal than with IEMs. Was listening to Spotify and Tidal using the Neutron driver and it sounds really, really nice. I wish it wasn't white, but otherwise am thinking it's going to live in the car.

I listened a little to the Razer, and it has plenty of power but is not as clean as Google. Have not tried HTC, but it seems like the best balance from what I read. (I'm mostly using A&K bluetooth, which sounds better than all of them -- though more expensive.)

It's just a shame Google went for this goofball three-tier power arrangement -- and without understanding the marketplace. The DAC volume stuff can be fixed, but this was just a blunder.
[Google Pixel 2 XL Guides, News, & Discussion] pixelsquish:
Whatever they did it's just average at best. I will get the Razer dongle and try it out and A/B it to both the google dongle and the HTC dongle. The 'measurements' in this thread stated that the Google dongle was better than the HTC one (and Razer one) but my ears say those objective measurements are missing something, and that is SQ. The HTC dongle almost, not totally but almost, made me not miss my LG V20. THe Google Dongle makes me miss my LG V20 audio output.

Whichever dongle wins I'll buy a few of - well at least until the next even better one comes out lol
[Google Pixel 2 XL Guides, News, & Discussion] BaronInkjet:
Without addressing the driver issue in one of the various ways, I'm guessing they are all going to sound pretty average.
[Google Pixel 2 XL Guides, News, & Discussion] mlavende:
Sennheiser PXC 550 headphones

Not sure if it's relevant, but I'm lucky enough to own a pair of these Sennheiser PXC 550s and as well as using BT I can also plug them into the Pixel2 via the USB C socket and they sound wonderful. No adapter beyond a straight USB A to C cable. They use the sennheiser DAC.

Just mentioning it in case anyone else has similar headphones and they haven't thought to try them

-Mat
[Google Pixel 2 XL Guides, News, & Discussion] pixelsquish:
turns out the Razer Dongle ships from Hong Kong. So it takes a minute to get here. Picked up by carrier on the 16th in HK and got to Fed-Ex's hub in Tennessee today. Now it's gotta make it to Jersey - hoping with Saturday delivery. Can't wait to test it out!
[Google Pixel 2 XL Guides, News, & Discussion] pixelsquish:
Razer Dongle arrived. The cable part of the dongle is 3x longer than that of the htc & google dongle.

SQ was immediately apparent as better than the google dongle. What was also immediately apparent was that the audio would cut in and out of the right channel when I moved about. So this puppy is defective. I don't have much time to A/B this with the HTC dongle since I'm shipping my Pixel 2 XL out for an RMA, but I did a little bit. Sound from the Razer seems to be nice and full but also with great clarity - more so than the HTC dongle. Just a little bit clearer but noticeable.

I'd go Razer>HTC in a close race with Google decently behind.
[Google Pixel 2 XL Guides, News, & Discussion] ismailonrails:
Does Razor Audio Adapter works with Pixel 2 XL?

Will Razor Audio adapter works with Google Pixel 2? and will it be better than stock Audio Adapter? Should I buy Razor adapter?