Gunter
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Please improve the sound quality of the Raspberry Pi product.

Sun Jul 05, 2020 8:20 am

Dear Sir or Madam.

Will it please be possible to forward this message to the correct person or department?

I would like to ask your company a question about the Raspberry Pi product.

According to a video on the web site of Youtube, the audio quality of the product of your company isn’t very great. For example: if you connect a headphone to the audio jack on the Raspberry Pi product, the audio a person can hear from the headphones isn’t CD quality and a person can hear a lot of noise due to interference caused by some components on the Raspberry Pi product. Here is the video: https://www.youtube.com/watch?v=cjqEPyMr1zI

There are many people who attempted to develop a music player software program (like Windows Media Player) and install it on the Raspberry Pi and then discovered that the audio quality of the Raspberry Pi isn’t very good.

I will appreciate it if your company can develop a product with better sound quality. I can then use the product of your company in industrial applications. For example: the Raspberry Pi can be used in radio applications.

Is there anybody who agrees with me? Must the company, Raspberry Pi, improve the sound quality of their product? What do you think?

What can be used to improve the sound quality of the Raspberry Pi product and where can a person buy the product?

Thank you.
Regards.
Jean de Klerk.
Last edited by Gunter on Sun Jul 05, 2020 9:19 am, edited 3 times in total.

LTolledo
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Re: Please improve the sound quality of the Raspberry Pi product.

Sun Jul 05, 2020 8:28 am

to get the best audio experience with the RPi
one needs to invest on I2S DAC.

there are so many in the market.
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jdb
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Re: Please improve the sound quality of the Raspberry Pi product.

Sun Jul 05, 2020 8:34 am

"Hey, a random youtuber claims your product has poor feature X, please fix" - the video itself offers no supporting evidence or even measurement of the supposed quality. What's a "polluted USB bus", anyway?
Rockets are loud.
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Re: Please improve the sound quality of the Raspberry Pi product.

Sun Jul 05, 2020 8:36 am

The Pi is a extremely cost optimised product. Adding a significantly better analogue audio output would increase the cost for everyone and only be used by a small proportion of users.
As mentioned there are plenty of add on boards to provide higher quality analogue audio or if you really want an on board solution, and are prepared for the cost and minimum order quantities, a customised version service is available.
https://www.element14.com/community/doc ... on-service

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PeterO
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Re: Please improve the sound quality of the Raspberry Pi product.

Sun Jul 05, 2020 8:36 am

Gunter wrote:
Sun Jul 05, 2020 8:20 am
Dear Sir or Madam.

Will it please be possible to forward this message to the correct person or department?

I would like to ask your company a question about the Raspberry Pi product.

According to a video on the web site of Youtube, the audio quality of the product of your company isn’t very great. For example: if you connect a headphone to the audio jack on the Raspberry Pi product, the audio a person can hear from the headphones isn’t CD quality and a person can hear a lot of noise due to interference caused by some components on the Raspberry Pi product. Here is the video: https://www.youtube.com/watch?v=cjqEPyMr1zI

There are many people who attempted to develop a music player software program (like Windows Media Player) and install it on the Raspberry Pi and then discovered that the audio quality of the Raspberry Pi isn’t very good.

I will appreciate it if your company can develop a product with better sound quality. I can then use the product of your company in industrial applications. For example: the Raspberry Pi can be used in radio applications.

Thank you.
Regards.
Jean de Klerk.
HiFI audio is not needed for the main use cases of the PI so it's unlikely to happen, plus "feature request" threads normally get locked on here....
Plus you already know the solution, it is shown in the video you linked to :roll:

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fruitoftheloom
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Re: Please improve the sound quality of the Raspberry Pi product.

Sun Jul 05, 2020 8:56 am

Gunter wrote:
Sun Jul 05, 2020 8:20 am
Dear Sir or Madam.

Will it please be possible to forward this message to the correct person or department?

I would like to ask your company a question about the Raspberry Pi product.

According to a video on the web site of Youtube, the audio quality of the product of your company isn’t very great. For example: if you connect a headphone to the audio jack on the Raspberry Pi product, the audio a person can hear from the headphones isn’t CD quality and a person can hear a lot of noise due to interference caused by some components on the Raspberry Pi product. Here is the video: https://www.youtube.com/watch?v=cjqEPyMr1zI

There are many people who attempted to develop a music player software program (like Windows Media Player) and install it on the Raspberry Pi and then discovered that the audio quality of the Raspberry Pi isn’t very good.

I will appreciate it if your company can develop a product with better sound quality. I can then use the product of your company in industrial applications. For example: the Raspberry Pi can be used in radio applications.

Thank you.
Regards.
Jean de Klerk.

HDMi Audio is perfectly acceptable for a SBC at this price point, try it sometime soon :?
Thinking outside the box is better than burying your head in the sand...

jamesh
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Re: Please improve the sound quality of the Raspberry Pi product.

Sun Jul 05, 2020 9:39 am

Gunter wrote:
Sun Jul 05, 2020 8:20 am
Dear Sir or Madam.

Will it please be possible to forward this message to the correct person or department?

I would like to ask your company a question about the Raspberry Pi product.

According to a video on the web site of Youtube, the audio quality of the product of your company isn’t very great. For example: if you connect a headphone to the audio jack on the Raspberry Pi product, the audio a person can hear from the headphones isn’t CD quality and a person can hear a lot of noise due to interference caused by some components on the Raspberry Pi product. Here is the video: https://www.youtube.com/watch?v=cjqEPyMr1zI

There are many people who attempted to develop a music player software program (like Windows Media Player) and install it on the Raspberry Pi and then discovered that the audio quality of the Raspberry Pi isn’t very good.

I will appreciate it if your company can develop a product with better sound quality. I can then use the product of your company in industrial applications. For example: the Raspberry Pi can be used in radio applications.

Is there anybody who agrees with me? Must the company, Raspberry Pi, improve the sound quality of their product? What do you think?

What can be used to improve the sound quality of the Raspberry Pi product and where can a person buy the product?

Thank you.
Regards.
Jean de Klerk.
These guys make good add on boards. No point in building that sort of feature set in, most people won't use it. So best done with an add on board.

https://www.hifiberry.com/
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TimG
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Re: Please improve the sound quality of the Raspberry Pi product.

Sun Jul 05, 2020 11:51 am

LTolledo wrote:
Sun Jul 05, 2020 8:28 am
to get the best audio experience with the RPi
one needs to invest on I2S DAC.

there are so many in the market.
Pimoroni used to make a very good audio DAC for UKP 7.50, but it seems to have been discontinued.
The nearest equivalent I can find is from Adafruit: https://www.adafruit.com/product/4037
There's also a similar non-hat version (needs a bit of wiring, but may fit into cases which don't otherwise accept hat boards): https://www.adafruit.com/product/3678

jamesh
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Re: Please improve the sound quality of the Raspberry Pi product.

Sun Jul 05, 2020 12:28 pm

The OP has edited the first post, not sure what changed. I've locked it so it cannot be edited again. Please make any changes in the thread itself.

If the OP want to use the pi in industry, and needs high quality audio, the suggestions above will work - just add an appropriately specc'd audio HAT. Its industrial, so the cost is going to be fairly immaterial.

Or alternatively, design a CM carrier board with inbuilt audio. Again, appropriate for industrial use.

We are not planning on improving the analogue audio (the digital audio is already high quality, or you can use Bluetooth for high quality headphones), it's added cost for everyone even though only a few people use it.
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JumpZero
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Re: Please improve the sound quality of the Raspberry Pi product.

Sun Jul 05, 2020 1:07 pm

To me the analog audio jack is perfect
Specialy since 2017 and firmware improvement (sigma-delta noise shaping): viewtopic.php?f=29&t=195178
I have a Raspberry Pi Model B Rev 2 (that's a Pi 1) as a web radio connected to an AKAI HiFI 2x40W amplifier and speakers, it's just perfect
No noise even if I push the volume to the max. The pi is powered with a good official Raspberry pi power supply.

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rpdom
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Re: Please improve the sound quality of the Raspberry Pi product.

Sun Jul 05, 2020 1:14 pm

jamesh wrote:
Sun Jul 05, 2020 12:28 pm
The OP has edited the first post, not sure what changed.
According to the google cached version of the page, these last two lines were added.
Is there anybody who agrees with me? Must the company, Raspberry Pi, improve the sound quality of their product? What do you think?

What can be used to improve the sound quality of the Raspberry Pi product and where can a person buy the product?
Unreadable squiggle

fruitoftheloom
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Re: Please improve the sound quality of the Raspberry Pi product.

Sun Jul 05, 2020 1:25 pm

Gunter wrote:
Sun Jul 05, 2020 8:20 am
Dear Sir or Madam.

Will it please be possible to forward this message to the correct person or department?

I would like to ask your company a question about the Raspberry Pi product.

According to a video on the web site of Youtube, the audio quality of the product of your company isn’t very great. For example: if you connect a headphone to the audio jack on the Raspberry Pi product, the audio a person can hear from the headphones isn’t CD quality and a person can hear a lot of noise due to interference caused by some components on the Raspberry Pi product. Here is the video: https://www.youtube.com/watch?v=cjqEPyMr1zI

There are many people who attempted to develop a music player software program (like Windows Media Player) and install it on the Raspberry Pi and then discovered that the audio quality of the Raspberry Pi isn’t very good.

I will appreciate it if your company can develop a product with better sound quality. I can then use the product of your company in industrial applications. For example: the Raspberry Pi can be used in radio applications.

Is there anybody who agrees with me? Must the company, Raspberry Pi, improve the sound quality of their product? What do you think?

What can be used to improve the sound quality of the Raspberry Pi product and where can a person buy the product?

Thank you.
Regards.
Jean de Klerk.

Thank you for changing your post, unfortunately the information you added is incorrect, there is no company called Raspberry Pi.

As a first time poster you should of researched this subject before posting and not rely on some half-baked YouTube Video.

As clearly stated above and in previous posts regards any feature request, it has likely been already considered in the past 9 years.


If you are developing a product then you should use the Compute Module, as already stated, as that will give you flexibility to add the features you desire on your baseboard design:

The WaveShare CM development board may be a good starting point for designing your own baseboard:

https://www.waveshare.com/wiki/Compute_ ... Board_Plus
Thinking outside the box is better than burying your head in the sand...

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Re: Please improve the sound quality of the Raspberry Pi product.

Sun Jul 05, 2020 2:44 pm

I feel a need to give input.
just because a friend has been building one.

and to give a place to buy some of the good linked above.

https://thepihut.com/collections/hifiberry

A nice selection, and cable connections.

It really is great how you can add things to these Pi.

Just like I can add quality cards to PCs, I do miss the days of AWE32/64 Gold and better cards I could just slot in, before all this PCI mess ;-).

drgeoff
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Re: Please improve the sound quality of the Raspberry Pi product.

Sun Jul 05, 2020 3:48 pm

At 3:31 in that YouTube video the speaker says

"In general the RaspberryPi 4B sounds somewhat less open, has slightly less sibilance control while the stereo image was narrower".

I smell BS. The only way a RPi4B and a 3B+ can be different in those aspects if the digits they are feeding to the DAC are not the same. That would mean that the same audio player running on the two machines is producing different output bit streams from the same audio source input. Granted that induced noise and interference into the analogue circuits of the DAC might be different between a 4B and 3B+ but no way is that going to affect the width of the stereo image.
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Re: Please improve the sound quality of the Raspberry Pi product.

Sun Jul 05, 2020 5:39 pm

Sorry, the credibility of the video also goes down when he starts suggesting that you separate your audio devices from other devices on the network by plugging in a separate network switch. You'd really have to be going some for that to make a difference, as most network switches have backplane switching capabilities that are significantly greater than any real world use case. Take a cheap 8 port switch such as the Netgear GS108, and it has 10Gbit/s of switching capacity - that's all 8 ports saturated at 1000baseT.

And a minor correction - the 3B+ has gigabit ethernet, although over USB2.

There is science behind audio engineering, but at audiophile level there is also a lot of snake oil.

As others have said, the analogue output is never going to be pristine. Use an external DAC if you really care.
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epoch1970
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Re: Please improve the sound quality of the Raspberry Pi product.

Sun Jul 05, 2020 6:18 pm

Gunter wrote:
Sun Jul 05, 2020 8:20 am
Is there anybody who agrees with me? Must the company, Raspberry Pi, improve the sound quality of their product? What do you think?
I have built various instances of Pi3B with either analog audio or the Justboom AMP, with a 24V PSU. A couple of years ago, that was "the" big gun. Using a specialized OS, piCorePlayer. Stereo application.
This is what I think:
- There is 0 practical difference in AQ in a regular environment between the built-in and the ludicrous DAC included w/ the JustBoom AMP
- The i2s interface becomes a problem as soon as you need source mixing. In the built-in device, the mixer is included. No fiddling with alsa, no issues with frequency and sample size.

To summerize: a) the built-in device is very good, b) it is easy to use. I don't see there is anything to improve, at least in stereo mode.
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Re: Please improve the sound quality of the Raspberry Pi product.

Sun Jul 05, 2020 6:41 pm

This is 'audiophile' bul^Wnonsense. These are the credulous idiots who pay $1k/metre for one-way ethernet cables. And no, I'm not joking.

'Byebee Quantum Purifiers' are my personal favourites, in this space. But I did recently see a 6-way US power strip for (IIRC) the bargain price of $4800, which comes close.

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Re: Please improve the sound quality of the Raspberry Pi product.

Sun Jul 05, 2020 7:11 pm

epoch1970 wrote:
Sun Jul 05, 2020 6:18 pm

To summerize: a) the built-in device is very good, b) it is easy to use. I don't see there is anything to improve, at least in stereo mode.
There are a few things about the PWM DAC that suck, and unfortunately are impossible to fix without re-implementing silicon and spending more money on the output drive.

- High output impedance
The output is RC filtered which means you have an AC output impedance equivalent to the parallel resistance of the two resistors in the filter circuit. In practice this means you have 50-75 ohms in the audio band which means a suboptimal impedance match when driving low-impedance headphones. 32 ohm headphones are generally fine, but anything lower than that and you will have significant attenuation.

- Full-scale output is -10dBV
The single-ended line driver is powered from 3v3 (or 2v5, depending on model) and goes through a resistive divider resulting in a 1.25V pk-pk AC output (=> 0.44V RMS). This is a bit less than standard line level.

- PWM generator is trailing-edge
See: https://en.wikipedia.org/wiki/Pulse-width_modulation fig. 5
Trailing-edge modulation introduces 2nd order distortion of the baseband signal because the PWM pulses have a phase shift that is proportional to PWM duty cycle. The distortion is proportional to the amplitude of the signal and the ratio of PWM carrier frequency to baseband frequency, so high output levels at high frequencies mean higher harmonic distortion. At max output and 1kHz, the THD is 0.1%. The fix for this is for the SoC to have a generator that does dual-edge modulation, so the center of the modulator pulse always coincides with a fixed periodic interval.

- Poor bass response into low-impedance loads
The output DC blocking capacitors are 47uF which form a high-pass filter when coupled with a low-impedance load. For a typical 32 ohm headphone driver, the -3dB roll-off is ~100Hz which is a little too high for perfect reproduction. Things are made worse with the MLCC dielectric of the output capacitors having a large voltage-dependent electrical permittivity, so you get more bass distortion with lower-impedance loads.

The actual digital output has a 92dB SQNR, though.

TL;DR is that the onboard analogue audio works fine as a line-level driver, lacks in more demanding applications.
Rockets are loud.
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Aire
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Re: Please improve the sound quality of the Raspberry Pi product.

Sun Jul 05, 2020 7:13 pm

Despite what Douglas Adams suggested I think the OP really needs a sense of perspective.
A board that costs as little as the 4B isn't in HiFi territory. Nor should it be.
My HiFi amp cost 12 times a much as the 8Gb version, but its not much good at connecting to the internet, running office, streaming Netflix or any of the multitude of other things that the Pi is great at.
I mean - seriously, is it the first of April?
P1 3B+; 4B 4Gb/SD; 4B 8Gb with 240Gb SSD booting off SD
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LTolledo
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Re: Please improve the sound quality of the Raspberry Pi product.

Sun Jul 05, 2020 7:39 pm

so in the end its

1. bear with provided analog/HDMI (not audiophile quality but works just fine)
2. install an audio DAC
3. nothing follows....

the OP has not returned to contribute.....

lets call it a day.... ;)
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Come to me with 'problems' and I'll help you find solutions"

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Heater
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Re: Please improve the sound quality of the Raspberry Pi product.

Sun Jul 05, 2020 8:41 pm

Gunter wrote:
Sun Jul 05, 2020 8:20 am
I will appreciate it if your company can develop a product with better sound quality. I can then use the product of your company in industrial applications.
Let me get this straight, a charitable organization with a mission in education should build a product, for a dirt cheap price, so that you can profit from it in some "industrial applications"?

I think not.

Of course it's great when a Pi is useful in such roles but really, don't expect them to go out of their way to help your business.

I have never used any audio features of a Pi. If it sounded as good as a 1960's six transistor radio I would be happy for the price. I'm sure it is way better than that.
Memory in C++ is a leaky abstraction .

hippy
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Re: Please improve the sound quality of the Raspberry Pi product.

Sun Jul 05, 2020 11:05 pm

JumpZero wrote:
Sun Jul 05, 2020 1:07 pm
To me the analog audio jack is perfect
I certainly haven't had any cause for complaint except the output voltage level could be higher than it is, and that could be more an amplifier input issue.

It has been fine for me running through my Hi-Fi Amp and speakers, sound-wise it is comparable to what I hear from my CD player as far as my ears are concerned.

That is with a 3B (non-plus). Haven't tried a 4B.

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Re: Please improve the sound quality of the Raspberry Pi product.

Mon Jul 06, 2020 3:22 am

Sound is perfect with my Logitech Z130 speakers, if you want to use headphones you'd need a headphone amplifier.

pagenotfound
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Re: Please improve the sound quality of the Raspberry Pi product.

Thu Jul 30, 2020 5:42 pm

jdb wrote:
Sun Jul 05, 2020 7:11 pm
epoch1970 wrote:
Sun Jul 05, 2020 6:18 pm

To summerize: a) the built-in device is very good, b) it is easy to use. I don't see there is anything to improve, at least in stereo mode.
There are a few things about the PWM DAC that suck, and unfortunately are impossible to fix without re-implementing silicon and spending more money on the output drive.

- High output impedance
The output is RC filtered which means you have an AC output impedance equivalent to the parallel resistance of the two resistors in the filter circuit. In practice this means you have 50-75 ohms in the audio band which means a suboptimal impedance match when driving low-impedance headphones. 32 ohm headphones are generally fine, but anything lower than that and you will have significant attenuation.

- Full-scale output is -10dBV
The single-ended line driver is powered from 3v3 (or 2v5, depending on model) and goes through a resistive divider resulting in a 1.25V pk-pk AC output (=> 0.44V RMS). This is a bit less than standard line level.

- PWM generator is trailing-edge
See: https://en.wikipedia.org/wiki/Pulse-width_modulation fig. 5
Trailing-edge modulation introduces 2nd order distortion of the baseband signal because the PWM pulses have a phase shift that is proportional to PWM duty cycle. The distortion is proportional to the amplitude of the signal and the ratio of PWM carrier frequency to baseband frequency, so high output levels at high frequencies mean higher harmonic distortion. At max output and 1kHz, the THD is 0.1%. The fix for this is for the SoC to have a generator that does dual-edge modulation, so the center of the modulator pulse always coincides with a fixed periodic interval.

- Poor bass response into low-impedance loads
The output DC blocking capacitors are 47uF which form a high-pass filter when coupled with a low-impedance load. For a typical 32 ohm headphone driver, the -3dB roll-off is ~100Hz which is a little too high for perfect reproduction. Things are made worse with the MLCC dielectric of the output capacitors having a large voltage-dependent electrical permittivity, so you get more bass distortion with lower-impedance loads.

The actual digital output has a 92dB SQNR, though.

TL;DR is that the onboard analogue audio works fine as a line-level driver, lacks in more demanding applications.
A belated Thank You for this informative and honest post. Very interesting as I'm currently planning to buy new headphones. Apart from the standard advice to use 32 ohm headphones little is known about this matter. The official docs do not even state the usual output impedance at 1 khz (or maybe I don't know the location of the real docs). It seems though that the 69 ohm someone calculated after looking at the schematics are roughly correct.

While I'm at it: if you are the person who wrote the new output driver, thanks again. It made a real difference for me.

jamesh
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Re: Please improve the sound quality of the Raspberry Pi product.

Thu Jul 30, 2020 9:03 pm

pagenotfound wrote:
Thu Jul 30, 2020 5:42 pm
jdb wrote:
Sun Jul 05, 2020 7:11 pm
epoch1970 wrote:
Sun Jul 05, 2020 6:18 pm

To summerize: a) the built-in device is very good, b) it is easy to use. I don't see there is anything to improve, at least in stereo mode.
There are a few things about the PWM DAC that suck, and unfortunately are impossible to fix without re-implementing silicon and spending more money on the output drive.

- High output impedance
The output is RC filtered which means you have an AC output impedance equivalent to the parallel resistance of the two resistors in the filter circuit. In practice this means you have 50-75 ohms in the audio band which means a suboptimal impedance match when driving low-impedance headphones. 32 ohm headphones are generally fine, but anything lower than that and you will have significant attenuation.

- Full-scale output is -10dBV
The single-ended line driver is powered from 3v3 (or 2v5, depending on model) and goes through a resistive divider resulting in a 1.25V pk-pk AC output (=> 0.44V RMS). This is a bit less than standard line level.

- PWM generator is trailing-edge
See: https://en.wikipedia.org/wiki/Pulse-width_modulation fig. 5
Trailing-edge modulation introduces 2nd order distortion of the baseband signal because the PWM pulses have a phase shift that is proportional to PWM duty cycle. The distortion is proportional to the amplitude of the signal and the ratio of PWM carrier frequency to baseband frequency, so high output levels at high frequencies mean higher harmonic distortion. At max output and 1kHz, the THD is 0.1%. The fix for this is for the SoC to have a generator that does dual-edge modulation, so the center of the modulator pulse always coincides with a fixed periodic interval.

- Poor bass response into low-impedance loads
The output DC blocking capacitors are 47uF which form a high-pass filter when coupled with a low-impedance load. For a typical 32 ohm headphone driver, the -3dB roll-off is ~100Hz which is a little too high for perfect reproduction. Things are made worse with the MLCC dielectric of the output capacitors having a large voltage-dependent electrical permittivity, so you get more bass distortion with lower-impedance loads.

The actual digital output has a 92dB SQNR, though.

TL;DR is that the onboard analogue audio works fine as a line-level driver, lacks in more demanding applications.
A belated Thank You for this informative and honest post. Very interesting as I'm currently planning to buy new headphones. Apart from the standard advice to use 32 ohm headphones little is known about this matter. The official docs do not even state the usual output impedance at 1 khz (or maybe I don't know the location of the real docs). It seems though that the 69 ohm someone calculated after looking at the schematics are roughly correct.

While I'm at it: if you are the person who wrote the new output driver, thanks again. It made a real difference for me.
Yes, he is.
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Contrary to popular belief, humorous signatures are allowed.
I've been saying "Mucho" to my Spanish friend a lot more lately. It means a lot to him.

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