I found the perfect solution for dissipating the heat from the Pi 4 ! ! !
That should do it but it kind of ruins the form factor...
Only $20 and currently available for pre-order:
https://www.seeedstudio.com/ICE-Tower-CPU-Cooling-Fan-for-Raspberry-pi-Support-Pi-4-p-4097.html
An externally hosted image should be here but it was not working when we last tested it.
That should do it but it kind of ruins the form factor...
Only $20 and currently available for pre-order:
https://www.seeedstudio.com/ICE-Tower-CPU-Cooling-Fan-for-Raspberry-pi-Support-Pi-4-p-4097.html
A fan is never perfect
A fan is far from perfect... I prefer "fanless".
I would love to see a large passive heat sink, a properly designed one, and not one "borrowed" from a GPU that has the fins too closely spaced to work properly in free air without strong forces convection. I would love to see this fitted to the side of the Pi 4 that bears the SOC and other controller chips, with some heat transfer to each of them. Then I would like to see some kind of way to still allow HATs to be used - perhaps installing them somehow on the back side of the board, or at 90 degrees to the board? But all of these things cost money. The Pi and its support network are really top notch, but I can step up to an small Intel based miniPC and leave all of this in the rear view mirror.
Yes and no. You can get good and cheap intel-based hardware, but kernel-wise it's not always better/more consistent than rpi. The auxilliary stuff is less neat, no Hifiberry HATs (although there is now a little USB-HAT converter in beta-testing, allowing to use Hifiberry units as USB audio devices for non-rpi PCs). There are always trade-offs.
Personally, I have never had a rpi 3 overheat and throttle the cpu on playing music and running basic IIR dsp, so perhaps the rpi 4 won't either?
Also, I kind of wonder why people don't try out audio amplifier heatsinks. Designed for passive use, they make our DIY cases look like "real" audio devices etc.
There is a gent who posts some Pi cooling solutions he tests out on YouTube. IIRC the use of a PC heatsink with a copper pad in between to raise it high enough to clear the board, was very effective, even moreso with a fan. If the stock sized heatsink leaves one wanting, try the PC one with the copper pad... I'm tempted to try it one day, just gotta find a nice heatsink to use.
What I'm more curious about is whether I should let the Pi4 dictate my DAC purchase. I was hoping that using a USB DAC with the Pi4 would be better than with a 3, which I heard is not even really worth trying for hifi.
What I'm more curious about is whether I should let the Pi4 dictate my DAC purchase. I was hoping that using a USB DAC with the Pi4 would be better than with a 3, which I heard is not even really worth trying for hifi.
Running a PI as USB-DAC bridge is never been a good idea.
Perhaps it gets a little better with the Pi4.
To get around this weak spot Allo is working hard on a highest quality USB bridge based on the Pi compute module.
However. IMO the PI shines as I2S source. (with proper I2S DAC (re-)clocking scheme)
The top level HATs achieve outstanding jitter and noise levels. From that perspective there'd be no need for USB interfaces.
I'm more than happy getting rid of USB and all kind of USB filters altogether.
I run my 3B+ with Wifi and USB off (that alone saves 200mA =40%).
And if I need a serious computer - a workhorse - I take my NUC i5.
Enjoy.
Perhaps it gets a little better with the Pi4.
To get around this weak spot Allo is working hard on a highest quality USB bridge based on the Pi compute module.
However. IMO the PI shines as I2S source. (with proper I2S DAC (re-)clocking scheme)
The top level HATs achieve outstanding jitter and noise levels. From that perspective there'd be no need for USB interfaces.
I'm more than happy getting rid of USB and all kind of USB filters altogether.
I run my 3B+ with Wifi and USB off (that alone saves 200mA =40%).
And if I need a serious computer - a workhorse - I take my NUC i5.
Enjoy.
I finally got around to doing a proper (albeit somewhat rushed) A-B test between the RPi 3 and RPi 4 as audio streamers.
To keep the playing field as level as possible both of them were running the exact same software (Raspbian Buster Lite) with MPD loaded and were powered by the same (excellent) Salas L-Adapter PS.
Connection to my DAC (DIY dual AK4493, very detailed) was through USB.
The music streamed from a NAS box over Ethernet.
I had a friend over in order to at least try to have a bigger sample size (of ears).
The music used was a handful of tracks that we always use for such comparisons (well known material).
We listened using the RPi3, then shut it down and booted up the RPi4, listening to the same material.
Much to our surprise, we actually preferred the sound of the RPi3!
The RPi4's presentation had something of a "fatiguing" effect. The sound was a bit more "coarse" that that of the RPi3.
We are not talking about big differences here, but they were there.
So it seems like I'll be going ahead with my "Audio Pi" project after all (I was considering waiting for the Compute Module 4 to come out).
I'm really curious if anyone else has done such a comparison and come to a similar conclusion.
To keep the playing field as level as possible both of them were running the exact same software (Raspbian Buster Lite) with MPD loaded and were powered by the same (excellent) Salas L-Adapter PS.
Connection to my DAC (DIY dual AK4493, very detailed) was through USB.
The music streamed from a NAS box over Ethernet.
I had a friend over in order to at least try to have a bigger sample size (of ears).
The music used was a handful of tracks that we always use for such comparisons (well known material).
We listened using the RPi3, then shut it down and booted up the RPi4, listening to the same material.
Much to our surprise, we actually preferred the sound of the RPi3!
The RPi4's presentation had something of a "fatiguing" effect. The sound was a bit more "coarse" that that of the RPi3.
We are not talking about big differences here, but they were there.
So it seems like I'll be going ahead with my "Audio Pi" project after all (I was considering waiting for the Compute Module 4 to come out).
I'm really curious if anyone else has done such a comparison and come to a similar conclusion.
As written above it does not make much sense to use the crippled USB implementation of the Pi. Neither Pi3, nor Pi4 USB is useful if you want high quality audio output. Use the I2S output and if you want really high quality input for your DAC isolate and reclock the signal. USB is not a good way.
Did you use USB2 or USB3 on the RPi4?
USB 2.0. It's rumored that the USB interfaces found on many DACs don't really like USB 3.0 that much, but I don't have much first hand experience.
Though I did confirm that my XMOS-based implementation does work with the USB 3.0 ports of the RPi 4.
Last edited:
The USB implementation of the RPi 4 is in no way "crippled", and the USB implementations of the previous RPis even though limited were completely adequate for audio playback.
It is the RPi's I2S output that has always been sub-par, only supporting up to 192K PCM in most audio distributions, with a flawed clocking scheme and plenty of electrical noise. I haven't looked at the RPi 4's implementation but I suspect that it is pretty much the same as the previous implementations.
Besides, in order to use the I2S output you would need to either use LVDS converters (which do not help with the quality of the I2S signal) or put the RPi inside your DAC, a big no-no for me. Plus in any case you would need to do real reclocking with an FPGA.
A proper USB interface does away with all of these problems.
Are you in a position to repeat this test using an i2s output?
I have never quite understood the usefulness of a usb connection to the pi in a diy setup. With PCs there is just no choice, but why drag the usb complications where they only lead to unneeded overheads and additional noise?
He, he, i only saw you post above after posting. Seems we have diametrically opposed positions.
I find it useful to integrate the Pi into a dac and i use Ian's fifo in all my dacs apart from the DAM. USB cables sound so frighteningly different that this alone discourages me from using the interface in general.
Last edited:
@DimDim
You need get your head straight. Please stop spreading your
myths.
1. We achieve femtoseconds jitterlevel on the RPI with several I2S DACs.
Obviously that'll require a properly implemented HAT. Which are available!
I doubt any USB interface will do better on that account.
2. Noise
Again what matters is the attached HAT. Meanwhile noise levels
are achieved that scratch the measurement capabilities of HQ
measurement equipment.
There'd be 0 reason to switch to USB because of noise.
3. USB (interface) quality
No, it's not crippled. But it's a very basic implementation.
There are several HQ devices (USB bridges/gadgets) out there
proving that point. Even using USB from a NUC would have been
the better choice.
Until 3B+ the combined USB/networking on the PI was simply
unacceptable.
IMO USB is for those who want to keep their beloved USB DAC.
(I sold my USB stuff long ago... ...and never look back.)
4. I2S samplerate limitations
Just for you to know: 384k and 256DOP (But - you know that)
Not sure why you're talking about 192k!?!? Just to prove your point!
That's really cheap.
Enjoy.
You need get your head straight. Please stop spreading your
myths.
1. We achieve femtoseconds jitterlevel on the RPI with several I2S DACs.
Obviously that'll require a properly implemented HAT. Which are available!
I doubt any USB interface will do better on that account.
2. Noise
Again what matters is the attached HAT. Meanwhile noise levels
are achieved that scratch the measurement capabilities of HQ
measurement equipment.
There'd be 0 reason to switch to USB because of noise.
3. USB (interface) quality
No, it's not crippled. But it's a very basic implementation.
There are several HQ devices (USB bridges/gadgets) out there
proving that point. Even using USB from a NUC would have been
the better choice.
Until 3B+ the combined USB/networking on the PI was simply
unacceptable.
IMO USB is for those who want to keep their beloved USB DAC.
(I sold my USB stuff long ago... ...and never look back.)
4. I2S samplerate limitations
Just for you to know: 384k and 256DOP (But - you know that)
Not sure why you're talking about 192k!?!? Just to prove your point!
That's really cheap.
Enjoy.
I have done extensive tests on RPI4 USB 3 , RPI3 and our own solution
What we found , using AP analyzer is a change in THD+N. (at least 1db overall)
More significant , we found the harmonic pattern to be completely changed
3, 4(2db) , 5( 3db) , 7 , 9 , 11 , 13 , 15 , 17 and 20 harmonics increased around 9-10db (using RPI4 USB3 and very similar to USB2/rpi4)
Since the THD+N is mostly dominated by noise , overall number do not change much (as I said 1db)
However ,I am a"believer" that harmonic pattern influences sound quality (GedLee theory.
Using that theory , you can see that harmonics increased is actually significant to sound quality
I will post some if our test data and you can draw your own conclusions.
What we found , using AP analyzer is a change in THD+N. (at least 1db overall)
More significant , we found the harmonic pattern to be completely changed
3, 4(2db) , 5( 3db) , 7 , 9 , 11 , 13 , 15 , 17 and 20 harmonics increased around 9-10db (using RPI4 USB3 and very similar to USB2/rpi4)
Since the THD+N is mostly dominated by noise , overall number do not change much (as I said 1db)
However ,I am a"believer" that harmonic pattern influences sound quality (GedLee theory.
Using that theory , you can see that harmonics increased is actually significant to sound quality
I will post some if our test data and you can draw your own conclusions.
Last edited:
Look.
I know DimDim for a while and he's around for a while.
He is a guy who very well understands the discussed technology.
And he also knows quite well what's going on the PI audio side.
The more I was surprised reading his misleading partially simply false post.
To me this was not just simple sloppiness. To me it made the impression that
he simply tried to shut up LinuxGeek and that based on his misleading stuff.
Something like that I'd consider arrogant/ignorant behavior.
And you bet. I'll continue to call people out on such a behavior.
If you like it or not.
Enjoy.
Last edited:
@cdsgames
* Are u running USB DAC tests? Which DAC?
* How does the I2S situation Pi3/4 look like? With isolators, reclockers, separate power rails in place?
* It's not really clear to me - reading your post - what the differences are between own USB transport, RPI3B+, RPI3 ?
* Setup? WLAN, wired, local playback, local data, streaming...
* Are u running USB DAC tests? Which DAC?
* How does the I2S situation Pi3/4 look like? With isolators, reclockers, separate power rails in place?
* It's not really clear to me - reading your post - what the differences are between own USB transport, RPI3B+, RPI3 ?
* Setup? WLAN, wired, local playback, local data, streaming...
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.