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Improve Raspberry 4 streamer

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officialsm

officialsm

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Can I ask what you mean by improve performance? In keeping with the objectivist bent of ASR, it may be hard to make any improvements that you will discern as audibly better. But there may be ways to improve its SINAD (THD+N) rating that may still be something you want to achieve. I for one do not discount the value of increased self satisfaction of knowing your gear can achieve the cleanest signal possible. For me it is akin to tweaking my Porsche to incrementally improve its zero to 60 mph time although that will have no perceptible impact on how quickly I get to work each day (purely hypothetical analogy though, since I drive a Prius).

If i can do something to have better audible improvements.
 

ctakim

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If i can do something to have better audible improvements.
Got it! I'll let others weigh in to see if there is something more you can do that can make audible improvements. But the RPi4 is viewed as an audiophile grade music streamer that, when paired with a quality DAC, can give outstanding results!
 

lshivamber

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The RPI4 is already a great streamer.
If you are looking for ways to improve outside of audible improvements, then one feature I am interested in is the ability to trigger a DAC to turn on
 
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officialsm

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To have a linear power supply instead switching could help? I have a 5 ampere switching one at the moment.
 

SolderSurfer

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I am considering building a Raspberry 4 streamer with a DAC hat or separate board of some kind. It would be nice to have a small combined streamer and DAC.

I believe one of the main issues with having a DAC in the same box is perhaps power supply noise coming from the wall USB switching power supply or the Raspberry microprocessor. I am thinking of powering the DAC separately using a rechargeable battery with a linear voltage regulator. There might be an off the shelf USB power pack that would work. Or maybe an LT3045, or similar ultra low Noise switching regulator that separately powers the DAC hat. Has anyone tried this separate power supply approach?
 

somebodyelse

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I am considering building a Raspberry 4 streamer with a DAC hat or separate board of some kind. It would be nice to have a small combined streamer and DAC.

I believe one of the main issues with having a DAC in the same box is perhaps power supply noise coming from the wall USB switching power supply or the Raspberry microprocessor. I am thinking of powering the DAC separately using a rechargeable battery with a linear voltage regulator. There might be an off the shelf USB power pack that would work. Or maybe an LT3045, or similar ultra low Noise switching regulator that separately powers the DAC hat. Has anyone tried this separate power supply approach?
Off the shelf USB power packs use a switching regulator to make 5V from the battery voltage. Many of the DAC boards use multiple regulators, including a switching one to make the -ve voltage rail for the output opamps. You need to look at the specifics to see if a separate PSU will improve anything.
 

TheBatsEar

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Hi, with room 21-22° C the RAsp cpu temperature is around 55-58° C

Maybe just add a metal block between CPU and case, that way your temp will go don't to maybe 5 or so °C over room.

No need to reclock when you use USB.

If you want to do better, add a MiniDSP between the RPi and the DAC and compensate your speakers/room before going analog.
 

Katji

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I would like to improve performance, if possible. How can i do? Thinking add some reclocker or dac board or somwthing else?

I think OP was thinking of incorporating a DAC with the streamer, so... RPi HAT DAC, Khadas board...?

Heatsink...well, that 8-10mm face plate is a massive heatsink, just not where you would need it. No problem, though, easy to sort something out,
 
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officialsm

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Do you think could be useful to add heat sink thought i'am using this kind of enclosure?
 

somebodyelse

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Do you think could be useful to add heat sink thought i'am using this kind of enclosure?
If the Pi isn't going into thermal throttling then there's probably nothing to worry about. You could try adding a heat transfer pad between the Pi and the bottom of the case.
 

quattr0

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Do you think could be useful to add heat sink thought i'am using this kind of enclosure?

My Pi4 also has HAT so I assume it will generate more heat than yours....Room temp is 24C. Pi is streaming Moode/Roon for 1 hour+. I have the heatsinks on smaller chips and a thermal pad on the CPU. Here are the temp.

So...if you will have the heat transfer pad and heatsinks for smaller chips, my guess is it will certainly help but not much. The Pi4 won't throttle until 80C i believe.


PiTemp2.JPG


20210427_101825.jpg
 

robca

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Re: thermal pads. Proper thermal pads are a good thing to have, if you also have a heat sink.

Just a heat pad as it seems to be the case in the picture above, would actually decrease the efficiency of the processor metal top in getting rid of heat (unless that pad, in turn, gets into contact with metal, even a PCB copper plane)

Also, keep in mind that the majority of the cheap Raspberry Pi heat sinks sold on eBay/Aliexpress/Amazon are shipping with just double sided 3M pads that act as insulators. Buy the cheap heat sinks, throw away the provided pads, and use a thermal epoxy (sometimes sold as thermal plaster) or a real thermal pad to keep them in place.

You can also make your own thermal epoxy using normal epoxy with thermal paste mixed into. Or even silicone sealant (not the one that smells like vinegar, that will risk corroding the PCB) and thermal paste. The ratio determines how strong the bond is, vs how good the thermal transfer is. Since those devices are used in a place with no harsh vibrations, there's no need for a super strong bond, and it's actually better to have a small amount of epoxy so that it can be removed in the future
 
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officialsm

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Re: thermal pads. Proper thermal pads are a good thing to have, if you also have a heat sink.

Just a heat pad as it seems to be the case in the picture above, would actually decrease the efficiency of the processor metal top in getting rid of heat (unless that pad, in turn, gets into contact with metal, even a PCB copper plane)

Also, keep in mind that the majority of the cheap Raspberry Pi heat sinks sold on eBay/Aliexpress/Amazon are shipping with just double sided 3M pads that act as insulators. Buy the cheap heat sinks, throw away the provided pads, and use a thermal epoxy (sometimes sold as thermal plaster) or a real thermal pad to keep them in place.

You can also make your own thermal epoxy using normal epoxy with thermal paste mixed into. Or even silicone sealant (not the one that smells like vinegar, that will risk corroding the PCB) and thermal paste. The ratio determines how strong the bond is, vs how good the thermal transfer is. Since those devices are used in a place with no harsh vibrations, there's no need for a super strong bond, and it's actually better to have a small amount of epoxy so that it can be removed in the future

So you are suggesting to put a heat sink on top of Rasp with good thermal paste. Correct?
 

Kegemusha

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I would test the DAC HAT and use the output from there to the Cambridge to see if the sound is better .
Or use a USB DAC dongle that measures good and connect it to the Cambridge. Otherwise I think you are fine

What is that you feel you need to improve if I may ask? Is not the sound good from the Cambridge?
 

robca

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So you are suggesting to put a heat sink on top of Rasp with good thermal paste. Correct?
Thermal paste by itself would not be enough to keep the heat sink in place, unfortunately. If you have epoxy glue available, mix a tiny amount of it with thermal paste and use it to glue the heat sink in place (I would use 2-3 parts of thermal paste for 1 of epoxy, so that it would be relatively easy to remove if you wish. Or the same ratio of sealant and thermal paste. You won't need a lot of strength in the glue, and many other glue mixes will probably work equally well. All you need is a bit of adhesion on top of the thermal paste. Or buy a proven good thermal pad from a reputable source (e.g. Sparkfun in the USA).

Or, even better, buy one of those finned aluminum cases, where the case itself is the heat sink and retained in place with screws, and then you can use thermal paste. Just be aware that most are not that well designed, see my review on the one I bought from Amazon https://smile.amazon.com/gp/custome...=cm_cr_getr_d_rvw_ttl?ie=UTF8&ASIN=B07TZQHXZ6 I use that case purely as a passive case, since mi RPi is not fully loaded, so I disconnected the fans. Can use the fans at 5V or 3.3V (the latter quieter and still plenty good cooling). Overall, I'm really happy with that case now

EDIT: just in case, and since I mentioned it before, I also used this to glue heat sinks for a variety of uses https://www.ebay.com/itm/174734313048. Please note I'm not suggesting to use that specific seller, just the first one I found when searching. It works well and it's cheap, strong enough even in case of vibrations, and decent heat transfer (in any case, you use just a very, very thin layer, ideally you want metal to metal contact). The only downside is that once you open the tube (and it's a tiny tube, just in case it's not obvious from the picture), it starts hardening and within a month or two is mostly all gone.
 
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JoachimStrobel

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Hifiberry argues, that an internal DAC minimizes digital conversions
https://www.hifiberry.com/blog/techtalk-external-dacs/
They may have point. On the other side, an Apple USB-C 3.5mm DAC is cool and minimalistic. Everything between these solutions carries the danger of approaching the glamour of a pimped Opel Manta (sorry, no translation available).
 

Gekel

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Hi,
i'm using a 4 GB ram Raspberry 4 with Moode Audio for streaming. Output throught USB to CXA81 integrated dac amplifier.

Noob questions here,correct me if I am wrong. You store the raw data (FLAC, WAV, MP3 files) on a NAS and use the raspi to read them, transcode/transform the data to DSD256 and push it to a CXA81 over the USB port? Is there anything special needed (linux program/service/...)?

And because you look for improvements - why? Slow indexing of data or bad sound quality/stuttering sound/...?


I tried to find any information about this, by my Google Fu failed so far and it's the first time I find any info using a Raspi with an CA amp.
 
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