Ghoostknight Posted January 25, 2022 Share Posted January 25, 2022 Hello, i already made a similar thread over on DIYAudio (tho it didnt gather any results yet) https://www.diyaudio.com/community/threads/modded-rpi4-board-for-better-sq.381877/#post-6917459 basicly the goal is to make a very light musicstreamer with as little noise and best SQ as possible :) In short those are the ideas i had so far 1. replace the DC/DC Converters, one step further would be to provide the different voltages directly but i think thats a step too far, and someone also posting here said good dc/dc converter do make nearly the same effect (maybe add filter capacitors too?) 2. filter capacitors for usb, maybe as a sort of decoupling for all usb devices drawing power? 3. remove the BT/WIFI modul or disable it in some way, since even if disabled in config it still actively transmits 4. replace the clock(s) for better ones 5. remove the headphone amp circuitry and maybe other unneeded stuff? 6. add more filter/decoupling capacitors over all 7. underclock for less noise 8. adding shielding? something like the stationpi trys to accoumplish https://www.audiophonics.fr/en/raspberry-pi-and-other-sbc-accessories/ian-canada-stationpi-pre-assembled-adapter-pcb-for-raspberry-pi-and-audio-modules-p-14868.html , the i/o board has enough room to basicly do the exact same thing, ground plane under the CM4 and grounded heatsinks for the cm4 is probably also a good idea 9. using isolators to attached usb devices (bt and wlan dongle and maybe storage, tho my goal is to get a nas) and network 10. i had good expierence with diy chinch connectors/endcaps filled with turmaline, i had the idea todo the same for USB (and maybe other things but i will see) i think the CM4+ I/O Board would be a very good alternative to the normal RPi4B since the CM4 modul can be bought without wlan/bt module and with inbuilt emmc (also a good thing is if i break something (cm4 or i/o board) its cheaper to get a replacement :D) thanks to tim curtis for the idea :) https://www.reichelt.de/raspberry-pi-compute-modul-4-4gb-ram-32gb-emmc-rpi-cm4-4gb32gb-p290538.html https://www.reichelt.de/raspberry-pi-compute-modul-4-io-board-rpi-cm4-io-board-p290556.html (probably paired with this usb 3.0 https://www.waveshare.com/product/pcie-to-usb-3.2-gen1-b.htm) i plan to use the pcie slot for usb 3.0, just like the RPi4B, so the usb 2.0 hub can be used only for a dac one extension hat that got my attention was this one: https://www.thanksbuyer.com/ustars-audio-pi4-clock-system-clock-board-without-ocxo-for-raspberry-pi-4b-change-crystal-oscillator-73301?sort=p.model&order=DESC&limit=25 it basicly replaces the 3 clocks on the rpi4 with a single 10mhz high quality clock (and i think its probably a good thing all clock signals are derived from a single clock) tho im unsure if its also completly combatible with the CM4, since i dont find clock values on the web i have to wait till i get mine to check i should also say, i know about the allo signature but from my understand it mainly focuses on adding filter capacitors and not really more and the usb 2.0 output still shares the bus with network (because it uses the rpi3) and i wanna have a little modding/diy fun :) chipvn 1 Link to comment
chauphuong Posted January 25, 2022 Share Posted January 25, 2022 Buy an Allo Usbridge Signature, replace CM3+ with CM4, change clocks and it would be wonderful. Link to comment
Ghoostknight Posted January 25, 2022 Author Share Posted January 25, 2022 9 minutes ago, chauphuong said: Buy an Allo Usbridge Signature, replace CM3+ with CM4, change clocks and it would be wonderful. those adapter makes the cm4 combatible but i think the usbbridge signature would still be limited since most cm4 features wont be used (seperate usb and ethernet for example) and i kinda dont wanna buy it that late in fear a updated version gets released soon, kinda wondering why they didnt come up with a better version yet Link to comment
chauphuong Posted January 27, 2022 Share Posted January 27, 2022 Usbridge sig has separate usb and Ethernet feature. Link to comment
the_bat Posted January 27, 2022 Share Posted January 27, 2022 On 1/25/2022 at 7:20 PM, Ghoostknight said: kinda wondering why they didnt come up with a better version yet Mainly because the Pi4 and CM4 are pretty well unobtainable Link to comment
Ghoostknight Posted January 27, 2022 Author Share Posted January 27, 2022 1 hour ago, the_bat said: Mainly because the Pi4 and CM4 are pretty well unobtainable are they? i hadnt problem finding them in stocks, tho it was like early 2020 unobtainable 12 hours ago, chauphuong said: Usbridge sig has separate usb and Ethernet feature. hmmm are you sure? maybe ethernet has a own chip but im pretty sure it and the usb chip end up in the same bus because the PI3 has not any buses to spare pretty sure it looks like this: tho i guess they did a good job since noone is complaining about it but in the end i dont feel like spending 250€ on just the board and rather mod the 35€ i/o board myself including all cm4 features like: 1. emmc 2. no inbuilt wlan/bt 3. acting kinda like a stationPi with a added shield 4. completely standalone usb2.0 bus 5. you can add a standalone usb 3.0 bus for storage/other usb devices or other pcie stuff if you feel like it 6. having all I/O on one side is kinda a big deal if you wanna put everything in a 1/2 HE rack case like me i think those are the main advantages (tho i really like having a usb 2.0 hub JUST for the dac, i actually kinda wondering if i could skip the usb chip completly and go directly into the Pi since i just need one port, this would also cut the need for a better clock for the usb hub chip, but then it depends on the Pi bus/clock Link to comment
Ghoostknight Posted January 27, 2022 Author Share Posted January 27, 2022 One big advantage of the official I/O Board is also that schematics are available, i think with that additional filter capacitors are quite easy to add, specially because my electronic knowledge isnt that good (just add them where already "capacitor banks" exists in the schematics) (beside that i couldnt find any boards that fits my needs as good as the official i/o board anyway) so i probably stay with the cm4+i/o board idea, i will keep you guys updated with pics etc once i have the stuff here :) would still be nice to hear some opinions "on-topic" :) Link to comment
Ghoostknight Posted November 4, 2022 Author Share Posted November 4, 2022 i wanna dig this up again since i probably start soon! (like 1-3 months soon) Since the Raspberry Pi 5 isnt in sight the plan hasnt really changed New things to consider: The CM4 IO Board actually can skip the whole usb 2.0 controller in "otg mode" where a micro usb socket is directly connected to the CM4 usb 2.0 lanes instead of the USB 2.0 Controller, i will definetly try this out for the DAC (normally this is just used to flash the emmc flash) I will probably rip out the complete power section of the CM4 I/O Board and power it directly with LT3045 Power regulators, there are 3 main voltages needed: 5V, 3,3V and 1,8V normally the PCIE Express socket needs 12V too but i will use this USB Hub https://www.waveshare.com/pcie-to-usb-3.2-gen1-b.htm which steps down the 12V to 5V anyway, so i will also skip the step down regulator and power it with 5V directly the 1,8V are needed for the CM4 itself So ideally i can make a 5V Input from a Linear power supply and step down the 5V to 3,3V and 1,8V which is probably the most efficient way of doing this Thats it for now, i will keep you guys updated Any Ideas are still very much appreciated! :) Link to comment
AudioDoctor Posted November 4, 2022 Share Posted November 4, 2022 I thought about putting a JCAT USB card in the pci slot of one of these and using it as an NAA for HQPLayer. The problem I ran into was I would need to develop a case for it myself and I have other outstanding solutions already so I decided it wasn't worth it. It is a neat idea though. No electron left behind. Link to comment
Popular Post Ghoostknight Posted November 4, 2022 Author Popular Post Share Posted November 4, 2022 13 minutes ago, AudioDoctor said: I thought about putting a JCAT USB card in the pci slot of one of these and using it as an NAA for HQPLayer. The problem I ran into was I would need to develop a case for it myself and I have other outstanding solutions already so I decided it wasn't worth it. It is a neat idea though. Hmm yees such usb card would be also worth considering, i just dont know if its even better than directly connecting to the usb lanes on the PI (with the otg port) since those are mainly made to improve a really noisy PC The thing that keeps me going is this: raspberry pi has some nice distros for streaming and already a stock pi sounds far superior to my normal PC Unfortunaly i dont have any high price streamers to compare tho :( would be really interesting to try one out sonodynesrp205 and chipvn 2 Link to comment
Popular Post Ghoostknight Posted December 8, 2022 Author Popular Post Share Posted December 8, 2022 i settled on this board now: https://www.waveshare.com/cm4-to-pi4-adapter.htm its quite new on the waveshare catalog benefits compared to the Official I/O Board: - smaller footprint, short traces - no "huge" power section, it can be powered with 5V natively, there are still a 3,3V(for general purpose stuff of the board, like powering LEDs) and 1,2V(for usb controller) - built in usb controller i would have added anyway to the IO Board, unfortunaly its not easy upgradeable now but i hope to just use general purpose peripherals (like SSD, Wlan/BT Stick) with it - i already received it and it looks quite well (atleast optical) made compared to other boards i saw in person -- i also bought these boards: https://www.ebay.de/itm/174216558760 and 25 and 54mhz squarwave txco clocks: https://de.aliexpress.com/item/32670224530.html to exchange the 3 clock signals -- i probably will use these boards https://www.ldovr.com/product-p/lt3045-1a0g.htm to exchange the 2 regulators on the waveshare board and to power the clocks, hopefully i can do this while just using a 5V input, so i stay universal with input power supplys which im not sure yet what to settle on, some ian canada boards look very nice (i specially look at the battery power supply right now) unfortunaly i found out that the cm4 (and raspberry pi 4) uses a kinda properitary voltage regulator which offers all 4 voltage rails on one chip while communicating with kernal drivers over i2c, so its pretty much not changeable, maybe i find a solution to atleast improve noise on those voltage rails with added capacitors -- but i will first compare the "stock" waveshare board and cm4 board (the cm4 board is on its way too) with my current raspberry pi 4 streamer and will add stuff "on the go" piece by piece, i also wanna add all this to a nice alumium case but i will probably first test stuff but plans stand "kinda" or atleast this is how it looks right now :) blueninjasix and Mr Morris 2 Link to comment
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