You can start with a simple dev board but if you want to make something that could match Amanero or I2SoverUSB you would need to design a custom board.
I belive I can just sandwich the dac pcb over the top of where the oscillators are on the STM, and just use gold plated connector pins or hard wire it. Should let me have separate boards to use the dev pcb + the issue you mentioned should be covered.
Are any boards or pcb files avaliable? I can order some from JLC, get the parts and solder it up.
Instead of stating what you believe, much of which makes clear your lack of experience in this area, probably better to ask for advice about the best way to do it low cost. I mean, you have some very experienced people here willing to help advise if only you ask.
In the case of your above quoted belief, have you ever measured the radiated EMI/RFI coming off the top of an STM chip? If you had, you might not be so willing to put your dac right on top of it.
My only point is that there is more to think about and take into account than you appear to have very much experience with so far.
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Regarding low-cost Amanero clones, as long as they work with current release Amanero firmware then they should be okay (so far as I know they can work with recent firmware). Its that real Amanero USB boards can be configured to work with an external clock (the clocks you choose to put very close to your dac chip). As Alex was trying to explain, if you only need USB then you don't need a FIFO (and all the cost and complexity associated with that). However, if you need SPDIF/TOSLINK/AES type input signals then those have to be dealt with in some way to minimize jitter problems. So, do you only need USB?
My mistake. Sorry. I should clarify that when I say I belive, I mean how I would "solve it" which quite abviously as you pointed out wouldn't be the best idea. Yes I lack experience, I am extremely new to this all. My original post is the question and this is the follow up. Sorry If I came across wrong. I expect corrections to nearly everything I say (since most is wrong), so didn't specifically word it as a question. Noted, thanks!
Have you?
With properly designed layouts DAC and USB-bridge can be sandwiched together and have SOTA performance. Much better than using devices hooked up with dangling wires.
Yup only usb, nothing else bothers me much. I can use that with all mu computers and even on the phone.
We have been through all that before. We have seen pics of how some famous designers work, and how @MarcelvdG builds prototypes.
Getting back on topic, you trust Andrea2210 would accidently sandwich it "properly"?
Yes we have but we have not seen SOTA performance out of those.
Yes of course if provided with properly designed boards.
best offer on fake Amaneros I found, which is right about 40$.
https://www.alibaba.com/x/xyie01f?ck=pdp
which gets washed by a 44$ https://www.diyinhk.com/shop/audio-...oa_cable/153-optical_spdif_output_socket-null
I imagine quality from an stm32 (I've looked into the pic32 also, everything is cloudy.) can match this without major issues.
Any advice? I think this stm should work well https://aliexpress.ru/item/10050066...x.productlist.search_results.0.53d95b32M37Aqu
It was unclear -you want to use some “finished” PCB from the online stores “as it is”, or with your own firmware, or you want to fully develop your own PCB (including the schematic, layout and firmware)?
If the finished PCB with your software, then keep in mind that in the case of XMOS, the CPU can be locked. STM32 can always be erased (I do not think that Leve2 protection is used), but XMOS has a one time programmable memory to protect the device (OTP).
If you want to create your own design (schematic+layout+firmware), then in addition to XMOS, PIC32 and STM32, you can also consider Comtrue CT7601, CMEDIA CM6631, 6632., The source code of the firmware ypou can get from it's manufacturers, but they may need some customization.
I only talked about the USB (CPU) psu - STM32 required only 3.3 V, but XMOS requires 3.3 and high current 1.0V.
In case of STM32 or XMOS with external PHY, also 1.8Vis needed.
Alex.
Last time I asked CMedia for CM66xx programming documentation to create our own firmware, my request was declined that they prefer to code the firmware themselves and do not provide the documentation.
Not exactly. That depends on the external PHY. E.g. USB3343 works with only 3.3V (i.e. same as STM32).
As I said already this kind of board is good starting point for experimenting and learning. But it is not well suited for proper USB audio as it e.g. has no on-board audio clocks. Also the layout is probably not optimal. Even as a starting point genuine STM development boards are better.
I have something, but rather old (~9-10 years). If you want - PM me you email.
Agree.
I mostly used 3318.
I am open to any solution so long as it's cheap and delivers quality.
Noted. I like the CT7601 option I'll look into it.
Understood. Many thanks for explaining. Forming voltages shouldn't be an issue. My take is dc-dc as step one and linear stabilization as step 2 for proper supply.