Hi, The DAC8X is a really interesting new addition to the Pi ecosystem but not quite right for me in that it provides only unbalanced outputs (and only on jacks, which I always prefer to avoid). A version providing either balanced outputs on some sort of header (since 8 XLR connectors would clearly be impractical), and/or an ADAT 'lightpipe' output would be great. Even the simple addition of a header providing access to the present unbalanced outputs would be a real help in that it would aid the addition of a (homemade) balanced line driver board, or just alternative connectors to the jacks. Best, Ian.
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HiFiBerry team There will be probably more multi-channel products in the future. What? We don't know yet, so don't expect something soon.
One thing I can comment on already is ADAT: This won't happen! ADAT is basically dead. The last ADAT transmitter chip that was on the market is end-of-sale for more than 5 years.
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Ian I don't think it's right to describe ADAT as 'basically dead'. Whilst dedicated tx/rx chips may have been dropped (although see here: https://www.coolaudio.com/features-page.php?product=V1401), respected manufacturers like RME continue to provide extensive ADAT support in their new products, eg: https://rme-audio.de/m-1620-pro.html. And, at the lower end, I believe that Behringer's ADA8200 continues to sell very well.
I don't know for sure but imagine that these days the likes of RME use some sort of programmable logic to implement the ADAT protocol, and, indeed, that the increasing prevalence of this sort of approach likely contributed to manufacturers dropping dedicated ADAT chips in the first place. For an example, see here: https://www.xmos.com/download/AN01004:-ADAT---Replacing-Wavefront-AL1401-402-with-xCORE(1.0.1rc2).pdf.
In fact, I wouldn't be surprised if you could even emulate ADAT tx/rx with the state machines on a Raspberry Pi Pico. If I can ever find the time I'll have a go myself!
I appreciate that there are newer technologies for carrying multiple channels of digital audio, notably MADI and Dante, neither of which I have used so far, but there remain a lot of ADAT-equipped devices in general circulation, which presumably is why the likes of RME continue to support it. That and the fact that audio engineers understand and trust it, which in turn is because it happens to work very well.
RME's products are wonderful but the company doesn't (won't) support Linux. This is a crazy state of affairs for an outfit that is so engineering-based, but the fact is that Linux was too late to the game and so remains largely excluded from the pro audio world. Maybe this will change with time and maybe increasingly powerful Raspberry Pis will be a part of that. I hope so. But if it is ever to happen it will require high performance multi-channel interfaces, with balanced i/o and good Linux drivers.
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aris A balanced version of the DAC8x with a D-Sub connector would be ideal to connect directly to power amps.
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daniel ADAT is alive and well in electronic music production studio environments! Just this year two new highly-anticipated ADAT modules for Eurorack were released to much applause: the Expert Sleepers ES-10, and the Boredbrain Optx v2, both offering 8in/8out and retailing for $350+. It would be wonderful if a HAT that provides some similar functionality could be offered for a significantly lower price.
miniDSP offers a popular ADAT-USB interface called the MCHSTREAMER as well. There's a market for this stuff!
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Matthew Dovey I agree that that the reports of ADAT's death are greatly exaggerated (to misquote a misquote). My audio interface is the AudioFuse 16Rig which supports ADAT (but not SPDIF :-( ), and that has only been on the market for just over a year.
As others have said it is probably that it is now more cost effective to implement ADAT on a microcontroller or FPGA rather than on dedicated silicon. If anything ADAT is somewhat simpler than SPDIF.
During lockdown, I got into FPGA programming, and a while ago I created an PMOD adapter so that I could play with ADAT/SPDIF (https://github.com/mdovey/pmod_optical). For those not familiar with it, PMOD is a simple GPIO interface which Digilent (and others) use for connecting devices to FPGA development boards (Digilent even does a PMOD hat for raspberry pi - https://digilent.com/shop/pmod-hat-adapter-pmod-expansion-for-raspberry-pi/).
I've managed to rig up a FPGA development board to do a basic ADAT/SPDIF converter. I'm currently working on making it a standlone pcb (and less heath-robinson), and will make the code available. Assuming that works(!), I'd also consider a small production run if there's sufficient interest and the economics work out.
Matthew -
Ian In case anyone hasn't noticed there is now a balanced version of the DAC8x available:
https://www.hifiberry.com/shop/boards/hifiberry-studio-dac8x/
https://www.hifiberry.com/docs/data-sheets/datasheet-studiodac8x/Matthew, really interested to read your post - sounds like you're getting up to some great stuff there. I've not got into FPGA programming myself but would love to - just a question of ever finding the time. Interested to note too, from your github link, that you're using kicad. I've got into that over the last year, and it is amazing. But I'm wondering now if Fritzing might be more suitable for my modest needs. Have you had any experience with it? (Sorry, this is getting a bit off-topic).
Ian.
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Matthew Dovey I think I did look at Fritzing briefly before settling on Kicad. One thing I've not properly fathomed is the simulator support, and Fritzing does look as if it would allow you to try out a circuit without having to physically breadboard etc.
However, if I recall it was still in quite a early stage of development when I looked so if you've spent more than an hour looking at it, you are more experienced than me!Matthew
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HiFiBerry team Just a short reminder: The forum is about HiFiBerry products. I recommend to move other developments to another platform.
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