What do you think about adding more input and output channels to our DAC+ DSP?
Date
Votes
39 comments
-
Hannu Teulahti Subwoofer output to spdif would be great for 5.1 amplifier
-
nettings That would be amazing. If you can make driver hiccups recoverable, even more so :) The AudioInjector Octo does an amazing job of piping 6 inputs and 8 outputs over a stereo I2S without proper TDM support. Problem is, if you really throw the kernel out of whack, it loses track and the channels are permutated. You can recover by restarting the driver at run-time, but it's pretty impossible to _detect_ the issue. I've been dreaming for a solution that maybe adds a proper TDM clock pulse on another GPIO to the native I2S driver on the Broadcom... too timid to tackle it myself :-D
-
HiFiBerry team The Raspbery Pi just isn't designed for more than 2 channels. I know that there are hacks, but it will still be hacks. The I2S subsystem runs independent from other GPIOs, therefore you can't just use an additional GPIO to send channel information.
One option I see with the DSP is to multiplex 2 channels into one with twice the sample rate. That's basically how FM stereo transmissions work. The DSP could the invert this. Definitely not a beginners job, but it might be possible.Best regards,
Daniel -
nettings Yeah, that would be more stable than the pseudo-TDM hack.
IIRC, CoreSound did that many years ago to pipe their 4-channel microphone over an S/PDIF link - there should be an open-source ALSA driver somewhere, for inspiration.
But it's a shame the Broadcom does not support real TDM...
Although I'm not entirely sure you cannot reliably bit-bang an extra TDM clock pulse over an external GPO.. Granted, it's a bit less bullet-proof than the hardware I²S implementation, but it might just be possible, looking at the benchmarks some people posted... -
Alan Frazier I'd just like to be able to stack Amp2 hats and drive more speakers. I don't even need them to be additional channels, although that would be a nice feature, too.
-
Thomas R. I am interested in build a multi channel DSP (18 Input Channels and 36 Output Channels) for my home theater (Atmos Setup with Double Bass Array).
I like to have one central configuration board and one central power supply in this „box“. I lime the hifiberry dac+dsp (maybe with xlr plugs)
What do you think? Is it possible?
-
HiFiBerry team While it's possible, I wouldn't expect a 18 In/36 Out DSP form us in the near future. There are very few people that would need that much channels and it would be very expensive to implement this.
-
Thomas R. I know! There are solutions on the market e.g.from Trinov. The price of this solutions is 30.000€ and more.
So i dont care about the price i need to know if it is possible. If yes i will see if i can produce sell devices with your technology.
i know the market and i have the network to sell highend solutions to home cinema owners.
Maybe it males sense to split the 18 Input Channels in two or three devices... but my first goal is to realice that in one device.
-
Thomas R. How many DSP Boards can i stack on one hifiberry?
-
HiFiBerry team You can only use ONE board on a Raspberry Pi. You can't stack these.
-
Viktor Perselli It would be nice if it was just one board, but the importent thing for me would be the inputs. At the moment a lot of what I’m listening to is from my server running Roon (dac+ Pro, digi and amp 2 in different rooms), but I’m also playing CDs and LPs. What I would really like is to have my hifiberry unit to act like a preamp, and let me select between two analog, two digital inputs and also let me control the volume over my smartphone.
Best regards
Viktor Perselli
-
mjgraves Would like to have both XLR in and outs, specifically to make a SIP soft phone appliance that would connect to an analog audio mixer. Think live radio call-in show.
-
Ernest Kaempfer Hi Daniel,
I am using the DSP/DAC as an 8 channel (4 x 2 channel) xcon/eq for active speaker design with external DAC. The current DSP/DAC unit has only 3 serial outputs (Data Out_0, Data Out_1, Date Out_2) directly accessible on pin headers #6 and #3. Data Out_3 is missing from the pin out list and strictly routed to the RPi 40 pin connector (pin 38) only. It would be nice/better to have D3 available on pin header #6 as well. And since I am using the DSP/DAC as a universal input/output processor, it would be great to have more than just one I2S input (Data In_1 on P6), so Data In_2 including its LRCK and BCK accessible as well! IMHO many applications would benefit from this.
Greetings,
Ernest Kaempfer
-
HiFiBerry team Hi Ernest
thanks for the feedback. I'm not sure if we can do this in the future. Adding another 2 I2S channels could become quite complicated as this would basically mean another 6 pins and traces. However, you can configure the I2S channels as TDM with up to 16 channels per pin. This might be a way to add more channels with the existing hardware. Not sure if your DAC supports this.
Best regards,
Daniel -
Ernest Kaempfer Hi Daniel,
I guessed as much about the layout/routing issues that it may cause, so my alternative is to just tap D3 (parallel to pin 38 of RPI) and branch that off into P3 as in picture below (need to add 2 pins). Most output applications are synchronous so I2S LRCK and BCK can be used for all Data outs. Haven't looked into multi-channel TDM mode yet and if supported by eDAC. Adding an extra input I2S channel is still open for debate? (you'd need to route 3 extra traces, maybe can be squeezed in :-).
Ernest
-
HiFiBerry team It's open for debate ;-) We'll look into this. However, don't expect an update on the DAC+ DSP soon.
Let's assume, you can get a board with multiple DACs and ADCs: How many inputs and outputs would you require?Best regards,
Daniel -
Amsterdam Berry I think for people interested in making their own speakers and being able to separately control each driver it would be nice to have one dac + amp per driver, so for two speakers with woofer mid and tweeter that would make 6 separate channels with dac and amp each. That would be perfect!
See here for an outline of what that would look like:
https://therationalaudiophile.wordpress.com/the-project/Best regards,
Amos -
Amsterdam Berry PS I think stacking makes total sense. For people who would like to have a way to accurately control the drivers of their speakers it wouldn't matter if the end result would be a bit bulky. I'm excited by the prospect, hope this will become possible!
-
HiFiBerry team @Amsterdam Berry: Why would you need a 6 channel ADC? For the input you would only need 2 channels - right?
Best regards,
Daniel -
Amsterdam Berry The project I described actually is only about having multiple dac/amp channels and doesn't require any ADC channels. Rather it would require the possibility to send a different digital audio signal to all dac/amp channels at the same time, such that each driver in the two speakers receives its own (crossed over, corrected, etc.) unique signal...
-
HiFiBerry team Yes, that's what the DSP can do. It receives a stereo signal and implements the crossovers and corrections for each speaker.
Best regards,
Daniel -
Amsterdam Berry Right, so would that require one RPi with three DSP's, such that 3 separate stereo signals will be processed in parallel (woofer, mid, tweeter)? Or is it possible to use one DSP alone to send 3 stereo signals to the 6 drivers directly, meaning six output channels? And in that part case using only one DSP, would that require 3 different dac/amps, or would one dac/amp be able to handle the six signals?
I'm trying to figure out which components would be necessary to get 3 (woofer, mid, tweeter) seperately DSP modified stereo signals (ie 6 signals in total), and how those components would have to be connected to each other...
-
HiFiBerry team Hi,
one DSP can handle this. In theory the DSP used here can handle up to 48 channels. However, with the current hardware there are no 6 output channels. Even with an 2/2 channel add-on board you would only have 4 analogue output channels. This would require using 2 separate Raspberry Pi's/DSP.
Best regards,
Daniel -
Amsterdam Berry Got it. Thanks for the answers!
Best regards,
Amos -
6515cg First, a Beocreate without any annoying cracks or pop sound issues when starting up and/or changing numbers in Spotify Connect, Airplay or Bluetooth and/or using services like MoodeAudio, Volumio etc.
Second: spdif in (not toslink) and simple L/R audio in.
Solving the first issue in a new Beocreate design is the most important to me because at the moment I use other (cheaper!) sound devices because my customers won't buy it when they hear those annoying sounds problems. Although the sound of the Beocreate is a hundred times better.......
-
HiFiBerry team @6515cg: If you have problems with your existing setup, please create a new post. We need to know what software/version you're using and what DSP profile you deployed.
Best regards,
Daniel -
Sanghun Lee I have active speakers (Focal solo 6 be) and I'm using DAC+ XLR for roon now.
And. I use airplay to see the Netflix, because of the absence of input in DAC+(It has small delay, so I can see netflix but I cannot enjoy fully!!)
At least 1 input for aux or stereo input is needed for convenient use.
I'm eager to see that kind of product.
-
Ernest Kaempfer Just as an FYI,
I have used the HifiBerry DSP as starting point for a multi driver speaker design and it works great. I was able to program the DSP successfully via SigmaStudio, even though it has a steep learning curve.What helped me a lot was the documentation that ADI provides with its ADAU145x evaluation board found here: https://www.analog.com/media/cn/technical-documentation/evaluation-documentation/EVAL-ADAU1452MINIZ_User_Guide.pdf .
For all DIY'rs in this forum an essential guide to get a step by step education how to set up a project.
my 2cts,
best regards,
Ernest
-
hagbrain Hi,
the only thing Im missing is at least one "analog in (stereo)" because I got some devices that are only capable of "analog out". So if you release the board descibed int the blog (stereo analog in?) I would instantly buy one.
I use the board as standalone atm, because of issues with Spotify Connect on Volumio. Room correction 20Hz - 300Hz IIR filter and 300Hz - 20Khz FIR filter. In addition to the "analog in (stereo)" on the board would be a 2nd "Toslink in", but the "analog in (stereo)" would be enough for me.
Optional a single analog out (mono) for a subwoofer (no problem if only the DSP board can access it, because ill use a internal crossover in the DSP) would be nice to build an easy 2.1 system, even if you use the "analog out" (stereo) at the same time.
I would even test it and pay for it if the state is usable.
Best regards
Michael
-
Håvard Kråkenes This is in my opinion a perfect addition to the DAC+ DSP. Perfect for what I am looking for:
Running a fully digital preamp with a rpi DSP, and the possibility to run a RIAA through the DSP with the analog inputs.
Hope you produce this extension :)
Please sign in to leave a comment.