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A revolution in audio communications. The surround sound card (for the Raspberry Pi) which seemed impossible, but now it is done !
A revolution in audio communications. The surround sound card (for the Raspberry Pi) which seemed impossible, but now it is done !
A revolution in audio communications. The surround sound card (for the Raspberry Pi) which seemed impossible, but now it is done !
150 backers pledged AU$ 14,404 to help bring this project to life.

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    1. Missing avatar

      Lyonel on


      In case we need only two balanced inputs / outputs, can we use this type of preamp with the octo card?

    2. Flatmax Studios 6-time creator on

      Hey Mike,

      That is pretty bad isn't it. As of today I think all of the Amazon USA shipments have left their warehouses. I can't believe they didn't package that better - yep, they are charging us more then we collected for shipping !

      Let me know how things go w.r.t. the broken item, I am sure that we can replace it for you if it doesn't work.

      Thanks for your understanding as well.

    3. Mike Clark

      I may have the same issue as Gregory- I just received my package today, and it only contains one unit, with a shipping document that lists only one as well.

      And... sadly, the shipping is very poorly done- it was just a minimal padded envelope, the box that contained the actual board was smashed and torn open and the parts scattered all around the envelope. I will try to test it shortly to see if it needs to be replaced. Shame on Amazon for providing such a poor effort, I hope you didn't pay them a premium for actual good service.

    4. Flatmax Studios 6-time creator on

      Hey there Gregory, Yep, I just looked at Amazon. I think they are going to ship multiple packages to you over the next few days. Their system says that the quantity is 3 and that this particular shipment contains 1 unit. Lets check back in in a few days and see what they have done in follow up.

    5. Missing avatar

      Gregory M. O'Drobinak on


      I just received a notice from Amazon here in the US that my order was shipped.

      However, my pledge was for 3 boards [unbalanced] and the shipping docket from Amazon seems to read as just *one* unit!

      Here is the shipping docket text:
      Qty Item
      1 Octo 8 channel sound card for the Raspberry Pi

      Since the part number [SKU] shown does not exist on Amazon I have no way to look this up to see the board count. But since the quantity shows as '1', I can only assume that a mistake has occurred at their shipping point.

      Can you please let me know what is going on and what the actual quantity of units is being shipped?

      If they are sending me only one unit, then this matter needs to be rectified quickly, as my pledge was for three units.

      Thanks very much for your help!


    6. Flatmax Studios 6-time creator on

      Hey Benjamin,

      Yes, this will happen. Our plan is as follows :

      For USA backers : We have shipped from China to Amazon USA, waiting for the shipment to arrive there. Once on the shelves we will take a day or two to ship out from there to backers.

      For European backers in the Amazon UK catchment : Amazon UK have received the shipment today. We have begun the process or creating fulfillment orders. The pledges will go out from Amazon UK to you in the next few days.

      For all other backers : For those of you who gave your phone numbers with the original survey, your shipments have left China a few days ago. They will take between 3 and 5 weeks to arrive to you. For those of you who gave the phone numbers more recently, we expect you to receive the items 3 to 5 weeks from our receiving of your phone numbers.

      All of the backers who will be delivered by Amazon, you should receive an email from them with your tracking information.

      All other backers will receive tracking information from us in the next week or so.

    7. Missing avatar

      Benjamin Schneider on

      Hey Guys,

      just a short question on shipping:
      Will a backer be notified if his reward has been shipped, and will one receive a tracking number?

    8. Flatmax Studios 6-time creator on

      Hey everyone,

      Karl from China is contacting certain people for shipping detail reasons. We are chasing people (over email) who didn't include their phone numbers in the survey. If Karl contacts you, please respond on email or to me on this site with that detail.

    9. Flatmax Studios 6-time creator on

      Hey Stewart,
      Thanks for the suggestion. Could I persuade you to open this discussion on the audio injector forums ?

    10. Missing avatar

      stewartjm on

      Have you investigated compatibility with any other pi-alike SBCs? One in particular that would be pretty nifty is this one: Supposedly it does have an i2s port, though it may not currently be enabled(whatever that means).

    11. Flatmax Studios 6-time creator on

      Hey Paul,

      Hope to post and update today or tomorrow with images of the RCA version of the Audioinjector ... stay tuned !

    12. Missing avatar

      Paul on

      Hi Matt
      We've got April, all those bad humour April One jokes behind us again.
      How's the project going?

    13. Flatmax Studios 6-time creator on


      The Octo doesn't have amplifiers on board, only preamps. You will need to amplify the audio to use them with passive speakers. Alternatively you could purchase active speakers, rather then purchasing an amplifier.

    14. Missing avatar

      Danijel on


      I am planning to couple passive low cost speaker directly to octo. Is that possible or driver is mandatory? In case if this is possible what characteristic should speaker have?

    15. Flatmax Studios 6-time creator on

      Hey Danijel,

      If you want to use the Octo for an active crossover, then you can also choose nice drivers which will work well together.
      Whether you're building an active speaker or buying one off the shelf, make sure the amp can driver the impedance of the speaker (normally 4 or 8 Ohms).


    16. Missing avatar

      Danijel on

      What would be the optimal loudspeaker (characteristic) for use with octo?

    17. Missing avatar

      Paul on

      Thanks Sergey, Matt.
      I've been after the same thing, an update on fulfillment I guess.
      Thanks Matt. Looking forward to getting my hands on a unit!

    18. Flatmax Studios 6-time creator on

      Hey Sergey,

      Thanks for your support.

      We have already gone into manufacture for the boards and RCA breakout boards. The TRS boards are in the final stages of design.

      I will send out surveys over the next few days. These surveys will be requesting your delivery address.


    19. Missing avatar

      Sergey Shupilo on

      Greetings. I'm newbie on kickstarter, so i know nothing regarding how it goes after the campaign is over, how much to wait, so... Can you please share information regarding the status and/or when the product is gonna be shipped to backers? Thank u very much.

    20. Flatmax Studios 6-time creator on

      Hey everyone,
      I have setup a forum to support this community and this product.
      We can talk more easily and freely there, feel free to send messages and have discussions there :…

      Feel free to comment here as well if you like.

    21. Missing avatar

      James Mansion on

      Commenting to myself again, I always press Return too early!
      From a software point of view,its pretty easy to load raw bits from a CD, transform for crossover or room correction, upsample. Then you get the question of volume control, because it seems that you can't rely on AV receivers to do the volume in analogue after DAC, and also few of them support the optional time resynch feature. HDMI seems to have a reputation for jitter that is even worse than SPDIF but the optional feature is there to improve things and there are lots of clock recovery systems like you get for SPDIF. It seems untapped to me - everyone has HDMI output now. Something that can take HDMI PCM, make a stab at recovering a reasonable clock, isolate from the computer's grungy ground, and emit lovely analgue would be just great. I'm everyone who appreciates such things would be pleased. Both of us, even!

    22. Missing avatar

      James Mansion on

      You can do 8 channel PCM over HDMI, uncompressed, at least 24/96 from memory. But yes, it would be a different thing entirely. ALSA should give access in most cases. I've found it can be picky if it thinks there is no display, but there is an audio channel sink.
      Sure I think the voltage controlled gain could go there, ideally for unbalanced as well. I would think control over USB would be handy. I'm suspicious of the software gain on some of the DAC systems, it might be in the digital domain.

    23. Flatmax Studios 6-time creator on

      Hey James,

      Thanks for the suggestions.

      Regarding analogue volume control - it is a really nice idea. Perhaps these types of analogue volume controls can be injected between the custom breakout headers and the final balanced or RCA breakouts ?

      I have checked out the HDMI options. Unfortunately to do HDMI with multichannel, they all use compressed formats such as DTS and others. The chips are very expensive and require licensing of some form or another. For that reason, using HDMI audio extractors is expensive and probably suitable for a different project.

      Those amps look sweet !

    24. Missing avatar

      James Mansion on

      Actually, there is a product I really want. Currently I take a stereo DAC into a miniDSP 2x4HD and then I use an Audiolab 8200AQ in bypass to do passthrough volume control before my power amps and DIY active speakers. Its a faff.
      What I'd really like is an add-on that does this:
      with one of the new buffered reclocking HDMI chips in front of it and a decent buffer amp stage.
      If the volume management can be done with USB or serial (I'm thinking Arduino Leonardo here) then we have a way to use many many PCs etc to generate 8 channel audio in software having done frequency shaping and crossover, and a way to run the gain without nasty digital effects. And the DIY active community will be Very Happy - and possibly the surround PC crowd too.

    25. Missing avatar

      James Mansion on

      Hi, the amps are:……
      There are others but these are reasonably well-known, especially the Hypex.
      The bottom line is that a complete active preamp/player/crossover system looks rather tempting. A 4-out board for RPi would probably sell, its annoying to have to consider HDMI.
      Maybe that's the trick - for RPi and other PCs and videa/SBC cards: take HDMI audio in and reclock it to RCA or balanced. MiniDSP do something like that, but its a bit spendy and they have a reputation for poor PSU design (at least in snotty hifi circles) if I remember. The 2x4HD I have is fine, to be honest..

    26. Flatmax Studios 6-time creator on

      Hey James,

      External DC power is a possibility. I could add DC barrels to the balanced boards, which would allow you to plug in your own supply.
      Not sure exactly which amps and what type of connectivity you are referring to.

    27. Flatmax Studios 6-time creator on

      Hey Michael,

      Glad you are happy with TRS, yes they are balanced. I was also thinking that TRS to XLR cables would do nicely !

    28. Missing avatar

      James Mansion on

      If there was anything I'd want, it would be a way to provide top notch DC power.
      I'm using a miniDSP 2x3HD at the moment and it sounds OK, but you'll find plenty of people who are sniffy about the power line filtering etc.
      And the other thing I would like, would be an internal breakout to hook up the outputs directly to amps from Hypex, LCAudio and the like. Maybe even Aksa (pricey though).

    29. Missing avatar

      Michael Pirker on

      Hi, sorry for responding so late. Thanks for your question from Jan16th. TRS terminated connectors should be good. You will deliver balanced outputs? I did use such already in the past, often customized cables for specific purpose. Usually I will add TRS to XLR converter cables with balanced output and plug the XLR cable/microphones.

    30. Flatmax Studios 6-time creator on

      As we approach streatch goal #1, we are getting ready to announce the next set of stretch goals. Thinking along the lines of 3D printable face plates to cover the connectors and make it easy to attach to your boxes/projects.
      Wondering whether anyone has other ideas concepts which are appealing to most people here ?

    31. Flatmax Studios 6-time creator on

      Hey Paul,

      Thanks for the lead, I have registered with them and begun the process for starting a topic there. Incidentally we have had users of our other Pi sound card work out how to build Volumio with Audio Injector support built in !…

    32. Missing avatar

      Paul on



      Keep up the hard work Flatmax, you're doing very well!

    33. Flatmax Studios 6-time creator on

      Hey stewartjm,
      Thanks for the leads. I have now posted in and begun the moderation process for
      If anyone else has good leads please post or let me know !

      thanks again

    34. Missing avatar

      stewartjm on

      Two audio/music forum communities that might appreciate being aware of this kickstarter:

      I searched both and didn't see a specific mention of the octo yet. There are good search results for raspberry pi and kickstarter campaigns on both. So a tasteful post would probably be appreciated.

    35. Flatmax Studios 6-time creator on

      Hey Paul, sorry about that !
      I haven't mentioned it but I am doing everything to promote this campaign as much as possible. It is difficult for me to remember exactly where I have been putting the word out.
      I have found forums to be great for attracting interest ! Thanks again for your help. Marketing is very relentless work !

    36. Flatmax Studios 6-time creator on

      Hey Kyle,
      The cs42448 datasheet states that power consumption is around 600 mW. That is roughly 80 mA from the 5V supply and 61mA from the 3.3V supply. This represents a total of around 120 mA from the 5 V supply.

      The RCA breakouts add no extra power requirements.

      The TRS 1/4" balanced breakouts use NE552 opamps.Their current draw is around 10 mA from a 5V supply per dual package. If you use the output balanced breakout, then it will consume around 80 mA . If you use the input balanced breakout, then it will consume around 60 mA.

    37. Missing avatar

      Paul on

      Haha @Flatmax ... I just joined up at diyaudio and was about to post there about this Octo when the 'similar subjects' forum check scanned for posts and found you'd already posted there! I guess you overlooked that from your list of promotion? :) LOL. No problems.

      +1 for Kyle's question BTW. Does the card have much of a power requirement given it doesn't include an amp?

    38. Missing avatar

      Kyle on

      Is there any information about the power requirements/consumption of the card? It would be useful information to have when considering power supply/UPS options for portable/automotive power.

    39. Flatmax Studios 6-time creator on

      Thanks for pledging James.
      The chip is the cs42448 codec, here is a link to the manufacturer data sheet :
      Here is a link to the manufacturer's page :

    40. Missing avatar

      James McCanna on


      I pledged today and I have looked for the underlying chip used here? Can you tell me or show me where to look? James

    41. Flatmax Studios 6-time creator on

      Hey Paul, sorry for the late reply, just got back from a week in China.

      Thanks for posting to Max2Play. I have posted a link on the raspberry pi forum [1] below. I have also posted a few times on the pi reddit group, sent a tweet or two as well as facebook posts !
      Another forum I have hit is

      To help us get to this first stretch goal and possibly a few more, it would be great to have people sharing the project on social media.


    42. Missing avatar

      Paul on

      Hey flatmax can you list the marketing you've already done to avoid us duplicating?
      I posted to a forum for the Max2Play software.
      Has anyone posted to other obvious places like Volumnio?

    43. Flatmax Studios 6-time creator on

      Hey hwanin21,

      Nice idea ! Actually I have looked into OTG using the Pi in device mode. It has been reported possible to set the Pi into device mode.

      We plan to put the VHDL on the chips to make it simpler to install and ensure it works reliably.

      Later we will do a latency test. At this point I expect sub 2ms with an unloaded CPU... stay tuned !

    44. Missing avatar

      hwanin21 on

      Great work!

      Have you investigated the use of the USB OTG as an audio gadget device for the raspberry pi? This could be the cheapest usb multichannel sound card out there.

      Do you have any plans for releasing the schematics and FPGA VHDL code? This board is something I have been looking for for a very long time.

      This doesn't matter that much, but do you have any latency numbers? I'm planning on using for a hexaphonic pickup for a guitar, and passing the audio over the network.

    45. Flatmax Studios 6-time creator on

      Hey Jeremy,

      Thanks for backing !
      Yes, each channel have have its own volume control so you can set the volumes as you like.
      You can potentially do anything you want, there are plenty of free GPIO lines for buttons or switches or whatever you fancy.

      We need more traffic to our campaign, can you suggest where we could promote this campaign ? Please share with your acquaintances.


    46. Missing avatar

      Jeremy wylie on

      Hello and thanks for this amazing board. I will be using this most likely with a different board then a ra!spberry but it also has the rasp pin out mount. I will most likely used in a vehicle scenario.

      In other answered questions. You said it can be faded forward/back by pinouts. And in a another area you said various channels could possibly controlled in volume. Making a full side to side front back control possible.if so this makes the board potential unstoppable.

      In your level control cross over diagram do I have this correct that there is four high channel and four low channels. Or are they all just free channels to be leveled to were user wants.

      Any chance for a screw down input output version in the future. I like the rca version i backed it. the break out version is not to my needs as it would have to be five pin not three and the plug version is not so vibration stable.

      Eagerly awaiting your response, and enjoy your summer, I'm getting sick of snow :)

    47. Flatmax Studios 6-time creator on

      Hey all,

      To get more stretch goals, we have to generate more interest !
      For that reason I have put together a little scoop for the media on the personal side. If you can get it out there, or know anyone who can do an article on this project, it would take us a long was for getting word out and more stretch goals happening !

      Here is a link to the personal scoop article article :

    48. Flatmax Studios 6-time creator on

      The pin outs are the I2C pins and the I2S bus pins. You can see these pins on the audio injector support forum post here :…

      Regarding chips, I will be uploading the drivers to the Raspberry Pi github Linux repo. after the campaign finishes. The codec is standard and has support for Linux. There is an FPGA onboard and there are a few pins used to signal the FPGA. Once I release the device tree sources I will point out those pins as well.

    49. Missing avatar

      Jeff T on

      @creator, thanks for the info, I had a further look and I think original Pi doesn't seem to have i2s so probbly not. Anyway, I also have other boards such as the PINE64 which has support for I2S, can you give us pin out of the octo if we wanted to use this on other devices that also have i2s?
      Could you also give us an idea of the chip being used in this project?

    50. Flatmax Studios 6-time creator on

      Hey Jeff,

      Unfortunately we don't have the original Pi and haven't tested it on that device.
      Check the following FAQ question for updates on what devices we have tested on.

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