Which IC/testboard do i need?

Hi there, My name is Toby Mulder a 26 year old student at the University of Utrecht in the Netherlands and I'm Just new on this forum!

I have a question about selecting the best solution for my idea.

For my Thesis I'm designing my own Eurorack Audio mixer/interface module (check pdf image for a visual prototype) and I'm looking for the best solution to do the following:

I want to create a Dj-style Audio mixer with atleast:

  • 8 Analog audio IN's (probably mono)
  • 2 Direct Outs (for Speakers)
  • USB connection for Digital Audio interfacing
  • 8 Digital Audio Outs via USB (the 8 ADC channels need to be converted to 8 separate DAC channels)
  • (optional) 1 Midi in
  • (optional) 1 Midi out

I want to build a working prototype before i start designing my own pcb, so i'm looking for the easiest and most compatible option out there.

I've been browsing around some evaluation board for different IC's but there are so many options that i wouldn't know what the best option is.

These are some of the boards/IC's i found that i think are a good option. 

https://www.analog.com/en/products/ad7768.html?doc=AD7768-7768-4.pdf#product-overview

https://www.analog.com/en/products/ad5592r.html

https://www.analog.com/en/ad7294-2

So if you have a suggestion for a better board/circuit or IC please let me know!

Looking forward to your replies,

Kind regards,

Toby

  • Hello Toby,

    Thanks for your interest in our products and keep up the studies. 

    All the devices you gave a link to are not audio converter products. The formats are different and the interfaces are not specifically designed for audio. They can be adapted but there are still limitations and it is the difficult road to travel. Look at this new eval board that recently came out. It does most of what you are looking for.

    https://www.analog.com/en/design-center/evaluation-hardware-and-software/evaluation-boards-kits/sharc-audio-module.html#eb-overview

    It also will give you a really good introduction to DSP programming. It is jumping into the deep end of the pool but that is why you are in school,... to be challenged. :)

    There is a codec on the board but it is only stereo. It will serve to give you stereo inputs and outputs for your speakers but you will need other codecs for more channels. 

    The AD1938 codec is probably what you should look at. It has four ADCs and 8 DACs. So you will need two of them. Now there is one problem in that the evaluation board for the codec is overly complicated and therefore expensive. The DSP group did have an audio expander for another SHARC eval board but I just went looking for it and did not find it on the web site. Go to the SHARC space on this forum and ask for help in interfacing 8 ADCs and at least 8 DAC audio channels into the SHARC Audio Module. The person who designed it should be able to offer suggestions. If you do not hear back then write a response back here on this thread and I will get an email. Then I can contact him directly. 

    Another option will be a board that will be released soon. It is a multichannel USB interface to our SigmaDSP eval boards. The unit will show up on the computer as a audio interface and then you can use TDM to transfer the data to and from one of our SigmaDSPs and then you can use our SigmaStudio graphical tools to program the devices. There are no converters so that is still an issue. 

    Then you can buy this eval board: https://www.analog.com/en/design-center/evaluation-hardware-and-software/evaluation-boards-kits/EVAL-ADAU1442.html#eb-overview

    It is one of our older parts but is still a powerful processor. This eval board is a little more expensive but it has 8 ADC inputs and 16 DAC outputs. It has two of the AD1938 codecs on the eval board. Then you will be able to interface to the USB interface I mentioned above and you will have everything except the Midi. 

    For that you could simply use a microcontroller I suppose. 

    So you have several options. Hopefully that USB interface will be out soon. 

    Dave T