This is a review and detailed measurements of the Sigma ADAU1701-2In4Out DSP board from @3eaudio . It was kindly loaned to me by a local member. I think it costs $18 for the main board (?) The version I have has the tone control and USB interface options as well.
This is what the whole setup looks like:
I was pleasantly surprised to find balanced outputs on such a low cost solution. I used the tone control board to get access to analog inputs for testing. I did not want to install drivers and such (which seemed pretty messy from the documentation) so did not use the USB dongle. As such, I had to power it using my lab supply which I did with 12 volts (range is 7 to 12 volts).
Here is a closer shot of the main board:
The bluetooth board add-on seems quite messy but I assume this is supplied by someone else and not Sigma.
Sigma ADAU1701 Measurements
There is no way to defeat the tone controls that I could see. And unfortunately there is no center neutral position forcing me to spend quite a bit of time to get more or less flat frequency response:
Once there, I left them as is and ran the rest of the tests starting with our dashboard:
Anything higher than 1.1 volt would cause clipping even though datasheet states that is the max level. Unfortunately that limit means that we can't get our nominal 4 volts out, nor can you use a standard desktop DAC that outputs 2 volts as is. You need to lower the volume on it to avoid clipping.
Overall performance -- considering that is the combination of ADC and DAC -- is not bad for something like this. You are distortion limited. If you lower the output even more, it gets a bit better:
Dynamic range barely makes it past 16 bits:
Finally, a comparison against a commercial solution, the minidsp DDRC-88:
Definitely not in the same class.
Conclusions
I can see the appeal of this board: two channel input and four channels out makes for a nice crossover solution for active speaker design. Performance is good enough for DIY/hobby solution. The audio elitist in me wants something better
but you can decide for yourself. I am not going to pass judgement on it one way or the other.
------------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
This is what the whole setup looks like:
I was pleasantly surprised to find balanced outputs on such a low cost solution. I used the tone control board to get access to analog inputs for testing. I did not want to install drivers and such (which seemed pretty messy from the documentation) so did not use the USB dongle. As such, I had to power it using my lab supply which I did with 12 volts (range is 7 to 12 volts).
Here is a closer shot of the main board:
The bluetooth board add-on seems quite messy but I assume this is supplied by someone else and not Sigma.
Sigma ADAU1701 Measurements
There is no way to defeat the tone controls that I could see. And unfortunately there is no center neutral position forcing me to spend quite a bit of time to get more or less flat frequency response:
Once there, I left them as is and ran the rest of the tests starting with our dashboard:
Anything higher than 1.1 volt would cause clipping even though datasheet states that is the max level. Unfortunately that limit means that we can't get our nominal 4 volts out, nor can you use a standard desktop DAC that outputs 2 volts as is. You need to lower the volume on it to avoid clipping.
Overall performance -- considering that is the combination of ADC and DAC -- is not bad for something like this. You are distortion limited. If you lower the output even more, it gets a bit better:
Dynamic range barely makes it past 16 bits:
Finally, a comparison against a commercial solution, the minidsp DDRC-88:
Definitely not in the same class.
Conclusions
I can see the appeal of this board: two channel input and four channels out makes for a nice crossover solution for active speaker design. Performance is good enough for DIY/hobby solution. The audio elitist in me wants something better
but you can decide for yourself. I am not going to pass judgement on it one way or the other.------------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
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