Sigma ADAU1701 Review (DSP Board)

[kipman725]

As others have picked up, this is a board from @3eaudio : http://www.3e-audio.com/dsp/adau1701-2in4out/

I have a toslink/spdif to I2S board that I was going to replace the bluetooth module with. I didn't have time to test that before it went to @amirm for testing.

The board can also be powered by USB.

That won't work be because there is no asrc in the dsp so all clocks have to be common with the spdif. If you supply the dsp clock from the spdif it works but then that clock required power up before the dsp and is sample rate dependent. Anyway I tried this and you can read about my issues here: https://www.diyaudio.com/forums/dig...utpus-3e-audio-adau1701-dsp-aliexpress-6.html

If you could find a slave spdif device it would work (assuming sample rate match) but I am not aware of any that operate in slave mode.

 

[kipman725]

I hope SMSL, Topping, Loxjie, Schiit take notice of this!

The usual 2-channel DACs are almost a commodity. USB/SPDIF/Toslink, remote and optional XLR, Headphone amp ob Bluetooth. Performance is flawless, so why pay more than the cheapest one with SINAD over 100dB?

Meanwhile I need a high performance DAC that can handle stereo monitors +2...4 subwoofers using MSO. And then suddenly the only option left is miniDSP. I like miniDSP, but unless you pay a LOT more than a good stereo DAC for a miniDSP SHD then miniDSP is quite poor on the DAC quality side. So I dream about more alternatives to miniDSP 2x4 HD that have SINAD at least 100dB. XLR connections are a big bonus and the 3-band Equalizer is AWSOME!!! (see Shiit Loki and JDS Labs Subjective3 for examples, but all digital DAC version would be even better and cheaper).

Look into pro loudspeaker management systems: QSC, Symetrix etc.

 

[SDX-LV]

Look into pro loudspeaker management systems: QSC, Symetrix etc.

Well, but what do we know about their audio quality? There is pro stuff like https://dbxpro.com/en/product_families/driverack but it might not even beat miniDSP in pure performance. If there is a review that proves otherwise or at least companies that know how to make good DACs start making DSP units, then there will be more hope

 

[kipman725]

At least for Symetrix its pretty good, radius NX has the following spec: Dynamic range> 117 dB,
A-weighted.THD + Noise< -97 dB (22.4 kHz BW, unweighted); 1 kHz, 0 dB gain +8 dBu output
https://www.symetrix.co/products/radius-nx/
So that puts SINAD for the DAC portion as 105dB. They also have hardware attenuators so can maintain good specs over a wide input and output range. DBX my perception is these are lower quality units (but I haven't seen there most recent devices). But yes would love to see measurments. I have a Symetrix 8x8 DSP and DIGIO but don't have a high performance interface so can't give any personally measured numbers.

 

[ace_xp2]

So given the adau1701, is this a rough equivalent of what we're likely to find in a non hd minidsp? At about half the price, and with the ability to go to six or eight outputs with relative ease and low cost, that's a comparative bargain.

 

[The Jniac]

Wow. Just, wow. With that feature set and an $18 price tag I was expecting to wince a little at the performance. This thing has no right to be this good.

 

[Asinus]

So given the adau1701, is this a rough equivalent of what we're likely to find in a non hd minidsp? At about half the price, and with the ability to go to six or eight outputs with relative ease and low cost, that's a comparative bargain.

It is definitely ADI's SigmaDSP architecture, but the non-HD miniDSP seem to be using 144x parts, while this 1701 seems memory and clock constrained and it also does not include HW ASRCs
SigmaDSP Audio Processors | Analog Devices

It should be more than enough for crossovers and/or PEQ but probably not enough for FIR room correction on 8 channels

 

[andreasmaaan]

It is definitely ADI's SigmaDSP architecture, but the non-HD miniDSP seem to be using 144x parts, while this 1701 seems memory and clock constrained and it also does not include HW ASRCs
SigmaDSP Audio Processors | Analog Devices

Actually no, the standard MiniDSP uses ADAU1701.

 

[Asinus]

Actually no, the standard MiniDSP uses ADAU1701.

wow, I was basing my assumptions on this picture
https://www.minidsp.com/images/stories/virtuemart/product/_mg_0549.jpg
It is the only one where the model is visible.
If the other non-HD are 1701 then the miniDSPs must have very good margins given the HW and the BoM of the development kits.

 

[mdsimon2]

wow, I was basing my assumptions on this picture
https://www.minidsp.com/images/stories/virtuemart/product/_mg_0549.jpg
It is the only one where the model is visible.
If the other non-HD are 1701 then the miniDSPs must have very good margins given the HW and the BoM of the development kits.

Pretty sure that picture is a nanodigi which uses the 1445.

Michael

 

[andreasmaaan]

wow, I was basing my assumptions on this picture
https://www.minidsp.com/images/stories/virtuemart/product/_mg_0549.jpg
It is the only one where the model is visible.
If the other non-HD are 1701 then the miniDSPs must have very good margins given the HW and the BoM of the development kits.

Yeh, the margins would be good. But for the extra price you get input and output buffers, filters, connectors, etc, and of course also MiniDSP's software platform. Would make no sense for a manufacturer to use MiniDSP, but for a home user, I can see the value. In particular, AD's native SigmaStudio software is not really workable for the average consumer (although it's actually more powerful and versatile than MiniDSP's plugins).

 

[dtn]

https://www.audiosciencereview.com/...-dapx002-tpa3250-tpa3255-dsp-amplifier.14315/

 

[Vuki]

Yeh, the margins would be good. But for the extra price you get input and output buffers, filters, connectors, etc, and of course also MiniDSP's software platform. Would make no sense for a manufacturer to use MiniDSP, but for a home user, I can see the value. In particular, AD's native SigmaStudio software is not really workable for the average consumer (although it's actually more powerful and versatile than MiniDSP's plugins).

No, you don't get buffers with nonHD. This board is better equiped than nonHD 2x4.

 

[mga2009]

Please correct me if I am wrong, but without knowing which scheme is loaded into the DSP it's very difficult use the review numbers for reference.

The ADC and DAC on the ADAU1701 are not top performers, but they are not horrible either, and their performance can be degraded if the loaded scheme is not correct for the test.

If the tone controls are working, then it's very likely it's not just a pass trough scheme, which I would assume is the correct way to test the DSP performance.

 

[somebodyelse]

Perhaps @MatthewS can confirm, but it's probably using the stock DSP program which 3E publish the project file for at the bottom of the product page. I've not looked at it yet as SigmaStudio doesn't want to play with my only Windows VM.

 

[amirm]

If the tone controls are working, then it's very likely it's not just a pass trough scheme, which I would assume is the correct way to test the DSP performance.

I am not testing DSP performance but rather ADC/DAC. Performance is limited by second harmonic:

It is highly unlikely that any DSP processing creates such. FYI I played with tone controls and difference in SINAD was minimal until it clipped.

 

[mga2009]

Perhaps @MatthewS can confirm, but it's probably using the stock DSP program which 3E publish the project file for at the bottom of the product page. I've not looked at it yet as SigmaStudio doesn't want to play with my only Windows VM.

The default Sigma Studio scheme for the 3e Audio DSP

I am not testing DSP performance but rather ADC/DAC. Performance is limited by second harmonic:

View attachment 110207

It is highly unlikely that any DSP processing creates such. FYI I played with tone controls and difference in SINAD was minimal until it clipped.

OK. But what if the Sigma Studio scheme hasta a 6+db gain on the analog input, wouldn't that affect the performance or clip it?

 

[MatthewS]

Perhaps @MatthewS can confirm, but it's probably using the stock DSP program which 3E publish the project file for at the bottom of the product page. I've not looked at it yet as SigmaStudio doesn't want to play with my only Windows VM.

Yes, it is the default provided by @3eaudio. I can possibly open the file later and review it--I have their DSP powered amp and the default project is pass-through out of the box.

 

[mga2009]

I think this is the scheme that comes as default in the 3e Audio DSP.

The PEQs are all bypassed. Compressor should not affect, correct?

 

[mga2009]

Just wanted to update the info, as the DSP can do 2Vrms input by changing the input resistor.

It would be great if 3E just added some jumpers to make the modification.