New Wondom ADAU1701 DSP Unit

[ClayR]

Performance is about what one might expect. Schmoo is just under 80dB, with the usual spurious garbage.

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Things become quite interesting at 40Hz, with a relatively loud 4KHz spur appearing. This can actually be heard accompanying loud kick drums if listening very carefully.

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I just entered those numbers into a THD calculator and came up with 3.5% at 40hz and 0.15% at 1000. A post here on ASR references a article that references a study that found distortion at bellow 120 hz is really hard to detect and most people could not detect it bellow 10%. For other frequencies it was around 3%. So most people will never hear that.

 

[kemmler3D]

Performance is about what one might expect. Schmoo is just under 80dB, with the usual spurious garbage.

View attachment 340352


Things become quite interesting at 40Hz, with a relatively loud 4KHz spur appearing. This can actually be heard accompanying loud kick drums if listening very carefully.

View attachment 340353

Pretty interesting distortion profile, seems like a boutique exciter / warmer plugin.


But yeah these are coming up as $7 for me, so that price really covers many sins. USB DAC/AMP with 40 bands of EQ for $7. Nuts...

 

[kemmler3D]

So most people will never hear that.

This distortion isn't at 120hz... it's at 4khz. Much more audible. Typical discussion of audibility of distortion looks at 2nd or 3rd harmonic which are typical of overdriven analog boxes or speakers, but this little device is coming up with much more interesting harmonics, so the usual rules of thumb don't necessarily apply.

 

[ClayR]

This distortion isn't at 120hz... it's at 4khz. Much more audible. Typical discussion of audibility of distortion looks at 2nd or 3rd harmonic which are typical of overdriven analog boxes or speakers, but this little device is coming up with much more interesting harmonics, so the usual rules of thumb don't necessarily app

The study was referring to the fundamental frequency. When the fundamental frequency is bellow 120 hz distortion becomes hard to detect mellow 10%. At a 40hz fundamental frequency THD is 3%. At 1000hz it has a very respectable THD of 0.15%. If the device is used for it's intended purpose, an active crossover for a 2.1 system, the main channel DAC's would never see anything bellow around 80hz. So they won't produce the higher THD. The subwoofer DAC probably would, but the sub's spl would be so low at those frequencies you wouldn't hear them.

 

[Weeb Labs]

The study was referring to the fundamental frequency. When the fundamental frequency is bellow 120 hz distortion becomes hard to detect mellow 10%. At a 40hz fundamental frequency THD is 3%. At 1000hz it has a very respectable THD of 0.15%. If the device is used for it's intended purpose, an active crossover for a 2.1 system, the main channel DAC's would never see anything bellow around 80hz. So they won't produce the higher THD. The subwoofer DAC probably would, but the sub's spl would be so low at those frequencies you wouldn't hear them.

The 4KHz spur does not disappear until about 350Hz, so this isn't quite the behavior that would be observed. There is a great deal of functionality crammed into the BP1048B2, so I expect we are seeing filtering issue here. I will be travelling abroad tomorrow, so will do some poking around with my scopes when I return.

In any case, I don't regard this as an issue that merits any real concern; especially at the price point. The 4KHz spur is completely inaudible when listening to almost anything other than a sine or kick drum solo track and the other harmonic content is inaudible under all practical circumstances. Subjectively, it "sounds" like any other non-broken DAC.

I'll be printing an enclosure shortly and taking one of these boards with me anywhere that my KSC75s go.

 

[ClayR]

USBi is not required. It is configured directly via USB (while also supporting simultaneous USB audio), using ACPWorkbench.

Can you change settings on the fly the way you can with the Wondom Android app? Not sure if the app works with our little boxes though. it's not spacifically on there list. But they seem to say it works with there 1707 devices. I would have to buy a specific programmer that has bluetooth to try the app.

 

[Weeb Labs]

Can you change settings on the fly the way you can with the Wondom Android app? Not sure if the app works with our little boxes though. it's not spacifically on there list. But they seem to say it works with there 1707 devices. I would have to buy a specific programmer that has bluetooth to try the app.

Adjustments do take effect in real time but must be saved in order to persist through power cycles.

 

[ClayR]

Greetings,

While plumbing the depths of AliExpress as one tends to do in the middle of the night, I encountered a new product manufactured by WONDOM. It is effectively just an ADAU1701 in a convenient enclosure with all of the analog IO exposed, along with potentiometers and switches on the front panel. An additional potentiometer is included on the rear panel. All controls are labelled with the name of their GPIO pin, which should simplify identification in Sigma Studio.

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The unit is powered via USB-C and a USBi (for Sigma Studio configuration) is handled by a JST connector which matches that of WONDOM's existing ICP board. Incidentally, I would recommend purchasing the Tinysine USBi rather than WONDOM's ICP, as it is far more stable and robust.

The price is €38 (add €20 if you need a USBi interface), which I believe to be excellent value for money and I will likely be ordering one (or two).

I have confirmed my unit is defective. The point on the board labeled as 5 volts actually only has 2.8 volts. I get a full 5v at the usb port, so my usb charger is puuting out correctly. I contacted Wondom and got an after hours autoresponce saying they wil reply Monday. Has anybody had experiance with Wondom responce to problems, or Aliexpress responce should Wondom not respond appropriatly? I'm concerned that I recieved it on 12/9, but I would think a defective unit would be replaced for at a year or for an absolute minimum of 90 days.

 

[Westsounds]

Still, very interesting. This is absolutely the sort of thing that SHOULD be more common! I admit I was flabbergasted when I realized that MiniDSP was about the only game in town and charged hundreds to get very basic DSP features into your signal chain.

Yeah they were at one time I think the only game in town as you say. There seem to be more creeping on the market all the time though, which is a very good thing!

I'm really interested in these low costs ones.

Here's another, if not quite as cheap.

OMNITRONIC SMARD-24RCA Digital DSP Controller

OMNITRONIC SMARD-24RCA Digital DSP Controller

equipsom.pt

 

[Weeb Labs]

Things become quite interesting at 40Hz, with a relatively loud 4KHz spur appearing. This can actually be heard accompanying loud kick drums if listening very carefully.

View attachment 340353

Somebody asked me about this issue via my Discord server, so I thought it would be best to offer an update here. The 4KHz spurious tone is fully suppressed by increasing the size of the DVDD decoupling capacitor.

 

[dafreaking]

Somebody asked me about this issue via my Discord server, so I thought it would be best to offer an update here. The 4KHz spurious tone is fully suppressed by increasing the size of the DVDD decoupling capacitor.

Yes that was me. Hoping you can make a video on this board soon. I should hopefully get mine next week

 

[zeluxao]

Hi everyone. I'm looking for a cheap way to add hpf and some peq solution to my system. I'm electronically dumb and no soldering here too. I'd need a simple plug and play solution with some tinkering available through software or easy appliable. Would the initial wondom box be suitable? or can one the se boards be used just connecting some cables and achieving a similar (or better) end result?
Thank you

 

[Weeb Labs]

Hi everyone. I'm looking for a cheap way to add hpf and some peq solution to my system. I'm electronically dumb and no soldering here too. I'd need a simple plug and play solution with some tinkering available through software or easy appliable. Would the initial wondom box be suitable? or can one the se boards be used just connecting some cables and achieving a similar (or better) end result?
Thank you

Either the original unit or the Nvarcher boards would be perfectky adequate for this purpose. Do bear in mind that only the Wondom unit offers per-channel PEQ; the latter applies the same filters to both channels.

Speaking of Nvarcher, these boards are now down to €8.63! Time for me to order another batch.

 

[KTOnexus]

Entweder die ursprüngliche Einheit oder die Nvarcher-Boards wären für diesen Zweck perfekt geeignet. Denken Sie daran, dass nur die Wondom-Einheit PEQ pro Kanal anbietet; letztere wendet die gleichen Filter auf beide Kanäle an.

Apropos Nvarcher, diese Bretter sind jetzt auf 8,63 € gesunken! Zeit für mich, eine weitere Charge zu bestellen.

Wondom tpa3255 and dsp but can not connect

 

[zeluxao]

Either the original unit or the Nvarcher boards would be perfectky adequate for this purpose. Do bear in mind that only the Wondom unit offers per-channel PEQ; the latter applies the same filters to both channels.

Speaking of Nvarcher, these boards are now down to €8.63! Time for me to order another batch.

Thanks.