York DSP devices

[eclipsevl]

Hello,

couple of times I posted my projects photos in different threads but I think it is time to create a separate thread.

I've been working on the York USB UAC2 interface and then started transitioning into DSP hardware and software. One project is a 4 channel D-Class amplifier for which I started development of the configuration software:

And while working on it, I thought, well, it turns out as quite good software that can be used for other user-friendly DSP projects.
Around same time I have started talking to various people about active speakers and what type of DSP is needed there. So for that purpose I am working on a DSP product line, starting with a small one: balanced 2 channel in, balanced 4 channel out and quite a powerful DSP processor: ADAU1466 or ADAU1450. Here is the picture

For now I only have short description: the module is designed for active speakers/enclosure with multichannel amplifiers, has wide power supply range (7-55V), protection from the phantom power on the audio inputs, in case of assembly with ADAU1466 - S/PDIF input and output (can be used for subwoofer, for example).

On the P1 header there is I2C for configuration from sigmastudio or my GUI software, 2 AUXADC pins of the DSP (for potentiometers, for example), 2 DSP GPIO pins (can be used for preset selection)

The modules just went to production and I expect them to arrive in couple of weeks.

I'll share the measurements and other details later in this thread. And would love to hear some feedback if this type of modules are in demand

 

[Koifarm]

Hello, I have your York together whit 4 es9039q2m dacs for active 2 x 4 channel. Dsp i do on the PC.
I like to have hardware dsp, but most systems do have limited dac’s. Which dacs have your board?.
And has it I2S output to connect my own dac’s? Most people who want to use a good dsp like to use their prefered dac.

 

[eclipsevl]

Hi Koifarm,

I like to have hardware dsp, but most systems do have limited dac’s. Which dacs have your board?.

On this one it is PCM5424. Not the best one in terms of performance but still very decent.
There is always a tradeoff between cost/size/performance, this module is in mid-segment, I would say.
But I have plans to build other flavors too.

And has it I2S output to connect my own dac’s? Most people who want to use a good dsp like to use their prefered dac.

Then perhaps this one would be more interesting for you:

It is DSP (ADAU1466) + DAC (AK4458) modules, I build these as prototypes but actually thinking to make is as one module with addition of a good ADC.

 

[Koifarm]

Yes that one is interesting. I like to use 192khz24bit for the 8 channels. When adding high quality adc I have the perfect interface for my media PC. The ADC for my recordplayer. 2x4 for my 4way DIY Dynaudio speakers. Using my own design T-rex amps.

https://www.audiosciencereview.com/...o-good-for-diyaudio.67448/page-4#post-2528148

 

[eclipsevl]

Yes that one is interesting. I like to use 192khz24bit for the 8 channels. When adding high quality adc I have the perfect interface for my media PC. The ADC for my recordplayer. 2x4 for my 4way DIY Dynaudio speakers. Using my own design T-rex amps.

Amazing results! Yes, your amp would need something like AK4458 indeed.
It will take time but I am going to build a DSP on it.

Meanwhile, the prototype has arrived and so far everything looks good I'll post the measurements later, had to order several components for the ADC filter after some tuning

 

[Koifarm]

For now I will use York Pico iso and 4 es9039q2m pcb's.
And use media PC for DSP.

Super regulators:
https://www.audiosciencereview.com/...er-low-noise-power-supply.68935/#post-2497947

 

[eclipsevl]

That is an expensive setup!

 

[Koifarm]

Dac boards only 35 euro a piece.

Total cost about 300euro with housing. Ad 200euro for media player mini PC. And you have an excellent 2 x 4 channel DSP.
Other options with same specs cost over 2000 euro.

The complete setup will ad a view cost, like 1500euro for the amplifiers.And 2500 euro for the speakers. But this is the result of 50 years DIY audio hobby.

 

[eclipsevl]

I found these DAC boards on Aliexpress for ~60 Euro.

 

[eclipsevl]

Did the 1kHz bypass measurement (direct signal routing from ADC to DAC), THD+N is around 0.0016%, THD ~0.0006%
At -1dB signal level SNR is 97-100dB.

Adjusted some components to get very low noise floor. ADC noise floor:

Turned out very nice Also tested with e3 TPA3255 amplifier module.
Very convinient that it has 12v output, can be used for input stage or DSP. But for some reason it is sold without connector soldered.

Even if I put ear directly to the tweeter, can't really hear difference with and without DSP at max gain.

 

[Koifarm]

Good results, very tempting.

Can we already buy the dsp?

 

[eclipsevl]

Yes, going to post on Tindie on the following week.
But since you are in The Netherlands, will be easier to go directly. Please send me a PM.

 

[Koifarm]

Please tell more about the DSP and the software.

Can you config also one channel in and 4 channel out?
And how does the computer interface with the dsp board?
Further at what platforms tun the software?
And can you use 192khz/24bit for every channel?

 

[eclipsevl]

Please tell more about the DSP and the software.

Well, there are two options with this DSP:
1. Create your custom ADAU project
2. Use York GUI tool with predefined filter, EQ and other controls.

The GUI tool is still in development, for now each input and output has 8 band EQ, gain/mute controls, outputs have also IIR and FIR filters.
I am attaching some screenshots and build of the tool for Windows. But it is built cross-platform, I also use it on MacOS.
(It is build for my 4 channel amplifier, but for DSP it is same interface)
There is .exe file in the zip package of the current build. It is still work in progress so please forgive me for some UI issues

Can you config also one channel in and 4 channel out?

Yes, there is routing matrix:

The 2x4 DSP would have 2 analog + 2 S/PDIF inputs.

And how does the computer interface with the dsp board?

Now I use York nano board as USB-I2C interface but I'll make another interface board that would be cheaper, I would just include it with the DSP (50 cent mcu + small pcb).
I'll include Toslink RX/TX on that board too.

Further at what platforms tun the software?

Linux, MacOS, Linux

And can you use 192khz/24bit for every channel?

The on board ADC and DAC can work at 192kHz, although now I use 96kHz.
But it is possible, yes. S/PDIF input also supports up to 192kHz.

 

[Koifarm]

How is the PC software connected to the York DSP?
What interface do you use?

I like what I see.

Will it be possible in the future to get USB in for 8channel audio and programming the DSP?

 

[eclipsevl]

How is the PC software connected to the York DSP?

Currently I use York Nano as the USB interface, Pico also can be used.
For example, on this board:

York is used to stream USB audio to DSP, and to control the DSP via I2C - so everything is done with one USB cable.
It looks like such board fits better into your system: 4 external DACs can be connected to it. But it would require buffers to distribute signals across 4 boards.

Will it be possible in the future to get USB in for 8channel audio and programming the DSP?

Yes, I have plans to make such device (integrated DSP+DAC+interface)

What I have now:
1. DSP Prototype board with York Nano USB interface + ADAU1466 (the photo above), provides digital outputs for external DAC connection
2. 2x4 DSP module (the black PCB module) with analog inputs and outputs. To control this one I also use York USB interface and can stream digital audio as well but only 2 channels (via S/PDIF)

 

[Koifarm]

Thank you, all clear.

I know that a view people would like that USB in + DSP+ 8 channel I2S out + Software solution. You can choose your own DAC.
Adding a 2 channel ADC is also nice but it should also be high spec and it can be added separate later when needed.

 

[john61ct]

Hard to beat miniDSP PocketADC, plus flexibility of a modular turnkey gizmo can be repurposed later...

 

[Koifarm]

PocketADC has medior specs but good enough for phono inputstage. But needs extra interface to get USB out for PC.

@eclipsevl,
A highend dsp should have better then -125db distortion even -120db THD+N. And minimal 192khz/24bit data a channel.

Minidsp does not have that. But using your york and DSP and using very good dacs it is possible. This kind of DSP can fit my amps very well.

 

[john61ct]

I thought we were just talking about ADC / USB input to DSP.

It is very rare for any DSP modules to output USB, except for full computers like Wiim Ultra.

I cannot think of a use case for a DSP device to go INTO a PC, might as well have the PC dovtge convolving?

And IMO the SNR/THD specs are fine, overkill is not audible.

PocketADC has medior specs but good enough for phono inputstage. But needs extra interface to get USB out for PC.

A highend dsp should have better then -125db distortion even -120db THD+N. And minimal 192khz/24bit data a channel.
Minidsp does not have that. But using your york and DSP and using very good dacs it is possible. This kind of DSP can fit my amps very well.