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exaU2I - Multi-Channel Asynchronous USB to I2S Interface

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#782
regal said:
There are a lot of folks "into" the AD1862, AD1865, PCM56, PCM58, even PCM1702/1704. Good dac's really. But the I2S connection sans digital filter is always problematic. Wouldn't it be nice if the exa firmare or maybe even the driver software could be configurable for the DAC of choice. I mean this thing has 8 channels right? Why not for stereo split the I2S into L&R combatible format for these different DAC's. Just click the mouse to pick AD1865. It would be a huge advancement for all the NOS builders. Even if you aren't into NOS you could use the computer to upsample, which would allow a better analog filter. The potentital is there really, and with Hirez becoming more popular a 24/192 PCM1704 NOS DAC starts to make a lot of sense to even those not into NOS. Heck there are even reports of some new commercial NOS PCM1704 beating the PM2.

Just saying there is a potentital to really expand this. In a few years you can bet a lot of folks will be oversampling with their computer (custom PC digital filtering), this would be a step in that direction.
Click to expand...

This is a great idea right here! Using software to make the exa compatible with all these old dacs should be possible. It could be incorporated in the exa dashboard. I'm running the AD1865 at 192 kHz in NOS mode right now, and it sounds absolutely terrific!
 
#783
Javin5 said:
So here is one more question on the exaU2I.

Is there a way I can play via the exaU2i anything that plays on the PC, e.g. web radio? I suspect not, but I'm asking the experts here anyway to have it confirmed. Thanks for your answer.
Click to expand...

Hi Javin5,
You can play Internet radio with Foobar. You can also use a third party driver - Virtual Audio Cable to redirect the native Windows sound output to exaU2I. VAC supports up to 8 channels / 192 kHz. You can find the setup guide here: exaU2I DB - Installation and Configuration of Native Windows and ASIO Drivers.
 
#784
Hi exa065
Now I'm listening 2 way VST straight FIR channel divider, with..
foobar2000(ASIO) - (Reaper + 2 VST_FIR) - exaU2I.
This solution is very simple. great. 🙂
(but there is performance overhead for Reaper)

Screenshot: shows very sharp Low pass filter.
Source code: small enough, this is VST source code which has VST interface, FIR coefficient generator, and CUDA FIR logic.
(requires VST SDK and CUDA SDK to build)

The reason why I am sticking with Straight FIR (not FFT FIR) is, FFT FIR requires Hunning Window processing on input signal.
 

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#789
exa065 said:
Hello KOON3876,
Can you tell us more about your system? What kind of speakers do you use? Have you tried any high-resolution multichannel sources?
Click to expand...

Hi Now I am using LINN Komponent 104.
(before I had also LINN Akurate 212)
This is 3Way speaker, Crossover can be bypassed.

Stereo Source, foobar etc -> Reaper+straight FIR channel divider -> exaU2I -> this amplifier (up to 4Way) -> Stereo speaker, multi-amplifier configuration.

So I am using exaU2I not for multichannel, but for Multi-way stereo configuration.
 

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#791
Painkiller said:
That's an interresting configuration. Never seen an amp like that before. Is it a diy project, or is it store bought?
Click to expand...
There is no amp in that picture. That is the input connector panel for a 3-way speaker. Linn has been making products for thirty years, sold in audiophile shops. They're quite keen on biamping and triamping speakers, so it is not too hard to disable or segregate the crossover to access individual speaker drivers within the same cabinet.

Linn - Music Systems - Komponent

I would be very interested to learn what filters, and slopes are most effective for the Komponent 104. Does the owner's manual mention frequencies, or do they consider it all proprietary?
 
#793
Painkiller said:
I was of course referring to the 8 channel digital amp in this post: Post #786

Interresting piece of gear
Click to expand...

Hi the original thread
http://www.diyaudio.com/forums/class-d/91148-full-digital-crossover-multi-amplifier-integrated.html

page
https://sites.google.com/site/koonaudioprojects/tas5518-full-digital

TAS5518 only: can do IIR 24db/Oct crossover.
Stereo Source -> TAS5518(4Way crossover) -> up to 4 Way Speaker

Now, with PC:
PC = Source, and FIR crossover
exaU2I = ASIO to I8S output
TAS5518 = accepts I8S, do nothing but amplify

I do not recommend DIY this amplifier. I spend some thousands and months.
If you want multi-way full digital Amplifier, try TAS5706.
 
#794
rsdio said:
I would be very interested to learn what filters, and slopes are most effective for the Komponent 104. Does the owner's manual mention frequencies, or do they consider it all proprietary?
Click to expand...

Owner's manual does not show the filter detail, but crossover frequency = 1kHz and 3.5kHz.
I used IIR 24dB/Oct filter before, Now using FIR (200dB/Oct or so).
 
#795
jitter

exa065 said:
Hi Everyone,

I’ve been working on a new design for 8-channel Asynchronous USB to I2S interface. It started as a fun project and eventually became more involving than just a hobby. A couple of friends joined in and helped with the development of bit-perfect ASIO driver covering all sampling rates up to 352.8 kHz. At the present time I am testing it with a ES9018 DAC.

Here are the details:
• Sampling frequencies (kHz): 44.1, 48, 88.2, 96, 176.4, 192, 352.8
• Resolution (bits): 16, 24, 32
• 8, 4 or 2 channels for sampling rates up to 192 kHz
• 4 or 2 channels for 352.8 kHz
• Galvanic isolation between the USB ground and the I2S outputs.
• Two quartz oscillators for the 44.1 kHz and 48 kHz sampling rate groups
• FPGA implementation
• 256 kB FIFO buffer to support asynchronous operation
• Two analogue voltage regulators with filters
• Sample rate LED indicators
• USB power LED indicator
• Buffer level LED indicator
• Four I2S data outputs (8 channels) powered by the DAC power supply (3.3V or 5V)
• USB 2.0 interface, Mini USB connector
• Proprietary bit-perfect ASIO driver completely independent from the Windows sound system; No software volume control or mixing.
• ASIO driver implements automatic sampling rate switching; no re-sampling
• Works on Windows XP, Windows Vista and Windows 7.
• Tested with Foobar and J.River Media Center
• Project homepage – www.exadevices.com > Home

I am about to make the USB to I2S interface commercially available as a kit.

Any feedback is highly appreciated.
Click to expand...

Hi!!!

could i know how much is jitter?
Have you measured it (with audio precision?) ?

regards

gaetano
 
#797
#800
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