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Hi-end DSP based multi-channel integrated Preamp/Crossover/DAC project

Why is higher than 96khz needed?

This is a DSP that can do phase alterations. So high FS gives easy phase changing with high resolution.

With respect to sound speed. The sound move about 2mm a sample at 196k and 8mm a sample at 44.1 Hz.

There is of course other ways of delaying, but no easier ways.

And a highend DAC at under 192kHz is hard to get these days.

Remember that downsampling and/or noiseshaping is fully feasible with audioweaver. Then you can put the noise where you personally don't hear it.
 
@Tranquility Bass

This looks like a fantastic design, and while you're well beyond making any majors changes to the design, please don't laugh to much at the following questions, or suggestions.


-The primary problem with a good deal of the active crossover solutions comes down to integration with multichannel sources, and HDMI because DRM that only exists to make it a pita for people who pay for their media.

? Is it possible to use different usb - i2s that can provide digital signals for Front (L + R), and R (L + R)? As in, utilizing the existing digital sources, or are they all on a selector? B/c maybe i'm misinterpreting the "isolated". Where an HTPC can act as the source.

? - Will there be some sort of exposed control interface so that it can be controlled with say andruino , or beaglebone?

I only state this, because in the vast majority of audiophile implementations that I have visited... it's rare for them to have 7.1, and two properly setup front channel speakers can create an adequate virtual center, because if they can't... they can't image worth a damn, or have an incredibly narrow "sweet spot".

? - Can the optical/ coslink outputs be utilized with different settings? 1 - Can one digital output go to an external dac/ processor to handle any needed sub bass duties, and another can goto a headphone dac/amp routing the front channels or maybe another profile to use the dsp for some funky headphone functions (ambiophonics... etc.)?

? - Assuming that intended implementation might be to use after a home theater processor or source, does the dsp report back to the user the expected delay due to processing time, so that this can be handled and account upstream in some sort of multi channel source?

? - Elaborate on your implementation of HT -bypass? IE, idiot proof volume control?

Also, I like everyone else is hoping that this is closer to minidsp 10x10hd money than say deqX money. :)

Have a fantastic day.

HDMI implementation requires a huge upfront licensing fee as well as ongoing maintenance fees just to extract the I2S audio stream. Not really worth it for this application since this board's major use will be as a stereo preamp and/or active crossover for stereo speakers. Not sure but do any HT receivers provide the pre-outs over a HDMI connector ?

The HT bypass will now have it's own set of dedicated RCA connectors and will not be affected by the volume control so use this input at your own peril !! Does anyone need XLR inputs for HT bypass ?

There is both an optical and coax output but only can be driven from one SPDIF source. Headphone output will have it's own dedicated DAC board.

External control over the USB port will be possible. Not sure how you'd accomplish this with the Arduino.

cheers
 
Still waiting on news from EssTech regarding latest ES9018PRO ADC. :headbash:

PriceUSA screwed up an order for some 9018 DAC's and sent me someone elses parcel because I changed the order from the 9012 ADC which EssTech said they had in stock but didn't by the time I ordered it :(

Dealing with EssTech has been a nightmare. Moral of the story is do not design in parts which can't be delivered to you from the nominated distributor. :nownow:

In the meantime I'm building up some complete units for evaluation and testing to weed out any problems ;) You can follow this on my facebook page.

cheers
 
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So, let me remind you again, there are more reliable suppliers in the business.

Not to mention:
"AKM will announce the flagship “VERITA” DAC AK4497 at CES 2016. AKM will release the detail of product spec and demo using the reference design combines AKM’s newest SRC, (AK4137), to achieve the up-sampling from any input to, 768kHz/32-bit. The AK4497 provides the best sound quality and astonishing performance such as super-low distortion and highest SNR performance on product lineup."
 
So, let me remind you again, there are more reliable suppliers in the business.

Not to mention:
"AKM will announce the flagship “VERITA” DAC AK4497 at CES 2016. AKM will release the detail of product spec and demo using the reference design combines AKM’s newest SRC, (AK4137), to achieve the up-sampling from any input to, 768kHz/32-bit. The AK4497 provides the best sound quality and astonishing performance such as super-low distortion and highest SNR performance on product lineup."

The AKM parts haven't gone unnoticed and they are cheap and readily available from digikey which can also send outside the US. ;)

cheers