MDAC First Listen (part 00100011)

[JohnW]

I thought that was answered by John's comment that, when first released the fpga won't do anything.

So I've understood that stuff like noise shaping will come later

Indeed correct, the FPGA in the initial release firmware will just handle SPDIF decoding / encoding and signal routing etc. once I've debugged and completed the production of the units then we can start to build-up the FPGA and DSP feature set

The MDAC2 with its Dual ESS, Advanced Analogue stages, Clock and PSU design will already be a large step improvement over the original MDAC with more to be released from the design as we develop the DSP / FPGA features - like fine Wine the MDAC2 will Mature and improve with age in leaps and bounds

 

[LarsS]

Adam,
there will be a small fee to help cover the development costs - there might be 6 months to a year development involved.

Of course, I don't see any issue with this. This is the way it should be, us covering the cost of what we want to use/buy aso regardless of it being hardware or IP protected software.

 

[JohnW]

This is the way it should be, us covering the cost of what we want to use/buy so regardless of it being hardware or IP protected software.

When it comes to the FPGA its pretty much "hardware" that's described / configured by Firmware (Software)

DSP is easier to work with, but the "Hardware" based FPGA is more flexible and can be "custom designed" for specific tasks such as DSD processing and Modulators etc. You can design internally to any Data width etc. its just how you design the circuit via software that describes the FPGA's internal circuits

Without the Software (Firmware) the FPGA is just a few 100,000 unconnected logic blocks waiting to be dictated there function in life

 

[jadidih101]

When it comes to the FPGA its pretty much "hardware" that's described / configured by Firmware (Software)

DSP is easier to work with, but the "Hardware" based FPGA is more flexible and can be "custom designed" for specific tasks such as DSD processing and Modulators etc. You can design internally to any Data width etc. its just how you design the circuit via software that describes the FPGA's internal circuits

Without the Software (Firmware) the FPGA is just a few 100,000 unconnected logic blocks waiting to be dictated there function in life

John,

FPGA development, as a software project, would it be like an 'open source' project? How do you/Dominic envisage code control and such? Or am I just thinking too far ahead?

Hossein

 

[adamdea]

I thought that was answered by John's comment that, when first released the fpga won't do anything.

So I've understood that stuff like noise shaping will come later

Sorry I think I must have missed that post.

Adam,

I'll be happy when the MDAC2's up and running with the ESS in "Native Mode" - the FPGA based noise shaping will be released much later - for such major advance "Pay For" functional upgrade there will be a small fee to help cover the development costs - there might be 6 months to a year development involved.
.

I hadn't quite worked out which bits of performance tweaking relied on the FGPA, and which bits could be got out of tweaking the setting on the ESS chip yourself to wring the best performance out of it.

I understand the sense of the model of charging for development of tricky features. That said I hope that the facility of applying Room correction filters can be added without enormous delay or expense: I mean applying filters which can be calculated using other existing software like REW or dirac. I assume that this would not be particularly tricky as the FPGA would just have to apply the filter (not that I would have any idea how to do it myself) leaving the user free to use whatever method they preferred to generate the correction filter.

 

[JohnW]

Adam,

REW does not "generate" the filters it only measures the room response and then provides the correction profiles - its then up to the DSP within MDAC2 to provide EQ based on this Profile. This is not too hard, but will still 2- 3 months work. Its relatively easy to get something going in a Beta release but it then takes time to fully debug and add the full "Complexity".

The DSP is very convenient feature and will handle the control of the Advanced clock and EQ / RC etc. - but the real funky features (ASRC, Advanced digital filters, Modulators) will be based upon the FPGA - and this will take longer to start to build up as effectively we are designing complex logic circuit blocks, not just maths and programming as is the case with the DSP.

The DSP and the FPGA are two different beasts - each have there place on the MDAC2 platform

 

[JohnW]

John,

FPGA development, as a software project, would it be like an 'open source' project? How do you/Dominic envisage code control and such? Or am I just thinking too far ahead?

Hussein

Hussein,

Each MDAC2 will have 3 unique 256bit Encryption keys based upon challenge and respond (MCU, FPGA and DSP) - we will maintain a database with each units "advanced feature set" - this allows us to freely release the software / firmware while allowing us to manage the "paid for" upgrades.

We have to encrypt the FPGA "firmware" to prevent third party's copying our IP...

The priority at this moment is to release the MDAC2 with its "Basic" functionality - and build upon this, the more advanced features will be atleast 6 Months to a year from production release of the PCB's - just due to the fact they require significant development time - its "easy" to design modulators - but an art to optimise there sonic performance

In its "basic" initial form the MDAC2 will be stunning - its what comes later in the year that will widen the gap from all others The ESS DAC IC in its native mode has its design limitations, we will go beyond these with the FPGA firmware.

That's the beauty of the MDAC2, its a platform that will just continue to improve, all you will do is install the new firmware via a software download - then you have a "New" design Like having a new product every few months

 

[Mikas]

That's a big "if", what if 2 dots aren't enough for a precise wave? And, if you increased the sampling frequency to infinity, wouldn't that be analog? Given that analog must in principle be better than digital if both were perfectly executed (because you get everything) doesn't increasing the frequency just take you nearer to the theoretical ideal?
I will follow those links BTW.

Did you followed the links already?


Michael

 

[Jeroengrt]

Last month i compared the audiolab mdac against a chord Hugo dac and a linn klimax renew ds...the mdac did it very good...the Hugo cost twice as much as the mdac, but in my opinion not twice as good. The linn was in another league....i am very curious what the mdac2 will do...when i have the mdac2 i will compare again....hopefully it arrives soon......mdac2 will probably arrive 2015 end of Q1?

 

[JohnW]

Last month i compared the audiolab mdac against a chord Hugo dac and a linn klimax renew ds...the mdac did it very good...the Hugo cost twice as much as the mdac, but in my opinion not twice as good. The linn was in another league....i am very curious what the mdac2 will do...when i have the mdac2 i will compare again....hopefully it arrives soon......mdac2 will probably arrive 2015 end of Q1?

Yes, by end of Q1 I'll start shipping the first PCB's

 

[Jeroengrt]

I can't wait

What is the best way to connect the mdac om a streamer? I use a sbtouch with edo mod, connected with a audioquest Carbon USB and a usb hub to support HD audio for sbtouch. During the comparing of the Hugo dac we connected the mdac om a Mac mini and that was also fine but i am curious how others connect the mdac.

 

[Rune]

I can't wait

What is the best way to connect the mdac om a streamer? I use a sbtouch with edo mod, connected with a audioquest Carbon USB and a usb hub to support HD audio for sbtouch. During the comparing of the Hugo dac we connected the mdac om a Mac mini and that was also fine but i am curious how others connect the mdac.

If you are not playing anything with a sample rate over 96khz then stick with USB. if you want to play 192khz music then you have to use spdif.

 

[iansr]

If you are not playing anything with a sample rate over 96khz then stick with USB. if you want to play 192khz music then you have to use spdif.

No doubt this has been answered before but is that a USB limitation such that it will also be true for the MDAC2?

 

[JohnW]

Ian,

The MDAC implements a USB1.1 port while the MDAC2 will support USB 2.0 and we will try to push the sampling rate to over 1MHz.... it will support 768KHz etc.

 

[iansr]

That should be enough for a couple of years. . . . .

 

[JohnW]

Hi John, I don't have a salvaged unit, just my one here. If it's not too much trouble I would gladly ship it to you, this really would be a great help. If it's ok I'll email you. Thanks

Nick,

Your MDAC arrived today - I'll add the AV bypass within the next 24 to 48 hours, still battling the MDAC2 PCB layout which I really want to get it issued Yesterday (OK months ago)!

 

[Nick1881]

Hi John, that's great. Please prioritise Mdac2, I'm not back home till the 12th anyway and I could go without it a little longer if needed. Loving the updates on your latest developments, keep up the good work.

 

[JTC]

JohnW: meant to say, P75 was dispatched yesterday, so you could receive it as soon as this weekend or early next week...

 

[JohnW]

John,

That's great, Thank you - hopefully I'll have issued the MDAC2 PCB by then and I can spend sometime listening.

 

[fusion5]

I'm still undecided about the slave DACs..