MDAC First Listen (part 00110001)

[adamdea]

I suspect the jitter is higher as the design is not a "True" Async USB design - by that I mean the DAC's Master clock is not used to synchronise the USB interface. You can see the x3 crystals on the XMOS board used to clock the USB port, while the DAC's Master clock is hidden below - this is not beneficial to performance.

On our little XMOS DAC PCB there are two DAC Master Clocks (the silver Cans near the test terminal marked "MCK", one for 44.1KHz based sampling rates and the second for 32KHz & 48KHz based sampling rates - these are then used as the reference clock for the ASync USB Data Buffer / flow control, this is TRUE ASync USB DAC operation.

https://dl.dropboxusercontent.com/u/86116171/XMOS DAC.png

That makes sense, John. So in adapting the board to take dsd input they have actually downgraded the overall design.
I think the jitter is higher for spdif too, though. Have they done something similar with the S/PDiF receiver too?

 

[Bob L]

I still prefer the small form so where does the Superior MDac fit in with the Lite/FDac and will there be an option to opt for the Superior MDac instead of FDac (L2 I think it was) ?

I don't think there has ever been any suggestion that Superior and FDAC are alternatives/options. The Superior is a by-product of the FDAC development to which we have all subscribed , and if we want it there is a possibility to have current MDACs upgraded in this way , but we pay the extra cost which John has indicated for this.

Afterwards, when your FDAC/FDACLite arrives, it should be fairly easy to sell off your Superior, especially given the distinctly negative comments on the German site quoted above about the Audiolab "MDAC+" vs. the unmodified MDAC.

 

[adamdea]

especially given the distinctly negative comments on the German site quoted above about the Audiolab "MDAC+" vs. the unmodified MDAC.

I might have misunderstood the google translation, but is that by any chance a website which sells upgrade kits?

 

[fusion5]

Yes, hoerwege.de does sell upgrade kits.

 

[adamdea]

Yes, hoerwege.de does sell upgrade kits.

<sigh>

 

[StephenB]

wibble wibble wibble

<sigh>

on the basis John has to read through all this before he gets round to his intention to give us all an update, any chance you can all put a sock in it temporarily ?

or perhaps the time has come to set up a thread purely for project updates for those of us who are less interested in discussing ad infinitum the most tedious of subjects that can be linked as loosely as possible to MDAC [which in all honesty has no bearing on the FDAC product anymore]

too much time on my hands preparing for a house move

 

[adamdea]

wibble wibble wibble

<sigh>

on the basis John has to read through all this before he gets round to his intention to give us all an update, any chance you can all put a sock in it temporarily ?

or perhaps the time has come to set up a thread purely for project updates for those of us who are less interested in discussing ad infinitum the most tedious of subjects that can be linked as loosely as possible to MDAC [which in all honesty has no bearing on the FDAC product anymore]

too much time on my hands preparing for a house move

It probably would be a good idea if project updates were separated out, although not for the reason you give. Up to now the rambling thread and the project itself have been linked, paralleled and mutually inspired in all sorts of ways. Probably won't change.

 

[Jason_PFM]

wibble wibble wibble

<sigh>

on the basis John has to read through all this before he gets round to his intention to give us all an update, any chance you can all put a sock in it temporarily ?

or perhaps the time has come to set up a thread purely for project updates for those of us who are less interested in discussing ad infinitum the most tedious of subjects that can be linked as loosely as possible to MDAC [which in all honesty has no bearing on the FDAC product anymore]

too much time on my hands preparing for a house move

This is what it may feel like ;-)
http://lifehacker.com/5952456/how-to-master-the-art-of-looking-busy

 

[JohnW]

wibble wibble wibble

<sigh>

on the basis John has to read through all this before he gets round to his intention to give us all an update.

Just working on testing the clock circuits for the XMOS Software Development board, will update soon...

 

[LarsS]

Seems as below was lost amongst all recent posts.

@JohnW,

sold my MDAC when you decided to abandon the upgrade of the MDAC in favour of FDAC, which was fine, in retrospect (see Superiour MDAC) I feel a bit cheated.

Anyway, there's a couple of questions from me (see previous post from me) and a new one below.

I know you have/had a stash of MDAC's awaiting repair as slave MDAC's, any plans to have them available as Superiour MDAC's for us?

/Lars

 

[JohnW]

The salvaged MDAC's are the property of there respective owners until they are "traded in" for the FDAC FWC so I'm not able to sell these on at the moment.

I can still source salvaged units from Audiolab...

 

[JohnW]

wibble wibble wibble

<sigh>

on the basis John has to read through all this before he gets round to his intention to give us all an update, any chance you can all put a sock in it temporarily ?

or perhaps the time has come to set up a thread purely for project updates for those of us who are less interested in discussing ad infinitum the most tedious of subjects that can be linked as loosely as possible to MDAC [which in all honesty has no bearing on the FDAC product anymore]

too much time on my hands preparing for a house move

With so many developments coming together ATM, I really rather just keep one thread that I can an eye on, I'm trying to avoid the many distractions of the internet

Recent developments:-\

The XMOS development board has arrived, I've ust built and tested the Clock circuit so Jarek can work on the rest:-

https://dl.dropboxusercontent.com/u/86116171/MiniDAC Clock Proto.JPG

Also, hopefully I'll complete the testing of the first superior PCB by tomorrow evening - with listening test to follow very soon

 

[ti33er]

Hi John/Lars

My 'black' Salvaged MDAC payment is intended to be converted into FDAC FWC penultimately, so there is at least one MDAC up for grabs on my part ;-)

Thanks

 

[Jeroengrt]

I have sold my mdac, and i signed and paid for the initial project. What kind of options are there? Is the fdac lite with new case still an option? Or do i have to buy a second hand mdac and pay 500gbp for the supreme option?

 

[Hawtin]

Hi John/Lars

My 'black' Salvaged MDAC payment is intended to be converted into FDAC FWC penultimately, so there is at least one MDAC up for grabs on my part ;-)

Thanks

Hi John / Boozyuzi

I also have paid for a salvaged MDAC and I am certainly going for FDAC FWC. So for what it is worth, if it is possible to forward my salvaged unit to someone in need then go for it. I also understand if all this is too much hassle at this point.


-H

 

[LarsS]

Hi John/Lars

My 'black' Salvaged MDAC payment is intended to be converted into FDAC FWC penultimately, so there is at least one MDAC up for grabs on my part ;-)

Thanks

Hi ti33er,

If JW decides to convert your "Salvaged MDAC" into a "Superiour MDAC" I'm more then willing to reimburse you for the Salvaged MDAC cost as well as taking the Superiour MDAC costs to JW.

/Lars

 

[ti33er]

Hi ti33er,

If JW decides to convert your "Salvaged MDAC" into a "Superiour MDAC" I'm more then willing to reimburse you for the Salvaged MDAC cost as well as taking the Superiour MDAC costs to JW.

/Lars

Absolutely. Thanks Lars

I had a Banking friend potentially interested but he has been put on 'Gardening Leave'...not a good time for Bankers :-(

 

[PhilCTTE]

I'm sure there will be a few up for grabs from those on the FDAC list. My fusion model for instance, as I only have one system in my house. In fact no system at the moment as my listening room as we speak is being knocked through.
There was one going for about £300 btw on avforums

 

[Elviz]

JohnW,

I'd like to know if I owe you development money? I have the m-dac fusion premium, and i paid £300 almost two years ago in advance (by mistake). I am going for FDAC FWC (level 3). Its impossible to keep track of these things.

br, Elviz

 

[mbaudis]

Hi ti33er,

If JW decides to convert your "Salvaged MDAC" into a "Superiour MDAC" I'm more then willing to reimburse you for the Salvaged MDAC cost as well as taking the Superiour MDAC costs to JW.

/Lars

I have currently 2 MDACs with John, bulging caps, waiting for fix/superior upgrade. I'm willing to give one of them to a thread member, w/ value of "used" MDAC covering (some of) the other's upgrade cost (i.e. you pay the whole thing to JW, and he splits - no idea if he would handle this, though ...).