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MDAC first listen (part V)

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quad2fan said:
I kind of hope it desn't sound as good as mdac after spending £600 on one only last month :rolleyes:

Hopefully there'll be some upgrades/tweaks for MDac users along the way that keep it up the top of the sound quality hierarchy. Wonder how much better Mpax will make it sound?

If your new budget DAC does sound as good there'll be an awful lot of Mdacs appearing on the classifieds over the coming months.....

Any idea on an eta for the new dac?

John
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Still atleast 3 months away - I'll be designing the PCB layout for the next couple of months...
 
quad2fan said:
At the risk of sounding like a broken record, any word on this John?
Click to expand...

Doms working in it:

DPLL setting have been added

Digital filter load fixed

I don't recall the other items - but work in progress.

We have discovered that there might be some "short term" issues with the MDAC update process - Dominik has one front panel that has an early version of microprocessor that has hardware bugs within that will result in the update "Bricking" the MDAC - the MDAC will be need to be return to the service center to have its processor replaced with a later processor without internal design bug.

The issue is a hardware design bug within the processor - and there little we can do except replace the early version processor when they are found.

We don't know the origins of the Dominik's front panel - it might be a very early development prototype. I've check the 6 units I have on hand, and non have the problematic MCU. We believe the UK will have the bulk of problematic units, as the first production shipments where sent to the UK.

We believe this issue will only effect very early units - but we really have no real idea, certainly later production units have the later MCU.

So - ATM, we are recommending to only update the software if you really need to as there is an unknown risk "Bricking" the MDAC. I'd guesstimate a 2- 5% chance...
 
JohnW said:
We believe this issue will only effect very early units - but we really have no real idea, certainly later production units have the later MCU.

So - ATM, we are recommending to only update the software if you really need to as there is an unknown risk "Bricking" the MDAC. I'd guesstimate a 2- 5% chance...
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Is it possible for the loader software to identify these buggy MCUs and say "take me to your dealer" rather than diving in and bricking an otherwise good unit?
 
JohnW said:
Doms working in it:

DPLL setting have been added

Digital filter load fixed

I don't recall the other items - but work in progress.

We have discovered that there might be some "short term" issues with the MDAC update process -
Click to expand...

John, will it not be possible to determine by serial number which units are affected? I had one of the first MDACs in the country and am eager to be able to update for things like filter selection, and ultimately to turn the screen off. But I don't want to brick my unit for those things and be without my MDAC for any length of time.
 
Plutox said:
Is it possible for the loader software to identify these buggy MCUs and say "take me to your dealer" rather than diving in and bricking an otherwise good unit?
Click to expand...

Could it also be determined by the serial numbers of the unit?
 
quad2fan said:
Could it also be determined by the serial numbers of the unit?
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Possibly, but only if the production line is run to ISO9000 kind-of standards. JW may tell us otherwise, but I suspect it's likely that there is little correlation* between unit serial numbers and the mask versions of various internal devices.

The best way, if indeed the buggy chips can be made to identify themselves with sufficient clarity, would be for the loader software to put up a warning, plus a refusal to attempt to re-program such devices.

*Audiolab might be in a position to say that no units above serial number x are affected, but units below x might be.
 
1. Sudden noise

Mdac connected to SBT via optical, suddenly started making noise (kind of white/pink type, to give you a general idea) while I was out and no music was playing. Wife turned off power amp after a few minutes. 4 hours later I listened through headphones and the noise was still there! Turned off the SBT - noise still there. Noise level dependent on mdac volume setting. Changing input and back again made the noise go away.

Has anyone seen this misbehavior? Not sure I feel safe connecting the mdac straight to my amp..

2. Headphone output jack

Having my headphones spiral cable caught on the edge of my table while moving them, a slight(!) pull on the cable was introduced and the headphone relay clicked off.. This only happens if I tug the cable to the left, in the direction of the display. Not right, up or down.

Should I consider this a hardware issue or is this somehow by design?

Thanks
 
Plutox said:
Is it possible for the loader software to identify these buggy MCUs and say "take me to your dealer" rather than diving in and bricking an otherwise good unit?
Click to expand...

If we had known about the issue before we could have built a routine in the MCU bootloader to read the MCU Rev ID. But IF we had known about the issue - then we would have insured these IC's where never used in our units.

There's is no way our software can read the MCU Rev ID - Dominik is updating the production programming software to prevent programming of these IC in the first instance - which will insure all future product is free of these Rev MCU.

There is a slight chance that Dom;s front panel was an early prototype build using IC's from a "Spot Buy" - but we cannot be sure.
 
JohnW said:
Doms working in it:

DPLL setting have been added

Digital filter load fixed

I don't recall the other items - but work in progress.

We have discovered that there might be some "short term" issues with the MDAC update process - Dominik has one front panel that has an early version of microprocessor that has hardware bugs within that will result in the update "Bricking" the MDAC - the MDAC will be need to be return to the service center to have its processor replaced with a later processor without internal design bug.

The issue is a hardware design bug within the processor - and there little we can do except replace the early version processor when they are found.

We don't know the origins of the Dominik's front panel - it might be a very early development prototype. I've check the 6 units I have on hand, and non have the problematic MCU. We believe the UK will have the bulk of problematic units, as the first production shipments where sent to the UK.

We believe this issue will only effect very early units - but we really have no real idea, certainly later production units have the later MCU.

So - ATM, we are recommending to only update the software if you really need to as there is an unknown risk "Bricking" the MDAC. I'd guesstimate a 2- 5% chance...
Click to expand...

Hi John

Agree with Plutox suggestion, post #822.

Or, if you want to get a better idea of the number of units involved first, maybe you could make available a download which just checks the M-DAC, without making any changes, and reports a message or code to determine if it needs upgraded hardware or not.

Once you know the numbers you can decide the best way to provide a fix.

All imo.
 
Hi John.

Are there visual markings on these 'awkward' front panel MCU's?
If so, I'd be happy to access the front panel and check mine to trial the newer software.
I'd always have the CDQ as a back-up.

Dave.
 
Nenox said:
1. Sudden noise

Mdac connected to SBT via optical, suddenly started making noise (kind of white/pink type, to give you a general idea) while I was out and no music was playing. Wife turned off power amp after a few minutes. 4 hours later I listened through headphones and the noise was still there! Turned off the SBT - noise still there. Noise level dependent on mdac volume setting. Changing input and back again made the noise go away.
Click to expand...

If the level of white noise is adjusted by the level control, then its being "Limited" in amplitude - thus indicates a digital miss-lock into the input data stream - confirm by changing inputs. I cannot say what the issue might have been as we have had no reports of a similar issue - and we now have well over 10K units in the field with users. I suggest to keep the D3E Mode enabled.

As the noise is being limited by the gain level - then you will not damage your power-amps etc.

If it was an odd misslock event - then the new software with DPLL settings may resolve the issue - but its so hard to comment based upon a single report out of many thousands of hours use (across many users).


Nenox said:
2. Headphone output jack

Having my headphones spiral cable caught on the edge of my table while moving them, a slight(!) pull on the cable was introduced and the headphone relay clicked off.. This only happens if I tug the cable to the left, in the direction of the display. Not right, up or down.

Should I consider this a hardware issue or is this somehow by design?

Thanks
Click to expand...

If the unit works reliably without external force on the headphone jack, then then I don't see the issue.

The headphone jack has a "Jack detect switch" which detects the jack inserted - if the jack is not FULLY seated home the the MDAC will not enable the headphones - this is the relay you hear clicking. Unless the MDAC is overtly sensitive the position of the jack - then this does not sound like an issue.
 
Wilky said:
Hi John.

Are there visual markings on these 'awkward' front panel MCU's?
If so, I'd be happy to access the front panel and check mine to trial the newer software.
I'd always have the CDQ as a back-up.

Dave.
Click to expand...

Hi Dave,

I've not knowingly seen an "early version" MCU myself, but I'd already asked Dominik and he says the Part ID printing is very different - Logo etc, I'll ask Dominik to try and photograph the differences.
 
finesensations said:
Hi John

Agree with Plutox suggestion, post #822.

Or, if you want to get a better idea of the number of units involved first, maybe you could make available a download which just checks the M-DAC, without making any changes, and reports a message or code to determine if it needs upgraded hardware or not.

Once you know the numbers you can decide the best way to provide a fix.

All imo.
Click to expand...

You give IAG way too much credit - but to be fair, nobody was aware of the differences of MCU versions until we started developing the update software.

The MCU manufacturer was not forthcoming in the first instance and buried this rather important information within many pages of Errata information - which required much investigation and head scratching to identify the issue.
 
Wilky said:
Nice one -I might just have a look and take a shot of mine.
Click to expand...

Wilky,

PM your Email address (as long as its not Google as its an EXE file) and I send you the current update build - if you brick your unit I'll just send you a whole new front panel buy express post...
 
Wilky, did you have a "day of release" unit in the UK? If so we can compare serial numbers as well. If not, I am okay to test this for John also if he can send a replacement front panel that quickly.
 
jonstatt said:
Wilky, did you have a "day of release" unit in the UK? If so we can compare serial numbers as well. If not, I am okay to test this for John also if he can send a replacement front panel that quickly.
Click to expand...

Hi Guys,

Little Point, serial numbers will say very little - IAG production is too random... and I'm sure they where scrabbling around component sourcing for the first batches until "official" vendor channels come online... They still cannot keep up with production demand even today.

John
 
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