Does anyone know if this USB power supply would be compatible (in the sense given towards the bottom of the webpage) with the MDAC, ie. if the MDAC USB chip is powered externally (compatible) or internally (incompatible)?
MDAC first listen (part IV)
- Thread starter adamlau
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The mdac doesn't need/use a usb power supply - it's irrelevant
It's not applicable to the M-dac or CDQ. Neither need or use a power supply.
The isolator is there to break the electrical connection between the usb and dac.
If that connection is causing no problems then you needn't buy one.
replied in other thread
the problem is that don't really know there are no problems until you try an isolator and find it has no effect (triple negative)
True enough. They are cheap enough to buy and try. Might as well have one just to know it's a clean cac free connection.
JohnW,
Slight problem here with my CDQ and USB input. As per page 15 of the user manual i can't get the display to read 16bit/44.1k even though i have ASIO running with Foobar. Could you please advise as to what i might be doing wrong and what i vould to ensure the display read correctly?
Slight problem here with my CDQ and USB input. As per page 15 of the user manual i can't get the display to read 16bit/44.1k even though i have ASIO running with Foobar. Could you please advise as to what i might be doing wrong and what i vould to ensure the display read correctly?
John_73
pfm Member
Question to those that downloaded the recent beta firmware update for MDAC which was posted in this thread: Did it include the bug-fix for the incorrect filters being selected when using any input other than USB (which does display the correct filter being used)? Much as I like my MDAC I do consider this a rather huge bug (wonder how many out there actually prefer a filter which is actually different to the one they think they're listening to?! Might have affected some product reviews too...). Looking forward to the official bug-fix release.
- John
- John
Does it always read 48kHz? If so, you might have ASIO4ALL's resampling enabled - you will need to select ASIO4ALL's advanced options to get to this to deselect it.
What does the status bar (bottom of Foobar screen) say about the file being played? The sampling rate will match the CDQ status if all is well.
It can't be that important a bug seeing as nobody noticed any inconsistency issue with the filters till JW himself owned up
JohnW
pfm member
Hi John,
The Beta test software just opened up the DPLL BW on Optical input 2.
Dominik has the Full up-loader completed yesterday (that uploads both Main board and front panel processors) - he now is working on actually updating the software - so I hope the "Audiolab" build will be ready towards the end of this week.
The Auidolab build will include:-
1. Add DPLL BW settings for each input
2. Fix the Digital filter load issue (on SPDIF inputs).
3. Try and reduce locking times (for units that Mute the SPDIF between tracks etc).
Additional features will be incorporated into the "Lakewest" build.
John
bigmarcelo
pfm Member
This is excellent news John - thank you.
I'm hoping the DPLL BW settings will fix the dropt/lock issue I have with my Marantz NA7004 and 24/96 files (Coax 1)
Regards,
Marcelo
My MDAC is in the classified if anyone is looking to save £50 on a new black one.
http://www.pinkfishmedia.net/forum/showthread.php?t=115151
Alan
http://www.pinkfishmedia.net/forum/showthread.php?t=115151
Alan
John_73
pfm Member
That's great news John - look forward to downloading that once it's ready
For those with the first second or so of music cutting off due to the lock times, I found if I press play on the CD player, then immediately press pause, then play again letting the rest of the CD play normally, this works as a temporary work-around.
- John
I will try if I have your same issue as soon as I have time....
finesensations
pfm Member
Hi Arthur
What's confusing me is that you, ChrisPa and others are 'reporting' improvements in SQ when using a USB Isolator even when there is no 'problem' to fix.
You say 'The isolator is there to break the electrical connection between the USB and DAC' but according to Device Manager (WinXPsp2) the USB Hub I'm using exclusively for my M-DAC shows Power Required 0mA.
So, if no current is flowing, why would an Isolator be needed to break the electrical connection and how would this improve SQ?
Maybe worth checking your Device Manager (or equivalent) to see for yourself.
JohnW
pfm member
The Windows report's of 0mA refers to the USB Power requirements, MDAC does not require power from the USB port (So any efforts to provide clean power are totally pointless).
However there is a Ground connection between the PC/MDAC due to the USB signaling (Data Link). A USB isolator breaks this Ground loop (atleast at lower frequencies - RF will still leak across the isolation barrier).
John
JohnW
pfm member
Hi John.
I know this is an anal question
But would two in line isolators reduce the HF any further. I'm quite happy to be obsessive with regards to a clean as possible signal to the MDAC and CDQ.
Cheers.
Never tried it, but in theory yes, cascading isolators would improve the RF isolation.
But first, Pls. let be buy shares in the USB isolator company...
The only concern would be any extra RF spurie as a result of the isolators secondary side power transfer (the isolators have small isolated switching supply's to power the secondary side logic). Cascading isolators increases the number of Swicthing supply's which maybe detrimental.
Try and lets us know your findings (and before I consider buying shares!!!),
John
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