advertisement


MDAC first listen (part III)

Status
Not open for further replies.
A quick update, I may have figured out the problem, it seems like the Audiolab drivers and the nVidia display drivers I was using weren't playing nice with each other. Seeing the issues were mainly with video and I wasn't terribly impressed with the current version of the nVidia drivers anyway I uninstalled the nVidia drivers and reinstalled the much older version I had previously been using. So far at least, this seems to have rectified the problem with loud clicks and squelches during video playback.

edit: And on a side note it seems somewhere in all this the songs locking up in foobar when using WASAPI seems to have righted itself as well. I got home today and realized the M-DAC had been going all day with foobar set to use WASAPI. I just tried the bit perfect test and it went off without a hitch.

edit2: Something to note, at the end of the bit perfect test it still showed as passing even though the track had ended. after I typed the above edit I went to listen to some music and the sound was staticy predominately out of the left ear. I shut restarted foobar without any affect. Shutting down the M-DAC for a minute fixed it though.
 
To be pedantic I understood the update software will be a java application not javascript
(but js does stand for javascript)

elnero
The mdac uses standard usb drivers - the ones included in the operating system
 
elnero
The mdac uses standard usb drivers - the ones included in the operating system
I don't think it does, when I first plugged it in the "installing device driver" notification came up and when using USB it shows up as "Audiolab M-DAC" in the sound settings.

edit: Hmmm, I just checked in the Audiolab M-DAC properties, under the Driver tab it says "Driver Provider: Microsoft". I swapped out the M-DAC with my Pico DAC which I know uses the standard USB driver and according to the driver version it's using the same driver. Now I'm confused, what the heck was the driver install and why does it show as the Audiolab M-DAC in the sound properties and why do the two DAC's react differently if they're using the same driver?
 
Every time you plug a new piece of hardware into a new usb slot the operating system realises it's never seen it there before and has to work out what to do with it. If it recognises the signature as matching one of the drivers it already has, it will use that. Each piece of hardware has a unique name whether it uses standard drivers or not. The device name and driver signature are independent pieces of information (there loads of others too). This decision and installation process is 'installing device driver' whether it's MS's driver or one from the manufacturer.

React differently?
Because they move data in a different way (synchronous vs asynchronous) and they buffer and handle the data internally in a different way, even though they use the same common driver
 
Every time you plug a new piece of hardware into a new usb slot the operating system realises it's never seen it there before and has to work out what to do with it. If it recognises the signature as matching one of the drivers it already has, it will use that. Each piece of hardware has a unique name whether it uses standard drivers or not. The device name and driver signature are independent pieces of information (there loads of others too). This decision and installation process is 'installing device driver' whether it's MS's driver or one from the manufacturer.

React differently?
Because they move data in a different way (synchronous vs asynchronous) and they buffer and handle the data internally in a different way, even though they use the same common driver

Thanks for the explanation, that all makes perfect sense. I had always assumed that if the device used standard MS drivers there would be no install process. I didn't remember there being one for my Pico DAC but I just plugged it in to one of the other slots and sure enough it did an install process as well. You learn something new every day!
 
Thanks for the explanation, that all makes perfect sense. I had always assumed that if the device used standard MS drivers there would be no install process. I didn't remember there being one for my Pico DAC but I just plugged it in to one of the other slots and sure enough it did an install process as well. You learn something new every day!

Hi elnero,

There is no user "install" process as such - well in truth Windows identifies a new device connected and in the case of the MDAC automatically installs a "standard" USB audio driver.

The MDAC identifies itself to the OS - and windows installs its own device driver under the name of MDAC...
 
Hi John (or others who can help me),

I received my M-DAC a couple of days ago from the Canadian distributor.
Even with minimal burn-in, it's definitely a step up from my heavily modded Caiman in terms of sound quality.

There is one problem though. When I'm watching TV and running the audio from the cable box via optical (the only choice) the sound cuts out for about half a second every minute or two. As you can imagine, it's rather annoying. I've tried both optical inputs, and even used our other cable box, but the problem persists. This was never an issue with the Caiman.

I was wondering if any else has experienced this and what you might suggest as a solution, short of sending it back. I know from PFM forums that there have definitely been some QC issues with the first batch of MDACs, and would rather wait a bit if a replacement unit becomes necessary.

Any help would be most appreciated. Thanks. ;)

Bill

Hi Bill,

Its a known issue with the MDAC locking to "Stepping" clock sources (Cable/Sat/DTV) ... there is a software update in the works (installed via the owner via a PC/USB connection).

The update will offer user selective DPLL settings - this trades ultimate Jitter attenuation level for a wider locking range - selectable for each input.
 
I can use the Optical output, it did test bit pefect, but it does cut off the first second or so of a track when you jump to it in a playlist which is only minor but still a bit of an annoyance.

same here - any ideas how this can be solved?
 
same here - any ideas how this can be solved?

If the device or player stops or changes the sample rate between tracks, ie changes from 44.1Khz to say 96kHz and back to 44.1kHz when changing tracks, there's nothing the MDAC can do - its takes about 300mS to re-establish signal lock between changes in sampling rate - you don't really want to be continually changing sample rate for no reason... its bad practice - poor software design.

Does the MDAC indicate change of lock when skipping tracks?

John
 
If the device or player stops or changes the sample rate between tracks, ie changes from 44.1Khz to say 96kHz and back to 44.1kHz when changing tracks, there's nothing the MDAC can do - its takes about 300mS to re-establish signal lock between changes in sampling rate - you don't really want to be continually changing sample rate for no reason... its bad practice - poor software design.

Does the MDAC indicate change of lock when skipping tracks?

John

In my setup it does it all the time when skipping tracks or first playing a track in a playlist.

This is something I've noticed with almost every DAC I've tried via an optical connection in computer setup, the exception would be the Neko D100 MKII I had the pleasure of auditioning a few months ago, I don't remember it doing this.

Please correct me if I'm wrong on this, I've always assumed that this is due to the optical connection only locking when there's a signal present so when skipping tracks it loses lock then has to re-establish it which causes the first second or part of a second to be cut off.

This also brings up another question I've had, given the choice between USB and optical which would be preferable?
 
Hi elnero,

There is no user "install" process as such - well in truth Windows identifies a new device connected and in the case of the MDAC automatically installs a "standard" USB audio driver.

The MDAC identifies itself to the OS - and windows installs its own device driver under the name of MDAC...
Thanks for confirming ChrisPa's explanation John. :)
 
In my setup it does it all the time when skipping tracks or first playing a track in a playlist.

This is something I've noticed with almost every DAC I've tried via an optical connection in computer setup, the exception would be the Neko D100 MKII I had the pleasure of auditioning a few months ago, I don't remember it doing this.

Please correct me if I'm wrong on this, I've always assumed that this is due to the optical connection only locking when there's a signal present so when skipping tracks it loses lock then has to re-establish it which causes the first second or part of a second to be cut off.

This also brings up another question I've had, given the choice between USB and optical which would be preferable?

With a "Decent" Optical source such as a CD player the optical optical output will remain continues - as it should be.

Unfortunately, in our world of "software" writers who do not understand or appreciate the real world of hardware limitations - small details like this are overlooked.

I’ve heard of some software media players that allow a user selectable “pause” at the start of the track to allow external hardware to establish lock.

Depending on your system, but the Async USB allows a Clock lock source (DAC is Clock master, so eliminates the effects of transmission jitter) – while the optical connection gives you galvanic isolation.

It’s a case of what’s worst – the effects of Clock Jitter, or RF and Grounding issues…
 

So, does this mean that even though the Sonos is given a variable frequency output of plus or minus 5Hz, the MDAC is compenstating and therefore there's nothing to worry about?

That said, the Sonos sounds better than the CD Player (which only varies by 1Hz) on identical tracks when they are both going throught the MDAC, so I guess the answer's "yes".

Will you be needing any beta testers for the firmware update? ;-)

Ben
 
John and Dominik,
I was a lucky owner of your CDQ but today I won the lottery! I managed to pick up the m-dac. This machine is absolutely amazing! Right out of the box and cold it blew my mind and the CDQ out of the water. Just to confirm everything I called my brother over who also owns the CDQ, his feelings are the same. So far I have only listened to cd’s (using the CDQ as a transport).
For those of you waiting for shipment, be patient, it will be worth every agonizing day.
John and Dominik, thank you for your hard work, commitment and dedication, but most of all thank you for sharing.
Cheers
Steve
 
Status
Not open for further replies.


advertisement


Back
Top