MDAC first listen (part VII)
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GrumpyOldMan
Active Member
Well, off to a bad start... Got my black M-DAC today (via Planet of Sound in Canada) and it showed a "No Comms" message when I first turned it on. I tried USB via Windows, USB via Mac, and finally TOSlink via MAC. Can't get in the menus or do anything. Restarted it a few times, unplugged the power, no dice. Did I just buy a close-to-$1K doorstop? Could it be just a loose connector/IC inside? Or do I have to find some way to already get warranty service in the US?
I want to clarify that both the Mac & Windows recognize the device (Texas Instruments AudioLab M-DAC, firmware 0.90) both via USB and TOSlink and send music to it, but of course not a peep can be heard via headphones (and the volume control doesn't seem to do anything either)
I want to clarify that both the Mac & Windows recognize the device (Texas Instruments AudioLab M-DAC, firmware 0.90) both via USB and TOSlink and send music to it, but of course not a peep can be heard via headphones (and the volume control doesn't seem to do anything either)
I am using the official Spotify client for Windows. In Windows environment its more an exception than a rule that application supports Asio. Even if the Asio4all is installed, the application needs to specifically support the feature. Most applications are just using regular DirectSound audio, which of course has its problems.
To my knowledge Spotify does not support Asio, or have I missed something?
I am not sure what causes the peak limiting. I have read somewhere Spotify does that (even if volume normalization is off), because otherwise the modern recordings with 0dB peaks would cause digital errors (go "over" 0dB, edit: or just hard limiting) after decompression of the lossy (ogg vorbis) stream. But then again, I can't be sure and after second thought it does not make sense, unless the version of ogg vorbis codec they are using is buggy.
I got asio4all/KS/Wasapi set up for applications that supports it.
That was exactly the idea. Great!
JohnW
pfm member
Are you sure its reporting "Texas Instruments AudioLab M-DAC, firmware 0.90"
Why Texas Instruments?
GrumpyOldMan
Active Member
I read up on previous posts with this error, and having nothing to loose, tried the latest update (Mainboard v0.98, Control v0.99) via Windows 7 in VMware Fusion 4.1.2.
The good news is that the update utility sees the M-DAC, transfers the files and lets it restart (I assume, it just turns black after that) So at least I can confirm the updatability via a Mac virtual machine...
The bad news is, just seems to update the mainboard, going back to the utility for a second time I get:
Found M-DAC running:
Mainboard v0.98
Control v0.00 (<-?!?)
Proceed with update? Yes
Updating Mainboard:
Done in 2.38s
Replied 'R'
(no mention of updating Control...)
So I guess it may be a loose connector. Is that something easy to fix (I have taken apart, put together and often fixed my share of hardware)
The good news is that the update utility sees the M-DAC, transfers the files and lets it restart (I assume, it just turns black after that) So at least I can confirm the updatability via a Mac virtual machine...
The bad news is, just seems to update the mainboard, going back to the utility for a second time I get:
Found M-DAC running:
Mainboard v0.98
Control v0.00 (<-?!?)
Proceed with update? Yes
Updating Mainboard:
Done in 2.38s
Replied 'R'
(no mention of updating Control...)
So I guess it may be a loose connector. Is that something easy to fix (I have taken apart, put together and often fixed my share of hardware)
GrumpyOldMan
Active Member
Yes, I was a bit surprised too, but it doesn't anymore after the partial update... I guess there's a TI comm chip in there somewhere? Maybe a mis-identification by OSX?
JohnW
pfm member
It could well be that the Cable between the Mainboard and front panel has come loose...
If you want to try for yourself:
Using a Torx T5 driver remove the front panel screws
Pry away the front Panel carefully - you will find a black flat foil cable that connects the front panel to Mainboard - see if this is fully seated home.
If it looks OK:
Fully unplug the flat foil cable from the front panel
Remove the rear panel Torx T5 screws
Slide out the DAC PCB about half way - you will see where the Flat foil cable is seated within the Mainboard - insure its fully seated home...
Reassemble the unit... (Don't forget to insert the front panel cable).
John
JohnW
pfm member
When you first run the software, did it report the front panel (Control) firmware versions? (V0.90 / V0.90) etc
It must be a loose cable (If your "lucky") - I worry if the cable or connectors where not damaged during production
Krisposs12
Active Member
Just in case anyone might be interested, and given my obsessive nature in general, I did some basic experiments with the M-DAC with the anomalous frozen high-level digital input from my STX sound card. I could have just measured the DC output from the M-DAC with a multimeter, but I don't have one. So I did the following:
Playing the M-DAC BPT test file through ASIO, I paused playback with a high (close to 0dB as per the M-DAC level indicator) input on a single channel with the other channel low, and set the M-DAC volume at -1dB to ensure a high DC output at the headphone amplifier. I then plugged in each of the following: (a) a cheapo pair of Nokia earbuds that came free with a mobile phone (~16ohms); (b) Sennheiser HD201s (24ohms); and (c) Sennheiser HD497s (32ohms). I left them in that state with a constant high DC input for around 30 minutes.
After 30 minutes, the Nokia earbud channel corresponding to the high level got somewhat warm as you'd expect from the coil heating up, but not to the point of burning (no smell) and functioned as normal afterwards with no detectable degradation in quality (they sounded equally poor before and after). After letting them cool, setting the volume to -14dB and plugging them in for another 30 minutes, this time they did not show any noticeable temperature increase.
At the high volume setting of -1dB, both pairs of Sennheisers had no detectable increase in temperature in either ear and again no degradation in performance afterwards.
So if you're using a decent pair of full sized headphones there does not seem to be any risk to them under normal use with the M-DAC at high volume and an anomalous high DC digital input such as that from the STX (which note disappears during playback). Which is a relief to me and my more expensive Senns and Grados.
Oh, and Asus gave me the stock instruction to RMA the sound card even though it's not a hardware fault. What a surprise. Not holding my breath for a driver update.
Sorry again John for all the hassle and questions, but if it's any consolation I learned a lot from your posts. You have my gratitude for that!
Best regards,
Krisposs
Playing the M-DAC BPT test file through ASIO, I paused playback with a high (close to 0dB as per the M-DAC level indicator) input on a single channel with the other channel low, and set the M-DAC volume at -1dB to ensure a high DC output at the headphone amplifier. I then plugged in each of the following: (a) a cheapo pair of Nokia earbuds that came free with a mobile phone (~16ohms); (b) Sennheiser HD201s (24ohms); and (c) Sennheiser HD497s (32ohms). I left them in that state with a constant high DC input for around 30 minutes.
After 30 minutes, the Nokia earbud channel corresponding to the high level got somewhat warm as you'd expect from the coil heating up, but not to the point of burning (no smell) and functioned as normal afterwards with no detectable degradation in quality (they sounded equally poor before and after). After letting them cool, setting the volume to -14dB and plugging them in for another 30 minutes, this time they did not show any noticeable temperature increase.
At the high volume setting of -1dB, both pairs of Sennheisers had no detectable increase in temperature in either ear and again no degradation in performance afterwards.
So if you're using a decent pair of full sized headphones there does not seem to be any risk to them under normal use with the M-DAC at high volume and an anomalous high DC digital input such as that from the STX (which note disappears during playback). Which is a relief to me and my more expensive Senns and Grados.
Oh, and Asus gave me the stock instruction to RMA the sound card even though it's not a hardware fault. What a surprise. Not holding my breath for a driver update.
Sorry again John for all the hassle and questions, but if it's any consolation I learned a lot from your posts. You have my gratitude for that!
Best regards,
Krisposs
GrumpyOldMan
Active Member
Sorry, didn't pay attention to that the first time around, even though I realize in hindsight it may have helped pinpoint the issue.
I tried re-seating the cable 3 times on both ends, to no avail. I even flipped it, but same "No Comms" screen. For all it's worth, based on the grooves on the cable, it looks like all the pins of both sockets have a good connection.
So I guess it's either the cable itself though I couldn't detect physical damage (it was folded over pretty hard at the main board socket) or the flash memory has an issue. Though I guess that would result in a different error than "No Comms", and the utility should have at least attempted to flash it... I see the front panel has a diagnostic connector, but I'm not equipped for that.
It would nice to try a different ribbon cable but it's not like a generic USB cable etc., I'm not sure where I could get ahold of one (the right type at least, regardless of the length)...
Anyway, gotta head out for work.
JohnW
pfm member
Sadly I expect its not the cable - can you not return your unit under warranty?
If not I'll have to post you some parts...
Not sure if the front panel first or a Mainboard...
Sending anything from Czech Rep. to the US is a pain... (still I'm happy not to be in China).
John
bigmarcelo
pfm Member
I'm sure some of these have been mentioned already... just getting it started again ...
dim / blank screen - timer based if possible
input naming
lake west logo - rather then audiolab coming up
display which could show the bit rate (to check if the file played is FLAC, AAC, ALAC, etc.)
could both the USB buffer and the level volumes be displayed at the same time?
could we have an option for a screen that displayed the volumes with 'needles' like in old receivers?
that's me.... thanks!!
GrumpyOldMan
Active Member
Thank you much for your help, I'll see what the dealer has to say.Sadly I expect its not the cable - can you not return your unit under warranty?
If not I'll have to post you some parts...
Not sure if the front panel first or a Mainboard...
Sending anything from Czech Rep. to the US is a pain... (still I'm happy not to be in China).
John
Since the mainboard flashes OK and responds to USB, I'd think it would be more likely the front panel... replacing the mainboard would be pretty much like replacing almost the entire thing, wouldn't it?
John,
Most of what I would like has already been included in the Lakewest build I believe - input names etc
However the post above would be quite possibly the best addition I could have to the MDAC. Some of my iTunes library is in the old 128kbps but most of it is apple lossless so it would be really helpful to tell which was which just by looking at the MDAC. Especially because all my music is CD format so the 16/44.1 display never changes on my MDAC unless I listen to the radio!
Regards,
James
Why is this John?
fusion5
on the dark side of hifi...
I would like discrete remote codes for digital filters and inputs. Then I could ask Logitech Support to build a new Harmony profile for the Lakewest M-DAC.
Michael
Now if I was managing this project....
John, you mentioned earlier that the key to the Lakewest build was to move some functions from the main board to the front panel processor (or was it the other way about??).
In your shoes, I would suggest that Dominik makes a build that does nothing more than this - no new features whatsoever, but simply takes the existing .99 stuff and make this change, then let that build settle for a month or two before introducing any new features. If any small oddities slip in because of the move from one processor to the other, things could easily become very confusing once new features start creeping in.
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