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MDAC first listen (part XVIII)

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atchi123 said:
having a few niggles with the MDAC. Firstly sometimes when I turn on the device the USB input states -80db and has no sound despite a connection. other times there is activity on the MDAC screen i.e. the db bars are moving but no sound. several random re-boots of the DAC and the Squeezebox eventually resolves the issue but would be good to understand root cause. I think this has happened with most firmware versions.
MDAC (A.10) USB to SB Touch (EDO mod) and using XLR outputs.
Thanks!!
Click to expand...

Yes, my problem aswell. Maybe we need a new thread on this to get some focus on the characteristics.. I always get mine back by cycling the MDAC, don't need to touch the SBT.

Tony
 
Hello jirij, hello Adrian, hello gh0st,
thanks for your help with the RPI.
This is the reason I love this thread so much and reay read it every day.
Till now I´ve testet several settings in ~/.asoundrc, mpd.conf and modprobe.d/alsa-base.conf. I´ve also tested the image from here: http://www.raspyfi.com but every time only crackling over usb.
My target is to built a little audio player with usb-audio out for the MDAC. It would be no problem to buy an other mini PC if I would know usb audio-out will work. Today I´m using an old AirportExpress over optical for Airplay. This works realy well without any pops or dropouts like the new model does but I know connection over usb would be an big improvement in audio quality. So if anybody knows a solution for using usb-audio out I would be really pleased.
Greetings to everybody out there!
 
Gomez said:
Would this be the same for -20dB Balanced into a Meridian 557 power Amp ?
That's currently tiding me over until your amps a ready :D

Cheers Gomez....
Click to expand...

Hi Gomez,

I checked the 557 user Manual but theirs no mention of the input impedance for its RCA or XLR inputs.

Yes, the attenuator will work - as we don't know the amplifiers input impedance there might be a slight attenuation error (i.e very slightly greater or slightly less then -20.3dB)...
 
atchi123 said:
having a few niggles with the MDAC. Firstly sometimes when I turn on the device the USB input states -80db and has no sound despite a connection. other times there is activity on the MDAC screen i.e. the db bars are moving but no sound. several random re-boots of the DAC and the Squeezebox eventually resolves the issue but would be good to understand root cause. I think this has happened with most firmware versions.
MDAC (A.10) USB to SB Touch (EDO mod) and using XLR outputs.
Thanks!!
Click to expand...

The next time you experience the issue (there is activity on the MDAC screen i.e. the db bars are moving but no sound) try cycling the digital filters and let us know if this restores audio.

The MDAC should never powerup at -80dB* (unless it was set to -80dB just before being powered-off in the last session). We would need more information to better understand what's going on here... if your unit commonly powers-up at -80dB* then I'm inclined to suspect a hardware issues...

*Just a thought - insure that under the MDAC's Menu option the "USB Volume" option is set to "Deny Control" - if its set to "Accept Control" maybe the USB host device is setting the Volume to minimum upon each enumeration.
 
Thanks John much appreciated that's close enough for me.
I'm looking forward to your Amp's, do you think a pair mono blocked, would drive my Sonus Faber Cremona's ( floor standing original's not M ) much better than the 557 ? and will they have built in Attenuation ?

Gomez...

JohnW said:
Hi Gomez,

I checked the 557 user Manual but theirs no mention of the input impedance for its RCA or XLR inputs.

Yes, the attenuator will work - as we don't know the amplifiers input impedance there might be a slight attenuation error (i.e very slightly greater or slightly less then -20.3dB)...
Click to expand...
 
Gomez said:
I'm looking forward to your Amp's, do you think a pair mono blocked, would drive my Sonus Faber Cremona's ( floor standing original's not M ) much better than the 557 ? and will they have built in Attenuation ?
Click to expand...

Good Question - obviously I'd like to think so :) - I don't know the cost of the 557 but by the description its based upon the Bob Cordell type Error correction output stage - this is a competent design.

If your ok with 120W, I think A pair of Mimps will work very well - lets see :)

Yes, the Mimps have built-in "Automatic" attenuation - controlled by the MDAC's Comms Bus..
 
Thanks for taking time to reply out of your busy schedule, I find it quite incredible that I can actually ask questions and indeed get answers from the actual designer fo this amazing bit of kit.
It makes such a refreshing change to have someone in the Hi-Fi industry that stands by thier products and cares about the end users. You deserve to do extremely well and I hope that you do.

All the best...
 
jirij said:
Not directly on RPI, but I run MDAC on Debian ........
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The word "Debian" here arouses my interest as to which OS do sound the best with mdac, and also BTW what player (foobar, sawstudio, audition, wavelab....) sounds the best with mdac? I don't think "bit perfect test" is the only yardstick such that all other factors such as different OS and players have nothing to do with sq, am I right? :)
 
I will be (virtually?) killed for this, regarding project loads etc. However, just to express my very own needs, a suggestion:

- a high quality DAC with pre-amp function
- asym USB and optical, even not user selectable (the one with the signal gets selected)
- balanced and RCA out
- no display
- no filters or very few (somehow LED indicators? would prefer without; or user upgradable for hard core types...)
- headphone out

possibly:

- internal power adapter - if it can be done without too much interference :-(
- low depth enclosure (think minimal book shelf, i.e. 16cm leaving some cabling space)

Basically a "headphone DAC", but with regulated levels = pre-amp section (think stripped down MDAC). The perfect use scenario (speaking for myself) would be single a source digital => active speakers chain (or digital => MIMP => speakers).

Just dreaming here ... But I've surveyed the market, and either there is no regulated out or very headphone centric, or/and the quality doesn't cut it. So something which just drives a pair of Adams or other active speakers (which seems to become fashionable!), or a nice power amp from a computer/AE/ATV/streamer ...

Food for thought? But MIMPs first, please ;-)

Michael.
 
lapkwan said:
The word "Debian" here arouses my interest as to which OS do sound the best with mdac, and also BTW what player (foobar, sawstudio, audition, wavelab....) sounds the best with mdac? I don't think "bit perfect test" is the only yardstick such that all other factors such as different OS and players have nothing to do with sq, am I right? :)
Click to expand...
I wasn't suggesting that it influences sound quality, my interest was really just "works / doesn't work" - at least Ubuntu and Fedora have pulseaudio enabled by default, so rather than Debian, I could have said "I run a minimalistic userspace, just like RPI". But since - as far as I know - the primary distribution for the RPI is Debian, I simply wanted to indicate a system similarity to my (working) setup.

By the way - my choice of Debian has absolutely nothing to do with audio. In fact, I run non-standard kernels.
 
I've heard of comments saying that foobar is not the best music player for mdac or other dac, there are others like wavelab and sawstudio(paid software quite expensive), is it true? :)
 
lapkwan said:
I've heard of comments saying that foobar is not the best music player for mdac or other dac, there are others like wavelab
Click to expand...

Wavelab, which I know well, is entirely unsuitable as a player - it is high end audio editing and manipulation software. It only supports Windows direct sound (i.e. via the kernel mixer) or ASIO, which in turn requires your audio playback hardware maker to supply ASIO drivers.

To use Wavelab as a domestic music player is rather like using a farm tractor to go on a 500km motorway drive.
 
Until you try it for yourself- what do you have to lose, just think how much simpler your life might become. I thought i could hear all sorts of differences between cables and software, I surprised myself to find out that i couldn't. And make a packet selling all my foo for studio wire in the process...
 
John,

Update on my 'freezing' MDAC issue. As I told before, I replaced version a.10 with v0.90, after which my MDAC froze again, immediately upon start. Thing is that my MDAC was initially shipped with version 0.99. Today I reinstalled v0.99 and the MDAC works without any problems. Then I reinstalled 0.90 again and it freezes again. Also with a0.4 and up.
It looks like it simply freezes up on any other version than its original version, although according to me it did work for some days with v0.9. Not sure anymore though... I do have one of the latest MDAC's that's shipped. Any idea with these new thoughts?
Update on update:
Got v.0.99 installed, when I turn off my MDAC and turn it on again while pressing the volume control, the MDAC shows the voltage. Pressing the volume button again shows the 'lake west' logo, which assumes that lake west software is installed, while mainboard/control versions are v0.97/0.99. It appears like the a.xx versions leave something in memory, which may also cause that all lakewest versions do not work properly anymore. ...
 
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