MDAC First Listen (part 00011111)
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JohnW
pfm member
I'm wondering - as an "Option" we could also use the Vishays in the ADC circuit for those who also want the very best ADC performance.
By design to optimise performance the MDAC2 Analogue signal path is much simpler then the MDAC - although its a more complex circuit, we might only require 12 Vishays for the "Max" version or we could go crazy - it just depends on the results of the listening tests.
fusion5
on the dark side of hifi...
Have just bought a 2 month old MDAC, which was sold as working. Display and front panel controls working OK but irrespective of whatever input is used, coax, opto or usb, there is no output, any suggestions?
No problem with same inputs to another DAC so not a source problem.
No problem with same inputs to another DAC so not a source problem.
fusion5
on the dark side of hifi...
Is the MDAC receiving a signal? Any response on the level meter? In this case it might be a stucked relay.
JohnW
pfm member
Have your tried to cycle the power? are the level meters moving to "Music" - if they are and you have no sound, then try cycling the Digital filters.
Dont worry I can repair the unit for free if theirs anything wrong - you would just need to cover the shipping cost.
Not sure what you mean by cycling the power, can you please advise?
There is no movement of the level meters? The RAW front panel displayed voltage is around 16.4V?
Any suggestion as to what might be wrong in this situation? Is it likely that a connection has become dislodged during transit?
No response on the level meters. Does that indicate a stuck relay, if so how do you 'un-stick' it? I assume it requires removing the panels? If I insert a headphone plug into the headphone socket you can hear relays clicking.
JohnW
pfm member
Sprint,
Which Digital input are you using? - how have you connected the MDAC to your digtal source? Its strange that the level meters are not moving.
When you select the input connected to your digital source the MDAC should indicate the sample rate - even when Music is not playing.
If the MDAC displays "unlocked" then there is no Digital signal to the MDAC (if your using Coax or Optical Digital input) - insure you have connected the Coax cable to input 1 or 2 and NOT to the digital output.
By "cycling the power" I mean to Power the MDAC Off wait 5 seconds and then power On again.
Which Digital input are you using? - how have you connected the MDAC to your digtal source? Its strange that the level meters are not moving.
When you select the input connected to your digital source the MDAC should indicate the sample rate - even when Music is not playing.
If the MDAC displays "unlocked" then there is no Digital signal to the MDAC (if your using Coax or Optical Digital input) - insure you have connected the Coax cable to input 1 or 2 and NOT to the digital output.
By "cycling the power" I mean to Power the MDAC Off wait 5 seconds and then power On again.
JohnW
pfm member
No, level meters not moving indicates that there is no digital input signal - nothing to do with Relays.
If your using USB then insure that the MDAC is selected as your active sound device in your computers sound settings.
JohnW
pfm member
The Amps follow the MDAC2 - I can see MDAC2 keeping me busy until the end of the year with production and support.
I'm very keen to launch the amps - I have x5 quad 240's that will be used as donor chassis for the prototype - a few of these units will be launched before for "feedback"
I'm very keen to launch the amps - I have x5 quad 240's that will be used as donor chassis for the prototype - a few of these units will be launched before for "feedback"
delange
pfm Member
The Amps follow the MDAC2 - I can see MDAC2 keeping me busy until the end of the year with production and support.
I'm very keen to launch the amps - I have x5 quad 240's that will be used as donor chassis for the prototype - a few of these units will be launched before for "feedback"
I'm in the market for probably two power amps. The idea is to hide them behind the speakers. They need to drive a pair of Focal 1028 Be, which are very easy to drive speakers. I just need some time to prepare myself mentally to part from my existing amp... will not be easy
davidjt
pfm Member
JohnW,
Assuming that all options will use the same 2 pcbs, might it be possible for a basic MDAC2 to be upgraded later on? (Personally, I wouldn't risk removing smd components from a crowded board, but cutting a link or two and adding new parts could be feasible.)
I used to be indecisive, but now.......
Assuming that all options will use the same 2 pcbs, might it be possible for a basic MDAC2 to be upgraded later on? (Personally, I wouldn't risk removing smd components from a crowded board, but cutting a link or two and adding new parts could be feasible.)
I used to be indecisive, but now.......
Hi John
Have taken photo of connections, but can find a way to add/link it to post, but the all connections are correct and to inputs and not the output. I have a seperate coax, opto and usb connections to the MDAC.
All displays are showing 'unlocked' with no movement on level meters and no sample rates displayed on any input.
Coax is from a SBT and usb directly from Vortexbox unit. If I make the same connections to another DAC no problems?
Have tried cycling the power on and off about 30 times to no effect.
JohnW
pfm member
At this time I'm not intending to produce a second production batch of MDAC2's (after we have fulfilled the pledged / At cost upgrades units) to this end we will not have excess stock of various build PCBs - each customers unit will basically be built to order.
Each build level (DSP / ADC) has a significant amount of extra components - and not something that I'd even entertain to hand build (apart from the prototype units) - not to mention a different rear panel for the ADC versions.
JohnW
pfm member
Really really odd - it does seem like your unit has a problem, and its not related to the MDAC's "Stock Faults" the Crystal or Relay.
I've not encountered this problem before - so I'm at a loss to suggest a cause - unless the Cable to the front panel has come loose - or been damaged if someones opened the unit and had a poke around inside....
I've had many MDAC's through my hands, and with very few problems... just very odd, my rather cynical side wonders about this units history...
Please Don't worry, I can repair the unit for you for free - you would just need to cover the shipping costs... Unless your near the IAG service in Huntingdon and they could take a quick look...
Thanks for the reply.
The unit does not look to be touched as none of the Torx screws have any damage to their heads. Unit has been loaded with LW 0.9 firmware though.
As far as I have been told it only a couple of months old.
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