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MDAC first listen (part V)

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If going for a selected list of input labels (rather than free text, which would require writing more code), I'd offer the same options for all inputs including the USB one. This would be simpler and would allow people with SQBOX to use the USB input (for best results)... One day this may also come in handly for GAME boxes or SONOS too
 
How about a simple HW solution: A small (self made) plaque showing mapping of actual connected devices to current MDAC input names, fitted on a stand matched to MDAC finish :)

It is (hopefully not only) me but I like the current generic input names.
 
Thanks for the answers on headphones. I don't want to buy another amp for headphones so the mdac looks to have killed two birds with one stone. Cheers
 
Mark, yes, the MDAC as a headphone amp works very well, and to be quite blunt I struggle to find any areas to find fault at all with the Mini-via-USB->MDAC->HD800 combination. I reckon from that point on it would simply be slight preferential differences rather than 'better' in any way, shape or form. I'm done!
 
I haven't been around for a few weeks, has the westlake software update come out yet?

I already have the beta version so have fine playback on my V+ cable box, just wondeirng if the full version has been released, or the version with extras like screen off function etc...

MDac's been running lovely, only unfortunately im getting used to the SQ improvement over my old DAC, the novelty has worn off, i haven't been listening to nearly enough music the last few weeks either, naughty naughty, will rectify that this weekend!

Also, what all this talk about a funny 'batch'?
I bought mine on christmas eve UK, should i be checking anything like serial numbers etc?

Thanks ;)


I guess not then....

Sods law after making this post my M-Dac wouldn't switch on last night :(
 
I guess not then....

Sods law after making this post my M-Dac wouldn't switch on last night :(

When its plugin into your PC - does the PC popup with unknown USB device?

If you leave the MDAC powered up for say 1 minute does the display say "Comms Error" ?

If yes to both then its a good chance your MDAC's lost its software - we can update via Email.
 
I'll have to check the USB thing when i get home John, it definitely didn't say 'comms error' though as i left it on for a while thinking it might kick into action as the 'audiolab' sign usually takes a few second to come on... tried switching on/off a few times to no avail

i get the feeling ill go home today & it'll power up as usual, fingers crossed...

thanks for the fast response
 
I'll have to check the USB thing when i get home John, it definitely didn't say 'comms error' though as i left it on for a while thinking it might kick into action as the 'audiolab' sign usually takes a few second to come on... tried switching on/off a few times to no avail

i get the feeling ill go home today & it'll power up as usual, fingers crossed...

thanks for the fast response

Needs to be left on for a minute or so...

Dont worry, Ill sort you out - I promised a new mainboard awhile back...
 
Hi,

Just tried Triodes SBT usb hack with the m-dac.. Sweet :)

One thing: My usb cable is super loose when inserted into the m-dac (loose as in swimming around). The connection seems stabile, but I never saw anything like this with USB cables/devices before.. Normal? Cause for worry?

Cheers
 
Hi,

Just tried Triodes SBT usb hack with the m-dac.. Sweet :)

One thing: My usb cable is super loose when inserted into the m-dac (loose as in swimming around). The connection seems stabile, but I never saw anything like this with USB cables/devices before.. Normal? Cause for worry?

Cheers

Mine is loose, too. Not "swimming around," but definitely loose in comparison to the usb socket into the computer and also in comparison to the other sockets at the back of the mdac. Works fine.
 
Mine is loose, too. Not "swimming around," but definitely loose in comparison to the usb socket into the computer and also in comparison to the other sockets at the back of the mdac. Works fine.

Thanks a lot for that! And sorry about the grandiose prose - Clearly I lack the subtlety of an Englishman :) Anyhow, it is "swimming" though and unlike anything I've seen in USB before. Someone reported the USB port breaking and I need to make sure I don't have a bad unit as this is my last day within my return period.

Thanks
 
The plastic bit in the middle of the usb socket of my mdac came out with the cable one time which was a surprise - glued back in with araldite and been fine since
 
Sorry if already asked in the past:
If I remember well the MDac has no output capacitor for DC decoupling. I am going to connect it directly to a hypex ncore which is DC coupled. If I understand correctly this can cause a problem if the DC offset is too high. But what is too high and how can I check before connecting ?
Thanks
 
Sorry if already asked in the past:
If I remember well the MDac has no output capacitor for DC decoupling. I am going to connect it directly to a hypex ncore which is DC coupled. If I understand correctly this can cause a problem if the DC offset is too high. But what is too high and how can I check before connecting ?
Thanks

Hi jmbulg,

On the grounds of ultimate sound quality (IMO there's no such thing a as good sounding capacitor) - the MDAC is direct coupled - with output DC trimmed to +/- 10mV, with a target of +/- 3mV.

These levels are low, and should not cause problems - give it a try with a cheap speaker - I'd not expect problems.

DC offset protect on the output of any Amplifier is always worthwhile ,

John
 
Sorry if already asked in the past:
If I remember well the MDac has no output capacitor for DC decoupling. I am going to connect it directly to a hypex ncore which is DC coupled. If I understand correctly this can cause a problem if the DC offset is too high. But what is too high and how can I check before connecting ?
Thanks

jmbulg,
If you have a multimeter you can measure the DC offset for yourself pretty easily, just turn everything on (no music playing, no speakers connected), set the amp's volume control to minimum if it has one, set your multimeter to it's lowest DCmV scale, and measure between the ground and the left/right outputs of your amp.

I'm more familiar with headphones than speakers, but even headphone loads don't generally have a problem with 10-20mV, I would only be worried if it was 20mV+, and even then I don't believe that normal DC offset protection circuits will engage before 100mV or more.

If you have a DMM, give it try. The DC offset from my MDAC is 6.5mV at the headphone output, and it's totally stable, which is a fine figure.

./dom
 
Finally coming round to thanking John Westlake for his help in re-uploading the software (firmware?) to my M-DAC after a rare (3 units out of 10,000?) occurrence of a "no comms" issue. Unit happily reproducing/recreating Stan Getz & the Oscar Peterson Quartet's heavenly sounds at the moment.

I would also like to take the opportunity to praise a so far unsung feature: the screen frequency indication takes guesswork out of music track resolution/downsampling/upsampling issues and has been essential for my peace of mind - well done!
 
According to JohnW, "So as long as a decent AC mains filter is fitted to the "PC" and used with our optically isolated Async USB solution, any "PC system" will work as well."

May I ask what a decent AC mains filter might be? No DIY solutions please, thank you.
 
Another quote by JohnW:
"Yes, we could make a small box with a Clock-Lock Async 192kHz Isolated USB converter - I'd rather do this then design a "Olimex usb isolator" type product... It would resolve two issues with one stone... (Async USB 192 + Isolation)..."

Any progress on that front, John? No transport required, thank you.
 
Last post for now, apologies for the rapid-fire succession:

For consideration for the M-DAC software (firmware?) wishlist:

- phase invert switch

- mono switch
 
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