Squeezebox FLAC, Wi-Fi, and the M-DAC bit perfect test!

[WAD62]

FYI The M-DAC comes with an on-board built in bit-perfect test, whereby a couple of sample files are provided 16*44.1 and 24*96, which can be compared to the on-board versions, when a 'Bit perfect' test is executed...

I posted this on the M-DAC PFM thread, but I thought it might also be of interest to SB users, with regard to FLAC & wi-fi;


I've had my M-DAC for some time now, and I'd performed a 'bit perfect' test via my laptop when I first got it, however my normal mode of listening is via an SBTouch, playing FLAC from a QNAP server...

I thought I'd test out the 'Bit Perfect' test using the entire setup, and in the way I normally listen...

So I created a mini album 'M-DAC Bit Perfect Test' with a nice little M-DAC album cover, with the following tracks (FYI I created the FLAC versions using dBpoweramp);

1. 16*44.1 WAV test.wav
2. 24*96 WAV test.wav
3. 16*44.1 FLAC test.flac
4. 24*96 FLAC test.flac

And then rebuild my SB catalogue...

FYI I'm using A0.5 on the M-DAC, EDO 7 on the SBTouch (connected via USB/USB hub/USB galvanic isolator), and LMS 7.7.2 on a QNAP TS-119

And hurrah! it passed each time

Interestingly enough the CPU on my server went through the roof (about 50% cpu) when I was testing the WAV, presumably it must be transcoding on the server, whereas when playing the FLAC tests it was back down to its normal 5%, with the transcoding occurring at the Touch end.

So there's a couple of urban myths dispelled, if FLAC from an SB server transmitted by wi-fi to an SBTouch can produce a 'bit perfect' test at the M-DAC for both 16*44.1 & 24*96 there can't be much (or anything for that matter) wrong with that architecture.

Therefore not much wrong with FLAC and Wi-Fi then, less bandwidth, less storage, less cables, and 'bit perfect'...cue smug face!

[Stratmangler]

Therefore not much wrong with FLAC and Wi-Fi then, less bandwidth, less storage, less cables, and 'bit perfect'...cue smug face!

[WAD62]

...even better Chris, the test was done whilst synchronised to my touch in the Kitchen.

My audio nervosa is (temporarily) sated

[Stratmangler]

My audio nervosa is (temporarily) sated

I completely lost mine when I first heard my current DAC being fed by my Touch - it's a superb bit of kit from M2Tech.

Many thanks to Keith Cooper of Purité Audio, for he supplied the DAC in the first place, and left me for a good period of time to assess it.

[WAD62]

I completely lost mine when I first heard my current DAC being fed by my Touch - it's a superb bit of kit from M2Tech.

...very nice Chris!

I presume you have a decent linear PSU for the M2TECH, just spotted it's 9v, since replacing my receivers I've a couple of spare Maplins linear PSUs that will cover that voltage...

[Stratmangler]

...very nice Chris!

I presume you have a decent linear PSU for the M2TECH, just spotted it's 9v, since replacing my receivers I've a couple of spare Maplins linear PSUs that will cover that voltage...

I've yet to sort that out - an SBooster gives everything a push in the right direction for now

[WAD62]

I've yet to sort that out - an SBooster gives everything a push in the right direction for now

Good aren't they...I was using the PSU in conjunction with an SBooster on the receiver, unfortunately they won't go to 5v, but they do do 9v.

I'm sure there are better linear psu's on the market, but few cheaper, although I'm not sure they do them any more...

[glenann]

Is it worth getting a PSU from Maplins, the £20 one? What voltage does the Touch need, and does the adapters fit ok?
Also is the s booster worth it?

Cheers

[WAD62]

Is it worth getting a PSU from Maplins, the £20 one? What voltage does the Touch need, and does the adapters fit ok?
Also is the s booster worth it?

Cheers

Firstly I don't think maplins do a variable voltage linear PSU any more, secondly the ones I have were no good for the touch as they didn't do 5v (4.5v was the closest), they were good for the Receiver @ 9v and my beresford TC-7510 @ 12v.

I do have the maplins variable voltage SMPS on my SB3 as it's a better one than the supplied one, apparently the Touch's SMPS is better than the SB3's, so I doubt there'd be much point. I ended up coughing up for the Mark Grant one.

However the sbooster is definitely worth it!!!

[glenann]

However the sbooster is definitely worth it!!!

Thanks for that. I'll have a look and probably order one....

Cheers