Interesting I have made some improvments to my system too. One of those was upgrading my mac mini - software, ssd additional memory. It appears I prefer A.08 by a pretty big margain.
MDAC first listen (part XVII)
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Interesting I have made some improvments to my system too. One of those was upgrading my mac mini - software, ssd additional memory. It appears I prefer A.08 by a pretty big margain.
sq225917
Bit of this, bit of that
The Mdac shows them as 24 bit as that is what comes off the iPad using the playback application you have chosen.
Jo Sharp
Pulls on doors marked push
Of course...we all went to Hogwarts where we were taught the dark arts of bodging by Profs Wolstenholme, Weekes & co.
Good work.
On first power on hold the Mdac knob in and check voltages that way.. Do it now on standard psu then compare.. Gives you some idea if something is wildly out.
And let ilus know how much of a step you feel it makes when you brave switching it on....
Thanks for the tip, Sam.
15.9VDC with AC wall wart
15.2VDC with DC PSU
No smoke so far! Following currents measured:
Analog +15.87VDC: 235ma
Analog -15.91VDC: 155ma
Digital +15.94VDC: 390ma
So the 0.7V drop on digital matches the anticipated drop from the bridge diode.
I have about 0.35R resistance on the Analog single wire in the DIN cable (< 2-foot run). I think I will replace the meager 26AWG wires with some more decent 20AWG
RCAs outputs were disconnected. Now for a sound test... (check if there is sound, never mind SQ
)Hi everyone. Been considering buying an M-Dac and came across this thread, very informative! JohnW, great seeing you help so many folks out, gives me lots of confidence in buying one of your designs.
Anyone know of a retailer in Northern Ireland that stocks this/can demo, I've had no luck so far and got no reply when I contacted Audiolab :-( Really keen to try one in my system.
Anyone know of a retailer in Northern Ireland that stocks this/can demo, I've had no luck so far and got no reply when I contacted Audiolab :-( Really keen to try one in my system.
Added a couple more pics, with the M-DAC:
https://plus.google.com/photos/116275103191426331121/albums/5835353298895620801?authkey=CKCaovSqv5WslQE
https://plus.google.com/photos/116275103191426331121/albums/5835353298895620801?authkey=CKCaovSqv5WslQE
Thanks. SQ seems promising. More analog sounding dare I say? it's the first thing that popped in my head when I heard initial material. I just chose something randomly. Going with the feel for now; I'll do the more critical listening later. Listening continues...
Note: the digital supply is quite busy when playing material; the shunt provides an extra 30mA on average and varies quite dynamically (as far as my $100 DMM can tell...)
Martin
PS: many, many thanks to John, to this forum and to fellow PSU builders. You have all made the ownership and enjoyment of the M-DAC an even more special occasion. So glad I found this thread over a year and a half ago.
Note: the digital supply is quite busy when playing material; the shunt provides an extra 30mA on average and varies quite dynamically (as far as my $100 DMM can tell...)
Martin
PS: many, many thanks to John, to this forum and to fellow PSU builders. You have all made the ownership and enjoyment of the M-DAC an even more special occasion. So glad I found this thread over a year and a half ago.
JohnW
pfm member
Well done - welcome to the external PSU club
Very interested in your observation of SQ - let us know
John
sam_cat
C'est Crounchifique!
Few years ago the only electronics I had done was at high school, nothing special. got interested and found the DIY room here... Build a CMOY headphone amp to start with, then a Starfish preamp, B4 preamp, various poweramps etc... Havent looked back since.
If you have an interest pop into the DIY forum and start reading.. To begin with it will all sound like goblidegook, just research anything you dont understand or ask and you will be helped. Its a very rewarding hobby!
Sam
LittleToast
pfm Member
Thanks sq225917 and Plutox for your replies on this.
I use the default music player that comes with ipad to play the files to mdac. The downside of letting it play AAC at 24 bit is that I think D3E is then not switched on as that uses the unused 8 bits if it is a 16 bit music. I thought then the music from the mdac would miss the benefits of the D3E.
Anyway I had an earlier post that nobody responded. I was using the apple tv to stream my music from NAS. But it sounds nowhere near feeding the music directly from the ipad. It is likely due to the fact that appletv resamples and the superiority of the asynchronous usb by John. The problem with using an ipad is that it can't store all my songs in uncompressed format and I thought I can tell the difference between compressed and uncompressed music through the mdac. I wonder how does a mac mini sound compared to the ipad. Any sharing would be greatly appreciated.
With audirvana, 16 bit files appears like 16 bit on mdac and all sounds perfect. I'm not a salesaman of that product but i have to admit that it really does a good job compared to direct itunes playing. Another great advantage is that it mutes all other sounds.
I use it on my macbook pro retina and on my old 17" c2D. Both machines have a good amount of ram (resp 16GB and 8GB) and i cant hear the difference between the two. Btw doing a blind test could be very difficult because i cant switch the usb on the fly
Another observation not related to mdac is that the internal output of the retina sounds bad compared the one of the "old" macbook pro. I use it mainly at work using an "old" senn HD545 reference and the differrence is obvious. Shame on Apple...
br/
I use it on my macbook pro retina and on my old 17" c2D. Both machines have a good amount of ram (resp 16GB and 8GB) and i cant hear the difference between the two. Btw doing a blind test could be very difficult because i cant switch the usb on the fly
Another observation not related to mdac is that the internal output of the retina sounds bad compared the one of the "old" macbook pro. I use it mainly at work using an "old" senn HD545 reference and the differrence is obvious. Shame on Apple...
br/
Hi,
I got my MDAC from Clooney Audio in Dublin which may or may not suit you,
Regards,
Des
LittleToast
pfm Member
With a good dac like the mdac a problem is to find a good machine that can output a good usb to the mdac. The ipad won't work if AAC keeps being played as 24 bit as D3E isn't turned on. Anyway AAC does not sound as good as aiff to me. I need to test it more.
With audirvana, 16 bit files appears like 16 bit on mdac and all sounds perfect. I'm not a salesaman of that product but i have to admit that it really does a good job compared to direct itunes playing. Another great advantage is that it mutes all other sounds.
I use it on my macbook pro retina and on my old 17" c2D. Both machines have a good amount of ram (resp 16GB and 8GB) and i cant hear the difference between the two. Btw doing a blind test could be very difficult because i cant switch the usb on the fly
Another observation not related to mdac is that the internal output of the retina sounds bad compared the one of the "old" macbook pro. I use it mainly at work using an "old" senn HD545 reference and the differrence is obvious. Shame on Apple...
br/
Audivarna is pretty special, big fan.
technobear
Ursine Audiophile
Yes, the isolators only support 'Full Speed' or 12 Mbps, they don't support 'High Speed' or 480 Mbps.
I use the Big Bear USB2ISO 2.0 Full Speed (the Danish one). It works fine at 24/96.
The idea of 'headroom' doesn't apply here.
I wouldn't choose a player based on the number of bits which the AAC decoder produces. The best audio quality will come from a lossless codec or uncompressed format (wav/aiff/flac/alac). AAC is lossy and this means the decoder won't produce exactly the same bits as the original material. The fact that some decoders produce 16 bits and some 24 bits is down to a software configuration chosen by the designer of the decoder - its probable that the output is actually more accurate (to the first 16 bits) if it is computed to 24 bits of resolution, so the 24 bit case may be more accurate. However if you are worried about D3E I'd suggest you should think about lossless codecs not aac.
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