JohnW
pfm member
Hi Dom,
Sorry, I'm sure I've already replied a while back with PSU voltages and current requirements, from memory:-
+15V Digital 400mA
+15V Analogue 250mA
-15V Analogue 140mA
MDAC first listen (part V)
- Thread starter Oktane
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Hi Dom,
Sorry, I'm sure I've already replied a while back with PSU voltages and current requirements, from memory:-
+15V Digital 400mA
+15V Analogue 250mA
-15V Analogue 140mA
JohnW
pfm member
I have no idea of the amplifiers topology - but I'd guess at a pretty standard "Lin" type design with Ground Ref. Diff input pair and (as the Avondale circuit linked above) - I'd guess its be OK to remove the Cap.
You can always check the DC levels before and after the Mod - MDAC connected, no speakers.
gh0st
pfm Member
Thanks John. You did indeed reply a while back, I just wanted clarification because at the time you were talking about an internal mod you said you might offer which did something to the rails internally. I just wanted to the make sure that this 3-rail config was the same without such a mod.
./dom
Thank you
gh0st
pfm Member
Ah I see. I can't afford to provide five separate rails, so I'll stick to the three
A quick diagram of the pins on the connector would help a lot.
cheers ./dom
PhilCTTE
Senior mumbler
John being doing some research and these latest Asus mini itx mobos look good for the MITX build (ASUS F1A75-I Deluxe) wifi dvi out latest spec
http://uk.asus.com/Motherboards/AMD_Socket_FM1/F1A75I_DELUXE/
http://www.dabs.com/products/asus-f...-hudson-fm1-ddr3-mitx-7QJW.html?q=mitx&src=16
http://www.silentpcreview.com/forums/viewtopic.php?f=20&t=63763
Will you have a specific mobo in mind when designing cooling and casework ?
Are we looking at this year ? MAMP and MPAX first I guess?
http://uk.asus.com/Motherboards/AMD_Socket_FM1/F1A75I_DELUXE/
http://www.dabs.com/products/asus-f...-hudson-fm1-ddr3-mitx-7QJW.html?q=mitx&src=16
http://www.silentpcreview.com/forums/viewtopic.php?f=20&t=63763
Will you have a specific mobo in mind when designing cooling and casework ?
Are we looking at this year ? MAMP and MPAX first I guess?
Just a quick report back as promised about the 'normal' listening levels on the system while driving the power amp with the MDAC directly, during my weekend dem- about the maximum level I ever had set was -28dB listening to certain classical tracks quite loudly. Most rock/pop had to be turned down considerably lower at about -40dB or so and was still fairly loud.
In any case, I found that in my system this didn't produce desirable results, the sound lost it's 'substance' quite dramatically, so I went back to using the preamp which improved things greatly. Ultimately though, for all the things the MDAC got right, and there were many, it's not the sound for me, but was a fascinating listen in terms of my first experience with computer->DAC audio. I'm sure this is the way of the future, although maybe with a solution which simply places an HDD or SSD inside the player (a CD player with a hard-drive instead of an optical drive, if you will, like the Naim HDX or Meridian MC200). Sound quality aside, I found the whole experience of fiddling about with computer settings, network cards, yada yada, very dull- after a couple of days I longed just to open an album and pop the CD in the drive!
The other thing I tried was one of the Olimex isolators, which did make a difference, but sadly for the worse- everything became flattened and with a tooth-grinding glare to it. Anyone want to buy mine?!
I'd be fascinated to try an MDAC with the PSU mods John is working on, and a more accurate clock locked dedicated transport, again with proper attention paid to PSUs, jitter, etc., to see how things improve, though, and wish you every success with its ongoing development!
John_73
pfm Member
Think I have a problem with my MDAC - I'm randomly getting 'tics' of sound through the left channel only - sounds very similar to the effect you get when playing a record that's full of static! It's only on USB (using PC or Mac). Cycling the input selector off of USB, and then back to it seems to cure it, until the next time. It's been fine for well over a month or so and this has only recently started - no changes made to the computer in that time.
Cable is fine, all settings are as per the instruction manual. Hoping this isn't a sign of some imminent failure - has anyone else experienced this? I'm going to try a different cable just to make sure it's not that, but it must be within MDAC for it to only affect one channel I would have thought...
- John
Cable is fine, all settings are as per the instruction manual. Hoping this isn't a sign of some imminent failure - has anyone else experienced this? I'm going to try a different cable just to make sure it's not that, but it must be within MDAC for it to only affect one channel I would have thought...
- John
JohnW
pfm member
Hi John,
Try with D3E Enabled if its currently disabled.
The ESS DAC has a design bug, it can miss-lock on the left channel, we have a work around that reduces the Miss-lock events... As its a design bug in the ESS silicon we cannot resolve 100%, but we VERY rarely experiences the event.
I wounder why its "Become" a problem in your system - I don't believe the software has been changed concerning the operation in USB mode.
Are you streaming 24Bit data?
John
JohnW
pfm member
JohnW
pfm member
Hi Phil,
Planning to use an Intel DH61AG - decent quality and supports i5 and i7 with DVI and HDMI - unless a better option comes up?
BDAC, MPAX, MTRN, MAMP & then MITX...
John
JohnW
pfm member
that'll need a lot of cooling. I don't think you'll need anything more than an atom 525
John_73
pfm Member
Thanks for your speedy reply John!
Yes it is strange - D3E is set to full suppression already. The only change I have made recently was installing that pre-release firmware update of a couple weeks back. Come to think of it I've only been getting this since then so perhaps that could be it? Unfortunately it's random so I cannot get a handle on exactly when/why it occurs. Sorry I realise that doesn't help you much! Occurs with 16-bit Apple Lossless, WAV, AIFF or (spit!) MP3. I rarely play high-res files so not sure if that's affected too. Will keep an eye (ear!) on it to see if I can pin down any pattern to it...
Is the official version of the firmware imminent by the way? I haven't checked this thread for a few days.
- John
I totally agree....
The DH61AG is a very interesting motherboard which should satisfy many of us in terms of features (heat dissipation may be a concern as highlighted by others).
My only concern is that the H61 chipset was introduced over a year ago, which means that a replacement of this board may become available before the MITX is released... actually there is already a replacement for it, called the DQ77KB
My only concern is that the H61 chipset was introduced over a year ago, which means that a replacement of this board may become available before the MITX is released... actually there is already a replacement for it, called the DQ77KB
ddenyer
pfm Member
Had a very strange thing yesterday (first malfunction since new - a few months). I was listening fine, then I switched track, and volume & distortion went though the roof, switched again & it was OK, back to the "problem" track and it was OK too. a second track then also showed the same behavior. Power cycling the MDAC cured it. Anyone else had this?.
Derek
Derek
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