Alien DAC v1.1 Construction Thread
Aug 13, 2008 at 2:06 AM Post #1,366 of 1,562
I didn't explore all the options for shipping but the last time I checked for Mouser they wanted $19US in shipping. DigiKey Canada is $8 flat rate, next day, no taxes or duty (they ship from Winnipeg).

Thanks for the part number error401. I've got one or two items that I also want to get from DigiKey so it helps.

Back to soldering the through holes items...
 
Aug 13, 2008 at 4:25 AM Post #1,367 of 1,562
I do have a reasonable electronics shop, but the don't carry a single item that is SMD.

Should I be seeing any offset on the output? From OL to OG, I'm seeing 11mv and from OR to OG, I'm seeing about 8mv.

I did hook it up to my cmoy with input caps, so nothing on the output there, and sound is good from both channels.
 
Aug 13, 2008 at 4:55 AM Post #1,368 of 1,562
Quote:

Originally Posted by cobaltmute /img/forum/go_quote.gif
I do have a reasonable electronics shop, but the don't carry a single item that is SMD.

Should I be seeing any offset on the output? From OL to OG, I'm seeing 11mv and from OR to OG, I'm seeing about 8mv.

I did hook it up to my cmoy with input caps, so nothing on the output there, and sound is good from both channels.



Usually it's just the output caps charging. Connect a load for a few minutes and then measure again with the load connected.
 
Aug 13, 2008 at 6:10 AM Post #1,369 of 1,562
Thanks Alf!

Received this kit from Jeff Rossel (thanks to you for the service you provide) yesterday, and put it together last night. It worked first time (more to do with ordering the pre-soldered dac chip than anything else!) and left it running overnight.

Very, very impressed with the SQ. Like others have mentioned, you get a lot of air and space around the instruments, and a good dollop of detail. Massively better than the onboard sound of my Dell D610 (Work supplied), which had a very intrusive sound floor.

For reference, I'm listening via a Pimeta with LMH6321 buffers, biased to class A. It's supplied by an off-board dual rail PSU and filtered by an JLH ripple reducer, which makes a HuGe difference.

Kings X has never sounded so good.
 
Aug 13, 2008 at 10:39 AM Post #1,370 of 1,562
Quote:

Originally Posted by error401 /img/forum/go_quote.gif
Usually it's just the output caps charging. Connect a load for a few minutes and then measure again with the load connected.


I'll have to try it again later tonite. While testing, I had waited for the offset to come down (it had started much higher), but it seemed to have stabalized at the 10mV level. I didn't think that it would take that long for the capacitor to charge with no load.
 
Aug 15, 2008 at 4:36 PM Post #1,371 of 1,562
I hooked up the DAC to my laptop for the first time and I got some really bad sound... It sounded really garbled, almost like static on the radio.

It works perfectly out of my desktop's USB, so I don't understand what could be wrong. I will check the voltages when I get home today (I forgot to do that) but is there anything else that could be causing this problem?

In case it matters, the laptop is an old Sager 8790, Windows XP, and I installed the ASIO driver that Jeff recommended (although I don't know anything about ASIO per se.)
 
Aug 17, 2008 at 2:08 AM Post #1,373 of 1,562
Quote:

Originally Posted by cobaltmute /img/forum/go_quote.gif
Check your connector wiring. When I first hooked my up (with alligator leads), I had perfect sound from one side and garbage from the others. Turned out it was just bad connections.


I'm certain it's not the connectors (I have it hooked up via alligator leads as well at the moment.) I can switch the USB cable between my desktop and laptop computers without changing anything else, and the sound on the laptop just sucks.
 
Aug 17, 2008 at 9:43 AM Post #1,374 of 1,562
I have an AlienDAC which I built quite a while ago and have been using regularly. I loaned it to a friend and it stopped working when he has it. I found that there is now no output from the adjustable voltage regulator.

Is it possible for the adj voltage regulator to get damaged when the 3.3V regulator is fine?

Is there anyway to find out if the adj voltage regulator is damaged?

Thanks.
 
Aug 17, 2008 at 10:47 AM Post #1,375 of 1,562
Quote:

Originally Posted by Heady /img/forum/go_quote.gif
I have an AlienDAC which I built quite a while ago and have been using regularly. I loaned it to a friend and it stopped working when he has it. I found that there is now no output from the adjustable voltage regulator.

Is it possible for the adj voltage regulator to get damaged when the 3.3V regulator is fine?

Is there anyway to find out if the adj voltage regulator is damaged?

Thanks.



5V reg is in no way dependent on 3.3V reg. If 3.3V is OK, your 5V is doing something funky. Just check on the input and output of that reg to check proper voltage.

First though, check that it's installed properly in the correct direction and without solder bridges or cold joints. Check if it gets hot as well.
 
Aug 17, 2008 at 12:26 PM Post #1,376 of 1,562
Quote:

Originally Posted by FallenAngel /img/forum/go_quote.gif
5V reg is in no way dependent on 3.3V reg. If 3.3V is OK, your 5V is doing something funky. Just check on the input and output of that reg to check proper voltage.

First though, check that it's installed properly in the correct direction and without solder bridges or cold joints. Check if it gets hot as well.



Thanks. I know the 3.3V reg is not dependent on the 5V reg. What I meant to say is, if there were some anomaly with the USB power, both would have been affected. But since only the 5V reg is affected, what could possibly be the reason for the failure.

The DAC worked for more than 6 months now, before this happened.
 
Aug 19, 2008 at 4:30 AM Post #1,377 of 1,562
Any of you guys happen to have a spare REG101UA-A and REG101UA-33 by any chance or know of where I can get some? All the major suppliers look like they're out.
 
Aug 19, 2008 at 11:50 AM Post #1,378 of 1,562
Quote:

Originally Posted by a1rocketpilot /img/forum/go_quote.gif
Any of you guys happen to have a spare REG101UA-A and REG101UA-33 by any chance or know of where I can get some? All the major suppliers look like they're out.


I'd try Jeff Rossel, first. You are correct that they don't appear to be available anywhere else.

Alternatively, if you haven't built one yet, there's this version of a PCM2702-based DAC that's pretty close to production:
http://www.head-fi.org/forums/f6/com...layout-190876/
 
Aug 19, 2008 at 5:54 PM Post #1,379 of 1,562
Quote:

Originally Posted by a1rocketpilot /img/forum/go_quote.gif
Any of you guys happen to have a spare REG101UA-A and REG101UA-33 by any chance or know of where I can get some? All the major suppliers look like they're out.



I have a few......
 
Aug 20, 2008 at 9:20 PM Post #1,380 of 1,562
I've been using an Alien that was built by someone else but has recently given up the ghost...in only one of the channels. Is there a set of troubleshooting steps I can follow?
Its been used as a portable DAC, so has seen a fair few bumps. It also has a pair of MCaps as the output, they're rated for like line voltage (off the top of my head) so I would be surprised if its them but could they be the fault?
Also, a potentially dumb question but if my amp has DC protection, do I need the output caps?
 

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