[MisterX]

With your meter in ohms mode measure between the 3.3 volt test pad on the Y2 board and ground. 
If the meter reads very low ohms check the X1 soldering
If the meter is reading high ohms repeat the test for the 4.5 volt test pad.
(sounds like you have a short circuit on the Y2 and it's pulling the PSU/USB-VBUS (5 volt pads) low)

 

[FishHead]

You got it.  Last night I started probing around and found the 3.3 v test was shorted to ground.  I futzed with X1 because my soldering was sloppy.  That did not do it.   Nothing was obvious on main soldering so I pulled the schematic and traced out the 3.3 v pins that were next to a ground.  There it was U5 pin 23 to 24.  A little flux and a brief touch with the iron and we have green lights with sound!
 
I am hearing a little noise floor with my UE Pro 5s during some quiet passages and would like some suggestions.
 
I should get the box this week and will post a picture when finished.
 
As of now yet another y2 lives!

 

[K3cT]

Use external power. 

 

[jdkJake]

Quote:

Use external power. 

That is probably a good suggestion. 
 
What are you using as the input source? USB, optical or coax?
 
Mine is USB-only and I never actually tried it with straight USB power as I built it for external power only. That being said, mine is dead quiet. And I mean DEAD quiet. I was quite impressed. The circuit and implementation is top notch all the way.
 

 

[FishHead]

Input was a(n) USB cable.  Foobar2000 ,FLAC rip using DBpoweramp,  DVD quality output.  I was just testing the guts to see if it would work.  Newark messed up my enclosure order so I am waiting for it before I start to hyperventilate about anything.  
 
I just hooked up again using a Stancore (5v .6A) switching regulated wall wort .  Output 1 definitely has a white noise floor esp when compared to Output 2.   Upon further listening to output 2 it may be my imagination as there is a certain amount of white noise rolling around in my head anyway.  As for Output 1 the noise floor is about as loud as my breathing.  
 
I then tested USB.  Same on both except for the dang windows dong which rattled my noggin.  Ouch!   

 

[Horio]

So I'm running into some problems with my gamma-2.  I am building a single box gamma-2 (sigma25 powered) + CKK3 with a selector switch.  I had the gamma-2 working just fine several months ago when I tested it.  When I ran it off the USB power, it worked just fine.  Now that I have gotten to casing up the build, the gamma2 doesn't seem to be ouputting any sound. 
 
I carefully checked the wiring through the selector switch and into the amp board, and everything seems fine.  The sigma is creating 5V as it should, the 5V test pads show 5V, the 3.3V pad shows 3.3V, and the 4.5V pad shows 4.7V.  When I plug it in via USB, the computer detects it and tries to output it sounds to the gamma-2.  I even tried the coax input via my CD player and still nothing.
 
Could I be having some sort of grounding issue?  Maybe something to do with the NKK switches I used for the DAC input and dac filter selection?
 
I'm really at a loss here.  Any ideas?
 
Here are a few pictures:
 

 

 

 

[Horio]

Seems that a good isoproyl alcohol bath seemed to do the trick!

 

[flexium]

I have a question.
 
What if I plug my 75 watt, 8Ohm speakers into gamma 2? What will happen? no sound because not enough power from gamma 2?
 
The reason I am asking because I bought a pair of bookshelf speakers and I want to test them asap but have no way of testing them yet

 

[amb]

Quote:

I have a question.
 
What if I plug my 75 watt, 8Ohm speakers into gamma 2? What will happen? no sound because not enough power from gamma 2?
 
The reason I am asking because I bought a pair of bookshelf speakers and I want to test them asap but have no way of testing them yet

It will make some sound, but not a heck of a lot before clipping. If your γ2 has the AD8656 in its output buffer rather than the OPA2365 it would be a little better into such a low Z load, but there is only so much it could do.

 

[flexium]

Ooo...you mean I can actually try it without damaging anything?
 
I am not sure what opamp I have. I didn't really read into schematics when I asked Marshall to build it for me. Which one is the standard one?

 

[amb]

Quote:

Ooo...you mean I can actually try it without damaging anything?

Both opamps have output current limiting protection so nothing should be damaged.
 
 
Quote:

I am not sure what opamp I have. I didn't really read into schematics when I asked Marshall to build it for me. Which one is the standard one?

 
There is no "standard" one, both are recommended.  You could open it up to have a look.

 

[flexium]

I think I am supposed to look at U7? 2365A... So it's the better one. Would the anticlipping setting do anything?
 
 
I am having a hard time outputing "bit-perfect" to the dac(through SPDIF) using winamp and ASIO plug-in. Feels like my computer is not detecting the dac at all. 
 
I tried the following setting but winamp won't play. it just keeps on skipping to the next song. 
 

 

[nightanole]

your computer cant detect anything via optical/coax out.  It just sends it out, regardless if anything is connected.  Id work backwards.  Set winamp to wave out, see if you can get anything on spdif out.  To double check asio (guess your running xp) try foobar2000 with it.  I take it you did not make a usb version of the y1?  If you did then its not detected.

 

[flexium]

Quote:

your computer cant detect anything via optical/coax out.  It just sends it out, regardless if anything is connected.  Id work backwards.  Set winamp to wave out, see if you can get anything on spdif out.  To double check asio (guess your running xp) try foobar2000 with it.  I take it you did not make a usb version of the y1?  If you did then its not detected.

Got it but not sure exactly what i did. many thanks

 
 
I thought of a new question regarding dac to speaker problem.
 
What if I go from the 3.5mm jack to speaker? Are all the output connected to U7 or are they separated? From the schematic page, I think the phone jack between RCA connection are coming from U7 and I don't see the front 3.5mm jack. 

 

[amb]

 
Quote:

Originally Posted by flexium
 
I think I am supposed to look at U7? 2365A... So it's the better one. Would the anticlipping setting do anything?

 
OPA2365 and AD8565 are both excellent opamps in this application, I wouldn't necessarily say that the OPA2365 is "better", they're just slightly different and subject to preferences.  The AD8565 has lower output impedance and much more output current capability, so it could drive low-Z loads much more effectively.
 
As far as the anti-clipping switch goes, no, it does not prevent clipping caused by excessive loading at the analog output.  The anti-clipping switch's function is to lower the DAC's volume by 2dB to avoid digital clipping with some recordings.  See the WM8741 datasheet for info.