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Old 21st June 2012, 06:26 AM   #2561
Turbon is offline Turbon  Sweden
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Quote:
Originally Posted by Turbon View Post
Same hiss trough the 3,5mm with another O2. I have a third O2 and my old Pioneer that I will test with tonight.
More about this later.
Thanks Stefan (swalter) there is no hiss with the replacement. I will post the hisser today so you can test it. By itself without the O2 it sounds quite good but as soon it is connected to the O2 and music is playing the hissing is there.

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Old 21st June 2012, 01:55 PM   #2562
tschuss is offline tschuss  United States
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Turbon-

Just to clarify: there's no hiss with the replacement ODAC on any of the three O2 copies you have?

I wasn't sure exactly which part or piece of the puzzle had been replaced.

Glad to hear that it's working now!
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Old 21st June 2012, 03:19 PM   #2563
Turbon is offline Turbon  Sweden
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Actually tschuss I havent tested with more than one O2 yet. I recon that they all work fine with this ODAC since the combo missbehaved in the same way with the original ODAC... Shouldn't that be the case there is some sort of bug that has crept in somewhere in the system. With this I mean that not all BOM's might be the same...

No critisism from my side - these things happens...

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Old 21st June 2012, 07:12 PM   #2564
swalter is offline swalter  Switzerland
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Good to hear that the hiss is gone and you are finally able to enjoy your combo!

Stefan
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Old 22nd June 2012, 12:04 PM   #2565
Splatem is offline Splatem  New Zealand
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I successfully built a couple of O2 amps previously, but I am having trouble with two new ones I've just built. Both of the new boards are sending +11.08V of DC output through the headphone jack on both L and R channels. I have checked and double checked the resistances, and looked for any solder shorts with a magnifier. I can't see what I've done wrong, and hope someone can provide some tips to narrow down the problem. I am seeing the same behaviour on both new boards, which makes it seem unlikely that the op amps are all faulty or damaged.

I followed the troubleshooting guide on the nwavguy o2 page, and both boards pass all the steps up until I add the op amps in step 21. When U2 is installed (U1/U3/U4 are not installed) it all looks good, the power rails are +/- 11.7V, U2 pin 7 is +8.4V, U3/U4 pin 4 is -11.7V, and U3/U4 pin 8 is +11.7V. As soon as I install any one or all of the three op amps (U1, U3 or U4), the voltage on U2 pin 7 becomes -11V, and U3/U4 pin 4 becomes +8.7V, with U3/U4 pin 8 remaining +11.7V. Thanks in advance for any suggestions.
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Old 22nd June 2012, 03:38 PM   #2566
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@Splatem - obvious, I know, but have you double-checked the orientation of the sockets, and of the op-amps in the sockets? It's dead easy to accidentally fit one backwards!
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Old 22nd June 2012, 07:45 PM   #2567
Splatem is offline Splatem  New Zealand
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The dot on each op amp is on the side closest to the batteries, matching the white dots on the pcb.
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Old 22nd June 2012, 07:52 PM   #2568
studeb is offline studeb  United States
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try some opamps from a working build
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Old 22nd June 2012, 07:58 PM   #2569
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Also check the sockets are the right way around. One of mine isn't. I know, I know. Somebody
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Old 23rd June 2012, 01:21 AM   #2570
Splatem is offline Splatem  New Zealand
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In addition to 11.1 V on each of the output audio channels, I am measuring +9.2 V on each of the input channels, but I just can't figure out what's causing it.
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