O2 AMP + ODAC

[raoultrifan]

It looks great, now you need to find a way to fit all these opamps inside the original case. Maybe 90 degrees angled adaptor for the SS V5 opamp? You should leave the SS V5 in VAS, as I really don't think V5i would sound better than SS V5, at least not in this scenario.
 
Also, max. power output would be a little bit lower with V5i in buffer stage, at least when low-impedance headphones are be used.

 

[WilliamLeonhart]

Pardon my very limited knowledge on this, but how would I know which opamp will be more suitable for low/high impedance headphones? And while we're at it, how will sensitivity factor in this?

 

[thuNDa]

hey guys, don't wanna hold back this mod i did to my O2(desktop version).

 
It's a meier crossfeed filter with bypass and high/low switch:
 

 

 
 
I mainly use the "high" setting, which brings relaxed listening to another level, even with 60's stereo recordings.

 

[MrMateoHead]

Still no solution to my crackling, distorting ODAC
 
After the problem had gone away for a brief period, it returned with a vengeance. I did a round of driver deletions / updating and nothing is working.
 
Is there a reason that Windows 10 should have broken my ODAC, or is it possible the thing is failing?
 
I did notice that a Driver for Intel(R) USB 3.0 eXtensible Host Controller 1.0 (MSFT) was installed on 3/28/2016. It is version 10.0.10586.212. I can't roll the driver back, and re-installing it did not help. I have a feeling this "automatic update" might've been my culprit. 
 
I could use some help - I miss my ODAC!

 

[raoultrifan]

Pardon my very limited knowledge on this, but how would I know which opamp will be more suitable for low/high impedance headphones? And while we're at it, how will sensitivity factor in this?

The original NJR/JRC4556 opamps can deal with 150mA per channel while being paralleled. If you don't intend to use 32-50 ohms planar headphones you should be fine with the V5i in output buffer stage. Anyway, it worth checking if V5i opamps are warm or hot after 1-2 hours of intensive listening.

 

[WilliamLeonhart]

All of my headphones are dynamic. So far I have not found any problems with the v5i serving as buffers. However it's worth noting that when no headphones are connected to the amp and it's on, the two opamps would heat up dramatically.

 

[raoultrifan]

Get a scope and check for oscillations, O2's designer stated on his blog that some opamps may oscillate. If you can't get a scope I suggest you to replace V5i from output buffer with original 4556 opamps and keep the SS V5 dual in VAS.

I've tested myself with a scope the SS V5 dual in VAS and I had no oscillations; also, sound was more detailed and more spacious.

 

[cityle]

I don't have any problem on my side with Windows 10. But did you tried to switch the usb cable of place betweens usb 3.0 and 2.0 usb ports?

 

[MrMateoHead]

  I don't have any problem on my side with Windows 10. But did you tried to switch the usb cable of place betweens usb 3.0 and 2.0 usb ports?

Ya - The problem follows all the ports, 2.0 to 3.0. I've tried different USB cables as well.
 
A recent update by Windows brought the version of the USB host to (Intel) 10.0.14393.0
 
I had tried the ODAC on a different computer with the same result. I has performed flawlessly until recently. Only the L Channel seems affected. Do these things ever fail or something? Mine is only about 2 years old.

 

[adydula]

I would think the ODAC would last for a very long time....but stuff happens...would have to be some kind of voltage surge, but thats rare here....if the odac was dropped or some kind of mechanical damage...could be just a bad solder joint that over age if "cracked' might have oxidized and is causing this wierd failure. You need to get a second ODAC to see if it works to rule out anything else for sure...
 
Alex

 

[MrMateoHead]

The only way I can get a second ODAC is to buy a second ODAC, and that would be a last resort.
 
I heard the crackling on a laptop I have kicking around as well, but I will try my brothers to see if I get better luck.

 

[WilliamLeonhart]

I sold my first ODAC to a fellow local audiophile and the first thing he did was to break the black thingy on the lower right in the picture (that is marked "L100"). Some how a part of it got sliced off. He told me he heard crackling sound as well. 
So accidents can happen and have happened some where. If the crackling was not consistent, I'd suspect it is due to clipping or overflown buffer. But that doesn't seme to be the case in your problem.

 

[tkddans]

  The only way I can get a second ODAC is to buy a second ODAC, and that would be a last resort.
 
I heard the crackling on a laptop I have kicking around as well, but I will try my brothers to see if I get better luck.

Do you think it's a usb connection issue? What if you tried Schiit's Wyrd? $100 is a pretty steep price to pay for troubleshooting a $250 device, but you can return the Wyrd within 15 days or keep it anyway since it can help prevent future USB issues if they come up.
 
And some people claim Wyrd improves the sound, I guess. I have one and don't notice a difference but oh well.

 

[jseaber]

  The only way I can get a second ODAC is to buy a second ODAC, and that would be a last resort.
 
I heard the crackling on a laptop I have kicking around as well, but I will try my brothers to see if I get better luck.

 
Sorry in advance if this was already shared earlier. Are you listening to an ODAC, or ODAC RevB?
 
PM your order # and I can help out. The ES9023 is known to fail on up to 1% of the original ODACs, confirmed by ESS Q/C. We've repaired all brought to our attention.

 

[MrMateoHead]

  Do you think it's a usb connection issue? What if you tried Schiit's Wyrd? $100 is a pretty steep price to pay for troubleshooting a $250 device, but you can return the Wyrd within 15 days or keep it anyway since it can help prevent future USB issues if they come up.
 
And some people claim Wyrd improves the sound, I guess. I have one and don't notice a difference but oh well.

 
What baffles me is that the device has worked flawlessly on my computer until after I switched to Win 10, which has been buggy, no doubt (I re-installed Realtek audio and networking after the upgrade as both weren't working).
 
I thought I had "fixed" the problem by deleting / reinstalling the USB driver and I went ahead and attacked some others as well. The problem subsided, and then returned. My laptop recently had a major update and I tried the ODAC on it - exact same issue. Static / noise in the L Channel, which can be drowned out with volume to a point but is always there. Unless I have developed a major USB-Audio specific bug on two computers at approximately the same time, I suspect a hardware fault.