Asus Xonar DX Mods!
Oct 11, 2009 at 12:03 AM Post #62 of 117
Most quality SS amps don't have any kind of DC blocking built in and assume that your source is not putting out DC. I'd never recommend bypassing DC blocking caps on your source.
The caps are Solen MKP

Right after switching I felt it sounded a little nicer than the black gates. But it's really hard to quantify that kind of thing. Anyways, in its current state the card sounds very nice.
 
Oct 11, 2009 at 2:44 AM Post #63 of 117
You have to check with a DMM to make sure the source is not putting out any DC. I said in the last post it depends on what your using next in the chain.

I thought those maybe solens. I have never used them so I wasn't sure.

Did you upgrade the opamps also?
 
Oct 11, 2009 at 5:17 AM Post #64 of 117
Quote:

Originally Posted by rds /img/forum/go_quote.gif
Most quality SS amps don't have any kind of DC blocking built in and assume that your source is not putting out DC.


Where did you hear this?
 
Jan 15, 2010 at 7:56 PM Post #67 of 117
Any advice on replacing the 4580s and 5532 for the front panel connectors?

I tried replacing the 4580s with LME49722 but somehow or another it seems they are unstable in that position. (hearing noise in headphones)
I tried the AD8620 in the 4580 position as well since I noticed the LME49722 is not unity gain stable but I'm still hearing noise...

One odd behavior I have noted is that I hear extra noise in my headphones when my computer is active; for example when I scroll though this page with my mouse, copy a file to a USB flash drive, or there is hard drive activity I can hear extra noise in my headphones (interference from motherboard causing ringing ???)
Besides the annoying noise floor headphone audio sounds quite good through modded Xonar front panel connections though...
Any ideas for troubleshooting?


EDIT: nvm I think my front panel audio is just noisy in general from PSU noise and such...I guess I'll try to shield the front panel audio cable or something...


EDIT: Yay weird fuzzy noises are gone once I got myself a nice shielded cable: FRONTX - Bulkhead/panel mount Headphone & Microphone - supports Intel AC 97 audio header/pinout
So my Xonar is now officially working with AD8620 or LME49722 in all opamp positions. I basically have AD8620s in all front channel audio positions, and LME49722 in the side and rear positions. Also got 1200uF Nichicons on the power. Sounds great!
 
Feb 2, 2010 at 4:50 PM Post #69 of 117
I have a Xonar DX coming soon and would like to change the 2 channel output opamp with a LME49860MA that I have spare here. Can someone confirm the red opamp is the correct one to change?

Quote:

Originally Posted by Yangorang /img/forum/go_quote.gif
Nice little guide there. I think the Xonar is a great card and it's just even greater with a few simple mods.

Here's a little diagram:
xonar.jpg

RED - Front 2 channels
BLU - Surround channels
GRN - Front panel audio I think...

I've replaced the RED and BLU 5532s with LME49722 op-amps and I think it works pretty well.

Added in some 2200uF power supply caps from Nichicon and the bass response is certainly improved.



 
Feb 5, 2010 at 1:04 PM Post #72 of 117
Just successfully changed the opamp with a LME49860MA and it sounds great
smily_headphones1.gif
There was also a little interference at very high volumes which has now disappeared. I also put 2 470uF Panny FMs on the floppy connector input.

Thanks for all the pics and info to help me along. I think I might change out the coupling caps next. I just need to see what rswww has available
 
Feb 5, 2010 at 5:47 PM Post #73 of 117
You can just bypass the coupling caps altogether as they are never good for the sound but in some cases they are a " necessary evil"
If you bypass then you will have to measure for DC as they are there to block any DC but provided the DC is negligable they can be bypassed.
In many cases they are redundant also as the input on your next device my have them also.
 
Feb 6, 2010 at 5:00 AM Post #74 of 117
The circuit has output caps because it is implemented in a way that requires them. Just because you don't measure DC doesn't mean there'll never be DC.
Only bypass them if you're ok with potentially frying your headphones and/or speakers.
 
Feb 6, 2010 at 11:53 PM Post #75 of 117
Hmm, I have seen many sources modified in this way and never heard of them suddenly developing a large DC problem when there wasn't one previously. It doesn't work like that....

Not sure how the card would fry your speaker or phones in any case as you would obviously have an amplifier in between and many modern amplifier receivers, etc will usually have coupling caps on the inputs stopping and DC issue that suddenly develops. However, I have never heard of this happening to anybody...I guess you have?
 

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