Asus Xonar DX Mods!
Feb 5, 2009 at 9:16 PM Post #31 of 117
Quote:

Originally Posted by syllabus /img/forum/go_quote.gif
Really, try the OPA2727. It's a whole new world from the OPA2107, @ 12V.


If I can hunt down a way to get it, i might try it. Elfa which is the main supplier of electronics in sweden does not have it. How does it sound compared to 4562 or the 8620?

EDIT: As the stock electrolytics are 10V, for the 220uF cap, would a cap made for maximum of 6.3V work? Should work out fine, just thought I'd asked if I overlooked anything. I canget the caps for free more or less so I figured it might be worth a shot.
 
Feb 8, 2009 at 10:05 PM Post #32 of 117
Quote:

As the stock electrolytics are 10V, for the 220uF cap, would a cap made for maximum of 6.3V work?


I don't think that's a good idea. I'm not sure exactly what the voltage is coming in through the power cable, but I know the highest voltage rail on a pc power supply is 12V. So I recommend 16V, as it is a common value that is greater than 12V.
Replacing stocks caps with lower voltage ones is a dangerous thing to do unless you are absolutely sure of the wost case scenario.
 
Feb 8, 2009 at 11:16 PM Post #33 of 117
Quote:

Originally Posted by rds /img/forum/go_quote.gif
I don't think that's a good idea. I'm not sure exactly what the voltage is coming in through the power cable, but I know the highest voltage rail on a pc power supply is 12V. So I recommend 16V, as it is a common value that is greater than 12V.
Replacing stocks caps with lower voltage ones is a dangerous thing to do unless you are absolutely sure of the wost case scenario.



The Supplyvoltage from the floppy-connector is +5 and +12V, but what comes across the cap.. I have no idea, but since they're 10V caps (right?) it's should not be 12V? I was not planning on putting it in without knowing for sure. But I figured I'd ask here if you or somebody else had measured. It's common sense not to put a 6.3V cap where a 10V is placed without being sure if it'll go poof or not. (for most people)
biggrin.gif


Normally I'd just grab a 16-25V cap and be done with it, but I got a pair of decent caps for free from a friend yesterday. So that's kind of why I wanted to check before buying something I wouldn't need. I have a multimeter but there is no chance in hell i can reach any measuring points in the cramped case. I'll figure something out and get back to you guys.
 
Mar 6, 2009 at 1:00 AM Post #34 of 117
Ok, done a little research and fiddled a bit with the datasheets. Opamps are being fed 16 Volts, located a few caps (I think) but could not get a measure on the 220uf Caps. Anyways, they're not in the signalchain are they? I've been looking like a maniac through the datasheets for the CS4398 and can by no means find the 220uf Caps in the sheets over the design. No probs finding the 22uF cap and so.. Argh, I sigh at my lack of understanding this circuitry fully a bit. I get that it filters high freq but I don't get why it's actually there but not in the datasheet. Since size decided the freq of the cutoff a slight change in the value of the cap might cause issues if it's in the signalpath I guess.

Anyways, next week I have replacement caps for the 22uF and a new OPamp coming for my modding pleasure..
 
May 17, 2009 at 2:07 AM Post #35 of 117
Sp +8/-8?? Is that measured or directly from datasheet? Any room to hack a dip socket into those SO8 pads?
 
Jul 22, 2009 at 4:38 PM Post #36 of 117
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.
 
Oct 8, 2009 at 11:31 AM Post #38 of 117
Quote:

Originally Posted by rds /img/forum/go_quote.gif
Nice work!
I much prefer the ad8620. It is much more detailed than the stock 5532. Some people might find it too "aggressive".




I have 2ps of AD8620 and 5 of OPA2727. What better to use?
confused_face(1).gif

What are 2 of 5532 and 2 of R4580 under cs4398? Is it good idea to replace them as well?
Thank you for your help.
 
Oct 8, 2009 at 11:39 AM Post #39 of 117
Hi!
Is it possible to add separate optic output if I want to use Line-In and SPDIF at the same time? Can it be connected in parellel to existing connector?
Did anybody try this mod?
 
Oct 8, 2009 at 12:06 PM Post #40 of 117
Quote:

Originally Posted by Vitaliy /img/forum/go_quote.gif
I have 2ps of AD8620 and 5 of OPA2727. What better to use?
confused_face(1).gif

What are 2 of 5532 and 2 of R4580 under cs4398? Is it good idea to replace them as well?
Thank you for your help.



There are many great opamps you could use aslong as they are compatible with the circuit.

Not all opamps are for output some would be buffers for the Mic and line.

The AD8620 is a pretty good opamp for audio.
 
Oct 9, 2009 at 11:48 AM Post #41 of 117
Quote:

Originally Posted by ROBSCIX /img/forum/go_quote.gif
There are many great opamps you could use aslong as they are compatible with the circuit.

Not all opamps are for output some would be buffers for the Mic and line.

The AD8620 is a pretty good opamp for audio.




So were should I put AD8620 and were OPA2727?
I plan to use 8620 for front and central/sub channels. And 2727 for the rest.
Is here reason to replace U4,U5,U7 and U8. Looks like they are for recording. Am I right?
 
Oct 9, 2009 at 12:38 PM Post #42 of 117
I think I should still have a DX in my parts room. Let me have a look at it and post back.

The opamp shoudl be very close to the output for the fronts. This should give you a idea of which one to change for the fronts, center sub..etc.

This is actually a great card for the price, just a shame they didn't put opamps sockets on the card.
I will post more info later after I find and have a look at this card. Unless somebody posts the needed information first.
 
Oct 9, 2009 at 1:48 PM Post #45 of 117
That is the idea to separate LINE/MIC-In and SPDIF-Out.
U4 and U7 is ADC input buffer. Could replacing them with OPA2727 improve recording quality? What function of U5 and U8 (4580). Is it MIC/LINE/AUX-in preamp? Could it be one is preamp when another - mic boost?
 

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