Hotrodding the X-Fi: A Layman's Guide (No 56k)
Apr 26, 2007 at 10:46 AM Post #511 of 2,194
Anyone know good replacement for input opamp (M33078) ?
Btw can someone explain to me (like to 5 year old since my english ait too good) what are those 22uf decoupling caps for exacly? (the ones that are reccomended to be shorted). Little schematic would be great and would help me understand it much better.
 
Apr 26, 2007 at 10:53 AM Post #512 of 2,194
Quote:

Originally Posted by LeonvB /img/forum/go_quote.gif
It isn't an assumption. While it's true that a higher capacity will lead to higher ESR (more leakage), the blackgates have lower leakage than other caps. In fact, to stay in range, you'd have to replace it with about 10x the capacity when compared to the original. Surprise, surprise... this is the originally recommended value for the mod.


That is true for the most part, although it's not only about possible leakage but also whether the cards power circuitry can deal with such a big capacity. But there is indeed not really a clear reason why it shouldn't, but it's possible.

Quote:

Correct. You'll have to check all the specs of the opamp. Assuming it's ok just because it has the same pin out isn't smart. Some opamps need higher capacity coupling caps, so beware.


Yeah. And the OP probably did do research on it, for me personally it's hard to see for sure, there are definite character differences between the two opamps involved, but I lack the background knowledge to conclude the level of interchangeability.

Quote:

Lol. Any of the blackgate types beat the original cap. Plus your not in the audio circuit, your in the power supply section. About the only reason to use polar there would be to use 2, to eliminate noise (in a configuration as described on the blackgate pages). But given the environment (a PC), space restrictions etc. I see no need for that particular configuration.


This is true also. The jamicons are not hard to improve on though
smily_headphones1.gif
For power cap indeed regular blackgate would already be a good improvement. For the coupling caps I still would advise nonpolars, also they dont have to be 4x22uF, I'm using 2x10uF instead at the moment (NP) (experimental setup for now). Having said that, if budget isnt too tight then nonpolars are better performers allround.

I'm sorry if I sounded a bit like a smartass in my initial post. Reading it back I mightve had a bit too much coffee that day
rolleyes.gif
but most of it is still valid, just a bit overstated in some regards.

Another thing I want to stress to people who have had some channel fallout problems and L/R balance issues, and something to take care of for those who plan to do this mod: take good care to tin each chip leg well, and if you used copperwick to clean up excess tin, always re-lick that leg afterwards, it is not unthinkable to suck out so much tin that there is no solid connection anymore.
I felt like mentioning this cause the how-to site i linked to early on in this thread may leave the impression you can just tin up then copperwick it and then its fine. But make sure each leg is properly tinned to the connector.
 
Apr 26, 2007 at 2:41 PM Post #513 of 2,194
Quote:

Originally Posted by qwerty009 /img/forum/go_quote.gif
Anyone know good replacement for input opamp (M33078) ?
Btw can someone explain to me (like to 5 year old since my english ait too good) what are those 22uf decoupling caps for exacly? (the ones that are reccomended to be shorted). Little schematic would be great and would help me understand it much better.



they are coupling caps. they are put between the DAC and opamps.
 
Apr 26, 2007 at 6:10 PM Post #514 of 2,194
Received the opamp LM4562MA yesterday (only mod I will do is replace the opamp), is there anything else I should know? or could I get a few tips before I start soldering?
 
Apr 26, 2007 at 6:23 PM Post #515 of 2,194
Quote:

Originally Posted by Inzane /img/forum/go_quote.gif
Received the opamp LM4562MA yesterday (only mod I will do is replace the opamp), is there anything else I should know? or could I get a few tips before I start soldering?


You should probably read this thread in its entirety, to make sure you know the proper techniques.
 
Apr 26, 2007 at 6:30 PM Post #516 of 2,194
Quote:

Yeah. And the OP probably did do research on it, for me personally it's hard to see for sure, there are definite character differences between the two opamps involved, but I lack the background knowledge to conclude the level of interchangeability.


Ok, I've looked at the data.

Input voltage is matched, pins are matched, output voltage is almost matched (LM4562 a little higher), LM4562 itself uses a little more power (few mA).
On the plus side:
LM4562 has 20V/us slew rate vs 3V/us of the old opamp. Distortion, noise rejection, etc.: it's all better. BUT...
On the minus side:
LM4562 is capable of delivering 23mA, while the old opamp can do 70mA. Also, the old opamp can handle low resistance loads better than the LM4562 (though it does lead to higher distortion).

The NJM4556 is specificly made for directly driving headphones, while the LM4562 is the better "preamp". My conclusion: it's close enough to use as a drop-in replacement, provided you know what you're doing. If you want to plug in your headphone without amplification, it's possible the original opamp is a better choice.
 
Apr 26, 2007 at 7:45 PM Post #518 of 2,194
Quote:

Originally Posted by kirimaru /img/forum/go_quote.gif
can someone please tell how long i have to burn in my blackgate nx for the optimal sonic improvement?
should i burn in everytime when i turn on my pc? or just the first time?



i heard some very strange things about the nonpolar blackgates that do not apply to standard blackgates. they say burn-in requires thousands of hours, and prior to that the capacitance is all screwy and it doesn't even act like a capacitor should. if you don't power the capacitor for a few months, you have to start burn-in from the very beginning. i wonder if this is true. i encourage people to try them, though.
 
Apr 26, 2007 at 8:09 PM Post #519 of 2,194
Quote:

Originally Posted by cotdt /img/forum/go_quote.gif
i heard some very strange things about the nonpolar blackgates that do not apply to standard blackgates. they say burn-in requires thousands of hours, and prior to that the capacitance is all screwy and it doesn't even act like a capacitor should. if you don't power the capacitor for a few months, you have to start burn-in from the very beginning. i wonder if this is true. i encourage people to try them, though.


what do you mean that the nonpolar doesnt act like a cap? is it bad or good?
thousands of hours
basshead.gif
? do you think that is worth to wait too long and do you notice the sonic improvment gradually or after certain time?
 
Apr 26, 2007 at 8:11 PM Post #520 of 2,194
Quote:

Originally Posted by kirimaru /img/forum/go_quote.gif
what do you mean that the nonpolar doesnt act like a cap? is it bad or good?
thousands of hours
basshead.gif
? do you think that is worth to wait too long and do you notice the sonic improvment gradually or after certain time?



nah, they're just rumors. just try it for yourself. i've only used the polar blackgates due to size issues.
 
Apr 26, 2007 at 8:42 PM Post #522 of 2,194
Quote:

Originally Posted by kirimaru /img/forum/go_quote.gif
well, the thing is that if i dont hear deference after 2 weeks,then i will try with other caps,and i am going to order nichicon kg gold,kz muse,elna silmic 2 and few others for the psu of my pc.


interesting idea. just be sure to fully discharge the large capacitors before removing them. A 10K resistor would work.
 
Apr 26, 2007 at 9:45 PM Post #523 of 2,194
Quote:

Originally Posted by cotdt /img/forum/go_quote.gif
i heard some very strange things about the nonpolar blackgates that do not apply to standard blackgates. they say burn-in requires thousands of hours, and prior to that the capacitance is all screwy and it doesn't even act like a capacitor should. if you don't power the capacitor for a few months, you have to start burn-in from the very beginning. i wonder if this is true. i encourage people to try them, though.


I would not be surprised.. I have had some *freaky* variances in sound with new nonpolar BG's.. The first hours it literally sounds as if a thick blanket is put over the speakers (and im not talking audiophile-ear detail, it literally sounds as if youre playing through only subwoofers, this slowly faded). Also volume going up and down, etc. The first day orso it sounds very messed up, from then on the blankets fade away and the sound evens out to just right.
I have heard this is one of the reasons (besides price, size) that they are almost only used in custom jobs not production: it takes weeks before the unit will sound as it should.
The extreme varying sound and volume make me believe it if you'd say it doesnt live up to its specs by a long shot, until its settled in a while. But the final result is worth it.
 
Apr 26, 2007 at 11:02 PM Post #524 of 2,194
well,for those who dont want to try or buy the ers sheet,there is a another very simple way to shield your card.
the alternative is to use a "static bag",yes static bag which come with your pc hardware.bcause some of these bags are also made to shield the hardware from emi and rfi.
i am using static bag instead of ers sheet(overpriced).
when i aplied the staticbag to my card,the sonic improvment was significant
the trebels was more clear,tranparent and detailed.
the bass,i couldnt believe what i was hearing,i was able to hear very low frecuency bass notes in the music,bass was more clear and with more depth ,not like the muddy bass of the stock xfi.
guys you should try it,your are not going to loose anything and its just take 5 minuts.
 
Apr 27, 2007 at 12:10 AM Post #525 of 2,194
Did the 1000uF 16V polar blackgate today in my X-Fi Elite Pro and shorted the four caps according this link:

http://www.avsforum.com/avs-vb/attac...chmentid=78157

and I got No Sound
blink.gif
, I resolder the four shorted caps back to the card and the sound restored , so the picture in the link above is not applicable so I decide to not short any caps I' wont do any mod at after installing blackgate.
I appreciate the SVM feature used in X-Fi very much which one of the best implementation features combined with superb SRC it helps to get a very comfortable listening volume level by moderating the dynamics of sound.
smily_headphones1.gif


Anyway Great Mod cotdt
smily_headphones1.gif
 

Users who are viewing this thread

Back
Top