Hotrodding the X-Fi: A Layman's Guide (No 56k)
May 13, 2007 at 12:57 AM Post #706 of 2,194
the legs are easy to solder if your iron is powerful enough. i got this iron for $2, and it got so hot that it can melt solder anywhere. too bad the metal tip of the iron also melted when i left it on for over 10 minutes one day.
 
May 13, 2007 at 2:26 AM Post #707 of 2,194
Yeah they're not too hard to get out if you to it right. But his problem is that he didn't pull it out but cut the legs off, leaving a small bit stuck in there (i did the same, wont happen again
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). If its really stuck, take a precision drill to it. Apparantly seba already succesfully did so.
 
May 13, 2007 at 5:59 AM Post #708 of 2,194
well... what I did is flooded the hole with solder, then apply anther wire through it while it is heated. This will push out the wire in the hole
 
May 13, 2007 at 6:02 AM Post #709 of 2,194
Quote:

Originally Posted by ]|[ GorE /img/forum/go_quote.gif
Eager for the Audio Precision results.


Bah today I tried everything I could think of to get the Digital-In on my X-Fi to work but for some reason it doesn't (I enabled the Digital I/O, and un-muted Digital In in the mixer...looks like there's nothing else I can choose). I read somewhere that the X-Fi Digital In needed +5V digital signals to drive it, so I even hooked up the AP's SPDIF signal to a buffer so it was boosted from 2.5V to 5V...no luck. I was really hoping to be able to drive the X-Fi with the AP so I can make sweeps from 20Hz to 20kHz and produce pretty graphs for everyone to see
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So far, the measurements I made with the AP and a software test tone generator were some THD+N numbers at a few frequencies and a few different volume settings. I also made some FFT plots.

I don't remember all the exact details now but in case some of you are curious, here are some numbers I remember off the top of my head:

X-Fi ExtremeGamer Fatality Before Mod (All effects off, Wave Volume 100%)
1) Entertainment Mode, Lineout @ 1.35V (master vol 85%): THD+N @ 1kHz: -96dB
2) Entertainment Mode, Lineout @ 2.2V (master vol 100%): THD+N @ 1kHz: -94dB
3) Entertainment Mode, Digital Out (master vol @ 85%): THD+N @ 1kHz: -101dB
4) Entertainment Mode, Digital Out (master vol @ 100%): THD+N @ 1kHz: -103dB

* I took the Digital Out numbers just to get a reasonable reference as to what the best result may be without all the analog output circuitry. Looks like even with the lowest distortion opamps and ultra-low noise resistors, the output will hit a wall at around -103dB.

This is just my first round of tests as I get things set up properly. The next time I measure the card I may actually use a realistic headphone load too (the numbers above were taken @ 100K I think set from within the AP). I'll get some more numbers after I change the opamps. However, if anyone knows how to get the Digital In to work on the X-Fi, or if there are suggestions to improve testing, let me know!!!
 
May 13, 2007 at 6:19 AM Post #710 of 2,194
Can you measure the transient intermodulation distortion? The LM4562 is reputed to have much better results than the jelly bean opamps (like the one on the stock X-Fi). As far as THD, all opamps will measure pretty much the same, which is to say extremely good.
 
May 13, 2007 at 6:41 AM Post #711 of 2,194
Quote:

Originally Posted by cotdt /img/forum/go_quote.gif
Can you measure the transient intermodulation distortion? The LM4562 is reputed to have much better results than the jelly bean opamps (like the one on the stock X-Fi). As far as THD, all opamps will measure pretty much the same, which is to say extremely good.


I'm having some problems measuring TIM. I saw some standard IMD and TIM test signals and from the AP software, but without digital-in working on my X-Fi I don't really have a good way to test it. I don't want to use Analog-In on the X-Fi because from what I've measured, it degrades distortion/noise performance by around 6dB (which is a lot when I'm measuring really low level distortions) Also, I've never actually run a TIM test before, so if there are some standards for testing TIM, I'm all ears (or eyes since I can't hear you speak).

Regarding the THD+N performance of opamps, I think at their best settings they're pretty comparable, but depending on the supply rails, output level and load, things change quickly. If you look at the THD curves of the 4556A versus the LM4562 from their datasheets, they're actually quite different.
 
May 13, 2007 at 6:46 AM Post #712 of 2,194
Also, for what it's worth, I recorded some square wave and triangle wave response...so in case I fail horribly at measuring the TIM, at least maybe the response graphs may show some differences between the 4556A and the LM4562.
 
May 13, 2007 at 7:24 PM Post #713 of 2,194
Well, I've got 2 orders coming to me... one was $20 S&H, and one was free
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so $20 for 6x 4562's... can't complain
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Will most probably do the mod to my Audigy2 ZS as well (pending a 3rd order)

Picked up some micro side cutters, flux, and solder wick at work today... already have a variable iron, silver solder, silver conductive pen...

So just have to order the Blackgates now...
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May 14, 2007 at 1:59 PM Post #714 of 2,194
So I love this mod now. I did the anti static bag mod, and it sounded horrible. I started reading how people didnt like it so I took it out and now the sound is wonderful. ALOT NICER. I love it. Absolutely love it.
 
May 14, 2007 at 3:32 PM Post #715 of 2,194
should you replace the input amp if you run dvd player through soundcard? do you replace with same opamp as output?
 
May 15, 2007 at 7:51 AM Post #717 of 2,194
Quote:

Originally Posted by Pm@c /img/forum/go_quote.gif
So I love this mod now. I did the anti static bag mod, and it sounded horrible. I started reading how people didnt like it so I took it out and now the sound is wonderful. ALOT NICER. I love it. Absolutely love it.


Yeah...anti static bug is not a good idea
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May 15, 2007 at 10:41 AM Post #718 of 2,194
Quote:

Originally Posted by soloz2 /img/forum/go_quote.gif
the 24hr samples is where you can order the free samples. You can get a max of 3 and you might have to pay S/H.

I wouldn't advise you do this mod if you don't have much soldering experience. The card acts like a heatsink and is a PITA to solder at times. Also, SOIC op-amps aren't exactly beginners level.



Its funny (because of my situation) but soldering the op-amp was 100x easier than the capacitor (just because I cant get one of the legs out). I havent drilled it out yet cause I was watching the hockey game last night, but hopefully I get to it tonight and get the capacitor properly soldered.
 
May 15, 2007 at 2:59 PM Post #719 of 2,194
yeah, i though capacitor would be easier than the opamp to solder. any advice for capacitor? i ordered op amps and am ordering cap today. this will be my first soldering experience. any advice? also still trying to find out if i should replace input op amp with lm 4562?
 

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