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Hotrodding the X-Fi: A Layman's Guide (No 56k) - Page 97

post #1441 of 2194
Quote:
Originally Posted by stormcloud View Post
This thread has been most informative, went through all 144 pages and I can tell you sometimes it makes my head spin. That argument on shorting the 22uF coupling caps vs bypassing them especially.

I've got a question for bichu/germanium or anyone else that can shed some light into it :

Based on general opinion, electrolytic caps are bad for coupling in the direct signal path. Assuming there is a DC offset and one rules in favour against shorting/forming a wire bridge, would a straight forward replacement of those 22uF electrolytic caps with a polyester or polypropylene (values between 0.47uF - 1.5uF) work?
As the other poster have stated, you may lose a lot of lower ends, but in either cases, it is not fun to have a pair (or 3~4 pairs) of high quality PP caps dangling on your sound card. It will definitely take out an additional slot or two by simply blocking the slots for other expansion cards.


If you are *REALLY* afraid of the DC bias, here's something you can do.

Short the onboard coupling caps, yes I know what you are thinking, but there's more.

Pick a external enclosure of your liking that is capable of housing the number of capacitor that you need. (1 pair or 4 pairs, whichever you prefer)

Wire the output of your sound card to the box and hook up the capacitor as follows:

Input -> 100K Resistor to ground
Input -> 1uF Capacitor -> Cap output
Cap output -> 100K Resistor to ground
Cap output -> Output connector on the box.

Yay~~~ You got yourself an external capacitor coupling box... I haven't really calculate the low frequency dropoff point, but IIRC it should be quite low.


You should wire some sort of cable to hook onto your sound card's standard output connector, instead of directly onto the PCB. Just for the sake of safety and reliability.


The cap coupling box is also useful in cases where you are uncertain if there are going to to be DC bias in the output. This can be a useful "insurance" if you are modding and unsure if it will blow up in your face after 10 minutes of run-ins. :P
post #1442 of 2194
Quote:
Originally Posted by stormcloud View Post
This thread has been most informative, went through all 144 pages and I can tell you sometimes it makes my head spin. That argument on shorting the 22uF coupling caps vs bypassing them especially.
I've got a question for bichu/germanium or anyone else that can shed some light into it :
Based on general opinion, electrolytic caps are bad for coupling in the direct signal path. Assuming there is a DC offset and one rules in favour against shorting/forming a wire bridge, would a straight forward replacement of those 22uF electrolytic caps with a polyester or polypropylene (values between 0.47uF - 1.5uF) work?
Quote:
Originally Posted by stormcloud View Post
Thanks for that confirmation. It's been a long time from the EE I took at university, I'm just slowly getting back into the scene. Re-learning all this back is fairly exciting. It's perverse, I used to hate analog/power electronics

So it looks like I'm pretty much stuck to 22uF (or higher till 220uF) value for a straight forward replacement. Loosely basing the freq response on the simple high pass filter below :

f = 1 / 2 * 3.1415 * R * C
f = low freq cut-off (at 3dB)
R = sum of impedance
C = coupling capacitance
- am I correct to assume that bypassing generally decreases impedance, increases the low feq cut-off, but gives you a (freq dependent) better mid-range and high-end?
- any good suggestions for decent polyester/polypropylene caps 22uF - 220uF?
- if using electrolytic cap, it's obvious that super low ESR caps like the OSCON offers better benefit than the standard cap
--------------------
updated :
Went back and trawled to post #1312 from bichi. Looks like 33uF is a good value.
Looks like most (if not all) poly caps with the above sort of value are either uneconomical or simply too big a monster to mount on the X-Fi or both. I guess Blackgate N/NX bipolar is the next best bet ... oh well ..... gosh ... did I just answer my own questions? lol

stormcloud,
- yep, you may have answered your own questions...
- assuming you don't want to hang large film-type caps, electrolytics, tantalums, MLCC (X7R, NPO) are not as bad as most think.
- since you mention 22uf coupling cap, I assume you have a SB0460.
- generally, lower the coupling cap value, less LF/bass response.
- correct, 33uf seems to be the optimal value with Panasonic "S" SMT capacitors, for my playback system and tastes.
- might consider socketing and trying different types, adjusting value/type to your personal tastes.
- agreed, good quality "non-polar" might be worth a try.
- I would not rule out tantalum or MLCC X7R capacitor types, regardless of conventional thinking about coupling-caps types.
- beware it is a differential 2-pole active low-pass filter, after the DAC, and simple static formulas may not be appropriate.
- you also mention taking university EE and might be interested in simulators, which allow easy modeling, relative to performance.
- (links below)
- SB0460 use small components, difficult to trace, determine values with parts "in-circuit" and load into a simulator.

I purchased Germanium's blown card (SB0550), have traced the differential 2-pole LPF circuit.
- parts are larger and SMT resistor values are labeled.
- configured circuit for Texas Instruments TINA simulator. (*.TSC file, and TINA simulator, links below)
- might be of interest to install TINA and play with coupling cap values and see how they affect frequency response, noise, S/N, etc. (painless, push-button AC/DC, Bode, FFT analysis compared to the old days)
- Texas Instruments Active Filter Design, FilterPro is another "fun" application to play with.
- have experimented with tantalum and currently playing with MLCC caps, X7R, 22uf 16vdc (high volumetric efficiency)
- will post MLCC cap results in a week or so...
- results so far: "sounds more like wire, as opposed to a capacitor..."
- TDK MLCC, SMT, PN: C3225X7R1C226M; 22uf @ 16vdc (might want to give these a go on your SB0460)
- added: Wolfson coupling cap and AVX tant vs. MLCC whitepaper links


REF:
Texas Instruments TINA v7.0:
SPICE-Based Analog Simulation Program - TINA-TI - TI Tool Folder

SB0550 2-Pole Active LPF Circuit File for TI TINA v7.0:
X-FI-MOD-097b - eSnips, share anything

Texas Instruments Active Filter Design, FilterPro:
Active Filter Design Application - FILTERPRO - TI Software Folder

TDK, MLCC, PN: C3225X7R1C226M; 22uf @ 16vdc @ Mouser:
http://www.mouser.com/catalog/631/679.pdf


Added REFs:
Recommended Output Filters for Wolfson Audio DACs:
http://www.wolfsonmicro.com/uploads/...en/WAN0171.pdf

Comparison of MLCC and Tantalum Capacitors:
http://www.avxcorp.com/docs/techinfo/mlc-tant.pdf
post #1443 of 2194
It is amazing what cotd and I started. I can't believe this thread has gone on so long and has gotten so detailed. From something that started with a PM saying hey I can make your X-fi sound better to 144 pages later allot has been learned! Keep it up guys. I really want to buy a new card just to try the newest additions to the mods.
post #1444 of 2194
Wow! Why didn't I read this before buying my 0404??? I am definitely going to try this on my X-Fi platinum especially since its not under warranty anymore!
post #1445 of 2194
edit- fixed my problem
post #1446 of 2194
Blackgate's are no longer in production according to percyaudio. Are there any alternatives? Can someone provide a link to an alternative?
post #1447 of 2194
I just soldered on the new LM4562 and when I put it back into my computer I had no sound at all. From what I can see there is no excess solder and none of the leads are touching. Is there anything I can test or do? I used a multimeter to test for resistance between each leg and the pci connector.
post #1448 of 2194
Quote:
Originally Posted by Vandal View Post
Blackgate's are no longer in production according to percyaudio. Are there any alternatives? Can someone provide a link to an alternative?

Rubycon za/zl series are good caps as a substitute.
post #1449 of 2194
Whoops wrong thread.
post #1450 of 2194
Quote:
Originally Posted by Vandal View Post
Blackgate's are no longer in production according to percyaudio. Are there any alternatives? Can someone provide a link to an alternative?
Panasonic FM series are almost the standard for power caps in DIY amp building. Cheap, easy to find and sound good.
post #1451 of 2194

coupling caps

I was trying to read every post but I was not able to come to a conclusion on whether to short or decouple the caps (not really sure if I am using the correct terminology).
I do not really have any background in electronics but the idea of modifying my x-fi to greatness really sounds good to me.
I can not remember if it was bichi that posted that exchanging this with 33µF 16V caps instead of shorting the four would be almost as good as shorting.
I also read the forum from overclock.net and soloz2 also votes to exhcange the caps with a better replacement as an alternative to shorting. And in turn help do without the dc offset, which might endanger the audio equipment.
I do understand that if I'm after great SQ it should be shorted but I would want my equipment safe.

The capacitors soloz2 used, in one of the mods he made for someone else, are 22µF but they are 25V which is far from the original voltage of the caps to be replaced.

I'm planning to use those Nichicon KG

My questions are:

What is the diameter of the caps he used wherein he (Soloz2) said its a tight fit (but nonetheless a good fit IMO) when he replaced all 16 caps?

Which is better, as a replacement for the 16 caps a 33µF 16V or a 22µF 25V, in sound quality and would not increase the DC offset (bias <--not really sure which is which offset or bias)?

When you have someone in Japan to buy good capacitors for you which would be best suited for this mod? I am considering nichicon KG and am eyeing the 33µF 16V for the 16 coupling caps. The reason I want my friend to buy it when she visits there is because I don't trust the electronic part stores here in the Philippines, there's so much counterfeit stuff, I might pay a premium and still get a crappy part. What was funny was there are Rubycons displayed and another that's named Robicon a rather devious ploy for those who were told by word of mouth that Rubycon is the best then they would buy Robicon and mistake it for the other. I still don't trust the Rubycons that are displayed though.

PS
Soloz2 and Bichi
I need your help fast she'll be leaving at the 13th I need to instruct her and research the parts needed before I send her to buy me some of those great stuff.
post #1452 of 2194
Thanks a lot for this cotdt and everyone who helped contribute. I modded my X-Fi Platinum Fatality with the 2200uF blackgate and the 4562. Even slapped the ERS paper on the back of the card. I'll have to say, the ERS paper did solve this problem I was getting in regards to noise. I guess it was because I have an 8800GTS sitting right above it just throwing interference at it. With the ERS paper there is ZERO noise like I was getting before intermittently. And I agree that it is a slightly warmer sound. I did this mod seperately before I had the parts soldered on.

With the 4562 and Blackgate I think the sound is more crisp and seems to have a smooth flow. Fatigue on the ears seems to be much less. All in all I'm very impressed with how much this card has improved.

FYI I am using this with a MisterX XP amp to a pair of DT770-80s. Beautiful setup to say the least.
post #1453 of 2194
Quote:
Originally Posted by borgsm1 View Post

1) "...I can not remember if it was bichi that posted that exchanging this with 33µF 16V caps instead of shorting the four would be almost as good as shorting...."

My questions are:
2) What is the diameter of the caps he used wherein he (Soloz2) said its a tight fit (but nonetheless a good fit IMO) when he replaced all 16 caps?

3) Which is better, as a replacement for the 16 caps a 33µF 16V or a 22µF 25V, in sound quality and would not increase the DC offset (bias <--not really sure which is which offset or bias)?

4) When you have someone in Japan to buy good capacitors for you which would be best suited for this mod? I am considering nichicon KG and am eyeing the 33µF 16V for the 16 coupling caps. The reason I want my friend to buy it when she visits there is because I don't trust the electronic part stores here in the Philippines, there's so much counterfeit stuff, I might pay a premium and still get a crappy part. What was funny was there are Rubycons displayed and another that's named Robicon a rather devious ploy for those who were told by word of mouth that Rubycon is the best then they would buy Robicon and mistake it for the other. I still don't trust the Rubycons that are displayed though.

PS
Soloz2 and Bichi
I need your help fast she'll be leaving at the 13th I need to instruct her and research the parts needed before I send her to buy me some of those great stuff.
**************

I assume you have a SB0460 (X-FI, Music, Fatality, etc.) and not a SB0550. (Elite Pro)
Have not included specialty caps, Blackgate, Muse, Prizm, etc., since I don't have direct experience with those brands.

1) Right, not the same as shorting, but closer. Arrived at 33uf value from experimentation and tests. You can see small RMAA deviations, but nothing thats "WOWIE!.." See pic link:
X-FI-MOD-073b - eSnips, share anything

2) You can see from pictures, Panasonic 33uf SMT parts I used are "tight" and would not fit if mounted directly. Since I socketed, I could offset centers via carriers. Guessing 5mm diameter parts would be the "max" for direct installation.

Original: Jamicon SS, 22uf @ 16vdc (4.2mm d)
Replacement: Panasonic S, SMT, 33uf @ 16vdc (6.3mm d)

Reference Pictures:
X-FI-MOD-055b - eSnips, share anything
X-FI-MOD-058b - eSnips, share anything

Panasonic S, SMT Datasheet:
http://industrial.panasonic.com/www-...ABA0000CE2.pdf

3) Generally, capacitor higher voltage ratings are of no consequence, except larger physical size. Some with "very high-end" playback and sources claim better sound characteristics due to size, which is related to ESR/DF and size, and has been argued both ways. (note: never exceed capacitor ratings, however. (example: never install a 6.3vdc rated capacitor in a 12vdc circuit)

4) Not sure what your question is, but a "final" optimized part recommendation is tough and highly subjective. Depends on your listening tastes and playback system. Be aware, even quality electrolytics each have their own distinct "sound signature."

Some claim bi-polar coupling caps are good:
http://industrial.panasonic.com/www-...BA0000CE97.pdf

You might consider replacing power cap C16 with a Panasonic FM or FC, 220uf @ 25vdc, shown in link below. Some claim Panasonic FC's sound too sharp. Power cap C177 (filter for CA20K1) has less sound quality influence.
X-FI-MOD-029b - eSnips, share anything

Note ultra-low ESR caps (ie., OSCON) for C177 may cause ringing in local switching regulator for CA20K1.
X-FI-MOD-064b - eSnips, share anything

Panasonic FC and FM datasheets for part numbers:
http://www.panasonic.com/industrial/...eeu_fc_dne.pdf
http://www.panasonic.com/industrial/...A0000CE108.pdf

Good Luck!

(link to X-FI mod details in sig below)
post #1454 of 2194
Bichi,
Thank you so much for your reply
I suspect that the choice for capacitors will be subjective. I had no prior experience to any of them so would have to trust the opinions those who have had many years spent in listening to the subtle differences in the sound of capacitors.
I would also believe that by replacing the Jamicon, which the general consensus regards as low quality, with a better nichicon caps would be a step up.
I would rather not go with your choice of smt parts because I fear it would be to hard for me of a modification. I am going 33µF 16V Nichicon FG the coupling caps would be considering other capacitors even panasonic fm if she could not find any nichicon FG because I think my friend, who would go to Japan, would have hard time finding anything there.
Thanks for the c16 modification
It might be my lack of experience but I find with my koss spark plug that the original sound of x-fi was kind of dull, and find that the onboard sound of the asus p4p800 more lively. Actually when I plug my koss spark plug in my phone an a780 i find it better than the sound of my x-fi. When I heard my x-fi it was using the driver that came with it. I am using Windows XP SP2 then at work. I haven't tried it again with the plug because I lost it. I now have my x-fi stashed with my other stuff, would use it again after the mods.
Thank you for everyones contribution.
I love the discussion.
post #1455 of 2194
Is their a way I can send my X-Fi Platinum to a guy who already has the parts because I cant really do this myself LOL. That'd be so awesome!
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