[coolkwc]

Quote:

Originally Posted by Apocalypsee /img/forum/go_quote.gif Planning to buy Sanyo OS-CON for coupling caps, is it recommended? I have 680uF 6.3V OS-CON, but I think the capacitance is too much for coupling, but can I use them anyway?

Ermm, i just soldered 680uf as coupling cap, surprisingly it boost a little in the low region and high region..so far didn't hear any bad effect by using large capacitance cap as coupling cap, so i think it won't be a problem...

 

[yzriver]

I have a X-Fi Platinum with the I/O bay installed in my PC. I just set it up last night, and listened music from the headphone output on the panel. The sound is muddy. Yes, I amplified the headphone output with a headphone amplfier to drive my AKG K501. I feel it is worse than using the XMod.
I am excited to find this thread. I don't care much on the sound quality of the analog line-out, since I will use digital out to my receiver for playing music with speakers.
Could you guys suggest how I can upgrade the headphone output module of this X-Fi Platinum?

thanks a lot.

 

[Random Murderer]

Quote:

Originally Posted by yzriver /img/forum/go_quote.gif I have a X-Fi Platinum with the I/O bay installed in my PC. I just set it up last night, and listened music from the headphone output on the panel. The sound is muddy. Yes, I amplified the headphone output with a headphone amplfier to drive my AKG K501. I feel it is worse than using the XMod. I am excited to find this thread. I don't care much on the sound quality of the analog line-out, since I will use digital out to my receiver for playing music with speakers. Could you guys suggest how I can upgrade the headphone output module of this X-Fi Platinum? thanks a lot.

pictures!
i demand pictures!!!

in all seriousness, we need some shots of the pcb on the bay device and the card.

 

[Apocalypsee]

Quote:

Originally Posted by coolkwc /img/forum/go_quote.gif Ermm, i just soldered 680uf as coupling cap, surprisingly it boost a little in the low region and high region..so far didn't hear any bad effect by using large capacitance cap as coupling cap, so i think it won't be a problem...

I've tried it on top of 10uF (the 680uF is big, I can't fit in the holes), it sounds OK. I got a lot better response on lower region, the bass seems fuller now. Might sound a little better too, I heard some details on background that unheard before even on lower bitrate mp3 files. No other ill effects as far as I an heard or tested

 

[coolkwc]

Quote:

Originally Posted by Apocalypsee /img/forum/go_quote.gif I've tried it on top of 10uF (the 680uF is big, I can't fit in the holes), it sounds OK. I got a lot better response on lower region, the bass seems fuller now. Might sound a little better too, I heard some details on background that unheard before even on lower bitrate mp3 files. No other ill effects as far as I an heard or tested

the RMAA test can justified our claim...

you can read here as well..
Input Capacitors for Headphone Amps

 

[trodas]

About the muting transistors.

The shorting of the muting output transistors is interesting idea. I think it is a fair trade to trade the clicks when drivers is loading AND when switching the audio modes for the higher detail level, don't you agree?

However I seen just this image:


That says it bypass them, however there is two main problems.
1) it is only for the L and R channels, while I need to take care about six channels - L, R, RL, RR, CENTER and SUB.
2) tracing the pins of the transistors back to the opamps output (pins 1 and 7) show no connection at all to those shorted pins!

Anyone know where the output from pins 1 and 7 of the opamps really go? The mod definitively connect well the output, but the input is wrong...

And what about the other channels?!

Here is a little drawing of what I checked to be true - X-Fi jacks connection

Any help/ideas? What I did overlook?

 

[catx]

Quote:

Originally Posted by trodas /img/forum/go_quote.gif About the muting transistors. 2) tracing the pins of the transistors back to the opamps output (pins 1 and 7) show no connection at all to those shorted pins!

They are not directly connected, there is also a small resistor in the output path (part of the biasing circuit for transistors?) but it shouldn't affect sound quality.

OPAMP>-[R]->[MUTING]->[jack]

I suppose the circuit is the same for the other channels (the small ICs are just dual transistors in a single package)

 

[bichi]

From an old post, describing effect of coupling-capacitor value and frequency response for the SB0460.
- note largest effect is low-freqency response.
- table shows typical capacitor values, derived from CS4382 DAC, Wolfson WM8775 ADC design/eval notes and acutal measurements.
- additional coupling-capacitor selection data in Wolfson app note below.

Old Post, Sept 22 2007, coupling cap values vs., shorted, RMAA response and graphs:
http://www.head-fi.org/forums/3283113-post1312.html
X-FI-MOD-073b - eSnips, share anything

Table, calculated results:
X-FI-MOD-118-SB0460 Coup Cap - eSnips, share anything

Conclusion:
- point of no or little practical performance increase is about 33~47uf...

REFs:
SB0460
- Cirrus Logic: CS4382 DAC (Zo analog: 3k) (PSRR: 60db @ 1khz) (stock: Jamicon 22uf @ 16vdc)
- Wolfson: WM8775 ADC (Zo analog: 10k app note) (PSRR: 45db) (Stock: WinCap NP 4.7uf @ 16vdc)

Wolfson AC Coupling Capacitor Selection App Note:
http://www.wolfsonmicro.com/uploads/...en/WAN0176.pdf

 

[trodas]

catx - Quote:

there is also a small resistor in the output path (part of the biasing circuit for transistors?) but it shouldn't affect sound quality

Well, it is probably resistor with relatively low value (I say like 100 ohms) to protect the output opamps from shortcut in cable/connectors. It sure does affect the sound quality, but after the opamps we are out of the pre-amp supersensitive stage, so the impact will be very small.
I say keep it there.

Quote:

I suppose the circuit is the same for the other channels (the small ICs are just dual transistors in a single package)

That sounds very logical, thank you. Now how these small dual transistors have their pins connected, so we know what to short?

Regardless, usually the single package transistors has in the single pin side a collector pin. I fail to see how shorting two colectors could bypas the signal over them, but not for long.

If I undertstand this right, then it is necessary to use TWO transistors per channel to get the positive AND the negtive parts of the audio signal thru. So these transistors are about to be in parallel with their collectors and emitors, hence shorting the two collectors do the job.

As you can see, shorting the collectors OR emitors really does the job there. But how with these dual transistors?!




About AD8599 opamp
(testing made my friend, imperialreign, who have tad better ears that me and take music really seriously)

Fatal1ty with LM4562

Fatal1ty with AD8599

I ran the AD8599 tests 4-times each to make sure of those results - comparatively, the AD8599 allows for a better dynamic range at all testing levels, compared to the LM4562... it might only be an average difference of -2dbA, but for such a small component that's a lot...

THD and IMD+N results for the AD8599 are very-slightly better, the most improvement difference, though is at 16bit playbacks; coupled with the slightly higher dynamic range, I'd conclude as well that these OPAMPs aren't as affected by EMI as the LM4562.

Also of note - the AD8599 rated better at stereo crosstalk than the LM4562... meaning there's less channel bleeding.

TBH, the AD8599 sounds the same to me now as it did after first installation (surprisingly). I really also dig how they sound compared to the LM4562 as well; the 4562 OPAMPs produce some very sharp frequencies that I personally found to be annoying at times. The 8599 has a lot warmer sound, IMO it has a lot more depth to it.

For the cheaper price, I'd say it ousts the 4562.

 

[trodas]

Removing X-Fi muting transistors.

Having transistors in the audio loop is definitively a big NO-NO, just go ask any audiophile of Hi-Fists and he did not even need to be an extreme one to tell you this. So, I concentrated my efforts this way. First I produced this picture of what is short direct contact on my X-Fi Fatal1ty: http://i232.photobucket.com/albums/e...ps_outputs.jpg

And todays I go deeper. It is same for each output. After opamp, there is a 33ohm resistor to protect the opamp from shortcut on the end. It has minimal impact on the signal, so, keep it. Later there are two muting transistors, for the positive and negative flow:

And after them a two small caps to the ground to kill the possible high frequency interference. For L and R channels the card utilize 4 separate transistors. For the rest a dual transistor is used to save space - two (or coudl that be four?) ones in one.

Regardless, the removal is rather easy. First get rid of them:

Then solder a shorts there:

...and you are free to test them. As you probably noticed, I for the work desolder the C46 and C27. And also as you sure noticed, I replaced the LM4562 opamps with AD8599 ones.


The results.
After hearing the sound, I was like "Holly ****...!"
There is no words to describe how much better it sounds. The oversharped thick sound of the LM4562 is gone (LM4562 also like to pick a lot RFI) and the sound is rich and full - and yet more detailed - very likely thanks to these muting transistors removed!

Fantastic change, damn I'm glad I did it!

Side-effects.
As everything in life, there is a price for this. Not only this is NOT easy mod (do NOT try that, unless you are soldering MASTER, and I'm not kidding) but it also has consequences. Not only you want to delete all, even the 320kBi mp3 files now, but upon the driver loading in windows boot, there is notable click in the speakers. Same when changing audio mode. Not louder that the amp is set for, so a minor price for such wonderfull, rich sound.
There is a bigger price and I was quick to discover it.
I remember it well from measuring the voltages on the caps on X-Fi. When I touch the opamps, well, then the X-Fi started to oscilate like MAD and the resulting sound noise, even on small testing speakers, are unbearable.
So, to get to it - I plug my rear speakers into the SUB/CENTER jack, so upon discovering that, I was like fixing this. So I unplug the jack... and the moment it started. The X-Fi, no longer protected with these muting transistors, start oscilating like mad. From all 6 speakers it output SO horrible noise and SO strong, that it was like when F18 is about to land on your head.
I can't remember anything comparable in my life.
My stepbro run to my room asking What... so you get the picture.
The oscilating noise, when you change your speakers, does not stop till reboot.

For me it is fair price to pay. I just can't now hotplug the speakers of fiddle with them "on the fly", like I used to. This is kinda sad and limiting, but what one can do. I'm ceratainly not going to put these cursed transistors back, no way. I love the sound now way too much.

 

[kaducii]

Hi, my friend recently modded my SB0460 (XtremeMusic) X-fi card with the 2200uF capacitor mod and the opamp mod (all 4 op amps). Now when I plug the sound card into the computer I get sound but it is mapped weirdly. (I did not change any wires of the actual speakers or anything and they are wired to the correct jacks.) I'm using a 5.1 sound system.

Here is how the sound maps now
Default Channel Which speaker sound is actually produced
Front Left Front Left
Front Right Rear Right
Rear Right Rear Left
Rear Left None
Center Front Right
Sub Center

Obviously something got screwed up on the card. My question is, would something like this be caused by the Opamp not being installed correctly or from another part of the card that may have been damaged during the solder process?

Thanks for any help.

 

[Random Murderer]

Quote:

Originally Posted by kaducii /img/forum/go_quote.gif Hi, my friend recently modded my SB0460 (XtremeMusic) X-fi card with the 2200uF capacitor mod and the opamp mod (all 4 op amps). Now when I plug the sound card into the computer I get sound but it is mapped weirdly. (I did not change any wires of the actual speakers or anything and they are wired to the correct jacks.) I'm using a 5.1 sound system. Here is how the sound maps now Default Channel Which speaker sound is actually produced Front Left Front Left Front Right Rear Right Rear Right Rear Left Rear Left None Center Front Right Sub Center Obviously something got screwed up on the card. My question is, would something like this be caused by the Opamp not being installed correctly or from another part of the card that may have been damaged during the solder process? Thanks for any help.

it could be that some of the opamps were installed incorrectly, the wrong type of opamps were used, or something even more unlikely.

 

[Hayduke]

Quote:

Originally Posted by kaducii /img/forum/go_quote.gif Hi, my friend recently modded my SB0460 (XtremeMusic) X-fi card with the 2200uF capacitor mod and the opamp mod (all 4 op amps). Now when I plug the sound card into the computer I get sound but it is mapped weirdly. (I did not change any wires of the actual speakers or anything and they are wired to the correct jacks.) I'm using a 5.1 sound system. Here is how the sound maps now Default Channel Which speaker sound is actually produced Front Left Front Left Front Right Rear Right Rear Right Rear Left Rear Left None Center Front Right Sub Center Obviously something got screwed up on the card. My question is, would something like this be caused by the Opamp not being installed correctly or from another part of the card that may have been damaged during the solder process? Thanks for any help.

I'm trying to imagine anyway that this mod could have caused this. It is most likely related to the op amps. If you double check the polarity (if any) on your caps, that will rule out the possibility of the caps causing the problem. The next question would be which op amps did you use? Maybe you used a single instead of a dual or something? Did you double check the polarity on those too?

I'm sure someone smarter then me will be able to help you. Good luck

 

[NoKKiE]

Quote:

Originally Posted by Hayduke /img/forum/go_quote.gif I'm trying to imagine anyway that this mod could have caused this. It is most likely related to the op amps. If you double check the polarity (if any) on your caps, that will rule out the possibility of the caps causing the problem. The next question would be which op amps did you use? Maybe you used a single instead of a dual or something? Did you double check the polarity on those too? I'm sure someone smarter then me will be able to help you. Good luck

Hello, I am actually the one who installed the op amps. All the op amps were installed right and I checked it with all the connections with a multimeter. The op amps used were LME49720MA, although on the op amps themselves it only says L49720MA (not sure if that matters, doesn't ME only signify higher quality?). I'm dumbfounded by the problem myself, I thought all of the channels were controlled by separate op amps.

All the polarities seem right. Do all cards have the op amps point in the same direction?

 

[Apocalypsee]

Quote:

Originally Posted by NoKKiE /img/forum/go_quote.gif Hello, I am actually the one who installed the op amps. All the op amps were installed right and I checked it with all the connections with a multimeter. The op amps used were LME49720MA, although on the op amps themselves it only says L49720MA (not sure if that matters, doesn't ME only signify higher quality?). I'm dumbfounded by the problem myself, I thought all of the channels were controlled by separate op amps.

Mine wrote L49720 as well, and it plays nicely

Your problem is weird though, I have no idea what causes that. Good luck with that

EDIT: Here is the picture (taken from trodas), note that the holes on the opamp, that denotes pin 1. Make sure yours facing the same way