[Apocalypsee]

Quote:

Very interesting hack. I've taken apart mine and tried to find things to mod, but I'm not very good at tracing these things. Could you post more pics of the mod if you have time? Also, do the 'D' caps affect the headphone out or the RCA outs? Or both?

It affect both, its a DC blocking caps


 
Quote:

What mod could I do to use this same card with AKG K601 headphones? In another thread about modding  PCI x-fi cards the OP recommended LM4562 opamp. Can I use this one with the x-fi surround USB too?. Also is it feasible to unsolder the DAC and changing it by another better one one? It seems difficult as the DAC has quite more pins that the opamps.

No you cant change DAC as it pinout are different even though the number of pins are the same. I have modded mine and one caution, don't use LM4562. LT1364 is a better opamp
 

 

[mikeaj]

I have one of these and am wondering about it as well.  Although I have not tested this myself, I am pretty sure that op amp suggestions for the PCI/PCI-E X-Fi cards are not appropriate here because the USB X-Fi Surround 5.1 is powered by USB.  USB supplies only ground and +5 V, though the actual +5 V in practice may be a little lower.  PCI-E is +12 V and ground I think.  The 5 V difference is at the minimum end of the specified operating range for power supply rails for the LM4562 and similar op amps.  An op amp designed for low single-sided supply voltage should do much better.
 
The line out I think is a true line out, or else these RMAA results would not be at this level: http://ixbtlabs.com/articles3/multimedia/creative-xfi-surround-51-p2.html.  Consider the price of the device and how the amplifier section is the weak link.
 
Any thoughts?  Instead of modding it, I'm considering just using the RCA line out to feed a cheap amp.

 

[Apocalypsee]

I tested the RCA out and the headphone out, honestly I can't tell the difference.
 
I done my own mod to this. CS4361 datasheet suggest that there is no need for any opamp on output stage because of two reason, one is its voltage out DAC and the 2nd one is its not fully differential output (means it single ended). I managed to bypass the opamp by removing C30 and C20 capacitor (big yellow ones labelled B on the first page) and direct couple it to RCA out by making my own circuit by following the datasheet suggested analog out. Also, remove the C37 and C33 caps near the RCA out or the output signal is too low or you could use that too, but you need to do some calculation on the final caps, depending on the load impedance
 
But one thing I not so sure is is there any other caps or resistor before the C20 and C30 coupling caps (DC decoupling caps). It do sounds wonderful, much better than with opamp because no matter what opamp you put there it will be inadequate because of low supply voltage
 

 

[McFrede]

Could you write the exact values of the components you changed?

 

[Apocalypsee]

Quote:

Could you write the exact values of the components you changed?

I'll post it this weekend with some pics to show what I did. Too much things to do on weekdays

 

[Apocalypsee]

Finally have some time to post it. Here is the pic of my mod:
 

 
I bypass the opamp entirely and remove it along with SMD that relates to it. Mind you that the headphone out is totally unusable
 
The new circuit is based on modification from the CS4361 analog out recommendation, what I did is remove the 470 ohm resistor because this reduces the volume way too much if I driving through headphones, and also using 10uF instead of 3.3uF to boost the bass as after removing the 470 ohm resistor, the bass reduces at the same time. The decoupling capacitor near the output is just a random value I used.
 
I have contacted one of my friends who expert in electronics to help me with this and hopefully it'll improve further
 
CS4361 datasheet: http://www.cirrus.com/en/pubs/proDatasheet/CS4361_F1.pdf

 

[Galuwen]

Hi man !!
 
This modd is soooo cooool. THX for the GREAT INFO.
 
I am also uusing this module (card?) and I am happy with it.
 
QUESTION: What drivers do you use to get ASIO compatibility?
 
I use ASIO4all, NOT the BEST solution but it's doing the trick.
 
THX again.
 
Alexander

 

[Gele]

ThanX.
I`d be glad if someone could post here how to open the device without breaking it.
Mine has a more important than the signal quality issue - it sends a spike to the power amplifier (very annoying). It happens everytime when the USB bus is reset - when I power on the PC or when i do a software usb reset (under Linux).
I plan to fix it by slapping a really large capacitor somewhere (paralel to an output of a LDO regulator) to dampen the fronts of the impulse (if it`s caused by power on/off).
If the cause is RESET signal on a digital input pin, I`ll need a more sophisticated solution...
 
Regarding the quality of the DAC conversion - for me it`s important to check if the volume control is implemented by slicing bits from the samples (mul/div by 2/4/8/16/32/etc) or there is analog hardware potentiometers with digital control. Cheap usb devices do not have analog potentiometers. Software volume control reduces the samples resolution especially in 16-bit mode. If we want to prevent it, we need to set the volume to 100% on the software PCM and master controls and mount potentiometers in our homebrew amplifiers. Since the analog potentiometers are noisy things and for 5.1 one would need a lot (6) of them, a digitally controlled analog solution is needed. Something like MCP41010. But note - the digital potentiometers add harmonic distortions (~0.05%) and have capacitance.

 

[NeX01]

sorry to bump this but i am really interested in modding my USB sound card to have a line level output. Apocalypsee do you have any more pics or info on your mod? where are the points on the board where the audio comes in from the cirrus chip? and whats the state of the output to the surround sockets? are they line level only?
 
thanks guys

 

[NeX01]

don't make me bump this every day of the week

 

[NeX01]

bump

 

[Apocalypsee]

Quote:

sorry to bump this but i am really interested in modding my USB sound card to have a line level output. Apocalypsee do you have any more pics or info on your mod? where are the points on the board where the audio comes in from the cirrus chip? and whats the state of the output to the surround sockets? are they line level only?
 
thanks guys

Sorry that I haven't replied for long time. Ever since the forum changes to new layout its been bugging me to no end. I have no more interest in audio, not that I'm quit but I get much more things in life than just listen to music.
 
Back to your question, that is all the pics there is, the point where the lineout is C20 and C30 respectively. Remove the yellow caps and tap it to get lineout
 
Its the same story on surround channel, the opamp acts as preamp before ending it out to rear jack, to get line out simply remove the opamp and retrace the opamp pinout to find the line out. But you need to build a new circuit following the datasheet or the line out have very low sound even when amplified
 
 

 

[NeX01]

hey there,
 
that is great! thank you so much that is exactly what i wanted to know! i am going to have a go and see if i can build a circuit in the same way the datasheet says (i was thinking 10nf cap for the unlabled cap)
 
thanks again

 

[Sergedc]

Hi Guys,
 
All these mods seems very interting. 
First a quick word about my setup : Tube amp (Yaquin MC10L - a wonder) - X-Fi USB used as a DAC and Flac music on the laptop. 
I also have a X-fi  USB. I regretted buying it only after a few days when I realised that the optical out could only output 48khz and 96khz but NOT 44.1khz. Hence I can't get a bit perfect tranfer out of it.
 
1. Would any of you know why this is? And is so, would there be any mod that could cancel the upsampling of my 44.1khz music to 48khz?
 
2. I am considering to buy another divice. Ideally I would which to have USB 24/96 input (TE7022L seems great), an ok dac, RCA out and Optical out. I am donsidering the XiangSheng DA-04 (only on sales in China on Taobao). It has an external power but a small one (I guess this is a plus versus the X-FI). Also the DA-04 uses the TE7022L as USB chip and the  [size=100%][size=100%]WM8761[/size][/size] as the dac (which I understand is better than the one of the X-FI). Also it has a line out (RCA out).
Do you think that this device is a definite upgrade versus the X-FI?
 
http://item.taobao.com/item.htm?id=9172681059
 
Also, could you explain how the RCA output of the X-FI is not a line out? Is it because the sound goes trough a preamp in the X-FI? That is what I hate about this X-Fi, it is such a black box.
 
Thanks a lot,
Serge
 

 

[NeX01]

 
Quote:

Hi Guys,
 
All these mods seems very interting. 
First a quick word about my setup : Tube amp (Yaquin MC10L - a wonder) - X-Fi USB used as a DAC and Flac music on the laptop. 
I also have a X-fi  USB. I regretted buying it only after a few days when I realised that the optical out could only output 48khz and 96khz but NOT 44.1khz. Hence I can't get a bit perfect tranfer out of it.
 
1. Would any of you know why this is? And is so, would there be any mod that could cancel the upsampling of my 44.1khz music to 48khz?
 
2. I am considering to buy another divice. Ideally I would which to have USB 24/96 input (TE7022L seems great), an ok dac, RCA out and Optical out. I am donsidering the XiangSheng DA-04 (only on sales in China on Taobao). It has an external power but a small one (I guess this is a plus versus the X-FI). Also the DA-04 uses the TE7022L as USB chip and the  [size=100%][size=100%]WM8761[/size][/size] as the dac (which I understand is better than the one of the X-FI). Also it has a line out (RCA out).
Do you think that this device is a definite upgrade versus the X-FI?
 
http://item.taobao.com/item.htm?id=9172681059
 
Also, could you explain how the RCA output of the X-FI is not a line out? Is it because the sound goes trough a preamp in the X-FI? That is what I hate about this X-Fi, it is such a black box.
 
Thanks a lot,
Serge
 

i cant help you with your first problem but as for the RCAs not being line level, yea it goes through an internal pre amp, so it is amplified from line level. the point of line level is that the sound is as pure as it can be and then you pass it through a decent amplifier without adding any distortion. the preamp is the bottle neck for sound quality on this board