[rjm003]

@Burson Audio
With input offset bias currents for the SS V5 module in the hundreds of microamps (compared to nanopamps for the NE5532) I'm a little concerned about the output offset voltages. From your published datasheet and the PCM1792A example circuit I estimate the offset might reach as high as 100-200 mV. Can you confirm the offsets at both the output of the IV and LP stages for us please?

 

[Burson Audio]

Are you looking at the new V5 data sheet? It only require 7ma not hundreds It is very well suited for PC sound card project. 

 

[Burson Audio]

  @Burson Audio
With input offset bias currents for the SS V5 module in the hundreds of microamps (compared to nanopamps for the NE5532) I'm a little concerned about the output offset voltages. From your published datasheet and the PCM1792A example circuit I estimate the offset might reach as high as 100-200 mV. Can you confirm the offsets at both the output of the IV and LP stages for us please?

 
You maybe thinking about the V4 opamp. The V5 has been redesigned for lower voltage and less current drawn. Only require 7ma so it is very well suited for PC sound card mod. Not to mentioned the much smaller profile.

 

[MrHeadphone]

Hey guys, quick question about the Xonar STX Soundcard. Im using the RCA Outputs into a 2.1 Soundsystem with an integrated amp .
 
When I set the Volume to 80-100% in the Asus driver on Windows, the Sound gets very distorted, so I have to keep it at about 50-60% for "clean" audio. Is my card broken or is it normal, that the audio gets "scratchy" on higher volume level?
 
The Headphone output on the other hand sounds very clean, even on 100% volume. So Im concerned about the RCA Volume issue.
 
Please let me know what you think.

 

[lucianpescaru]

Plug your headphones or another amplifier to the RCA outs.

 

[PurpleAngel]

  Hey guys, quick question about the Xonar STX Sound card. I'm using the RCA Outputs into a 2.1 Sound system with an integrated amp .
When I set the Volume to 80-100% in the Asus driver on Windows, the Sound gets very distorted, so I have to keep it at about 50-60% for "clean" audio. Is my card broken or is it normal, that the audio gets "scratchy" on higher volume level?
The Headphone output on the other hand sounds very clean, even on 100% volume. So I'm concerned about the RCA Volume issue.
Please let me know what you think.

 
Did you disable the motherboard's on-board audio, in the BIOS, when you installed the Essence STX?
 
Might also try replacing the Asus drivers with the Unified Xonar Drivers.
http://maxedtech.com/asus-xonar-unified-drivers/

 

[MrHeadphone]

  Plug your headphones or another amplifier to the RCA outs.

Turned out that plugging my headphones directly into the RCA Outs, even on 100% volume there is no distortion or scratchy noise. Does that mean the distoriton is due to my 2.1System?
 
My Setup:
Xonar STX -> RCA LR OUT -> Teufel 2.1 Concept C200 BE
 
The 2.1 System has an integrated amp and I asume that the amp is somehow causing the distortion, but only when windows volume is set higher then 70%.
 
Example Szenario: 1) Windows sound is set to 100% and the 2.1System Volume is set to minimum=Distortion
                            2) Windows sound is set to 50%, 2.1 System volume set to maximum = No distortion
 
What could be the reason for this?

 

[rjm003]

   
You maybe thinking about the V4 opamp. The V5 has been redesigned for lower voltage and less current drawn. Only require 7ma so it is very well suited for PC sound card mod. Not to mentioned the much smaller profile.

 
@Burson Audio
 
I was referring to the input bias currents and the resulting, possibly high, output voltage offset. This has nothing to do with the power consumption or the current draw of the package.
 
Please measure the output offset voltages of the op amps when used in the STX. They might be dangerously high.
 
No offence but are you an intern or something? It's rather worrisome that someone working at Burson wouldn't know to check this when testing a module in any new circuit environment.

 

[Burson Audio]

   
@Burson Audio
 
I was referring to the input bias currents and the resulting, possibly high, output voltage offset. This has nothing to do with the power consumption or the current draw of the package.
 
Please measure the output offset voltages of the op amps when used in the STX. They might be dangerously high.
 
No offence but are you an intern or something? It's rather worrisome that someone working at Burson wouldn't know to check this when testing a module in any new circuit environment.

The new V5 has a very low DC offset measurement of 5mv due to its new design.  

 

[rjm003]

The output DC offset voltage is application dependent. It depends on the gain, the input offset voltage, input offset current, input bias current, and the impedances seen by the IN+ and IN- inputs.
 
 
(And shouldn't you be the one telling me this, and not the other way around? This whole conversation is surreal...)
 

 
Those are the datasheet values for the SS V5. For low gain, high impedance application with unbalanced input loading the key number is the maximum input bias current of 0.27 mA. The maximum output offset voltage expected under this approximation is (Zin- - Zin+) * 0.00027 A * GAIN. Far from 5 mV, the output offset voltage in any real circuit could easily be 1 V or more.
 
If you consider the following example,
 

 
The output offset with the SS V5 could be as high as (10k-909 ohms) * 0.00027 * 11 = 27 volts. (The comparable figure for the NE5534, max bias current 0.000002 A, is 200 mV) For the STX it shouldn't be anywhere like as bad, but given your module has input bias currents and input offset currents 100 and 1000 times higher, respectively, than the ICs they are designed to replace don't you think it would be prudent to actually go and measure it with DVM and get back to us with this information?

 

[MrHeadphone]

  Turned out that plugging my headphones directly into the RCA Outs, even on 100% volume there is no distortion or scratchy noise. Does that mean the distoriton is due to my 2.1System?
 
My Setup:
Xonar STX -> RCA LR OUT -> Teufel 2.1 Concept C200 BE
 
The 2.1 System has an integrated amp and I asume that the amp is somehow causing the distortion, but only when windows volume is set higher then 70%.
 
Example Szenario: 1) Windows sound is set to 100% and the 2.1System Volume is set to minimum=Distortion
                            2) Windows sound is set to 50%, 2.1 System volume set to maximum = No distortion
 
What could be the reason for this?

 
EDID: It gets weird.

Asuming my 2.1 System was causing the distortion, for testing purposes I pluged my Iphone, Notebook and OnboardSoundcard of my PC to my 2.1System with 100% Windows Volume and there was no distortion whatsoever.

Afterwards I hooked up the STX Soundcard to my old Denon Amp, 100% windows volume and....no distortion.
Somehow the STX Soundcard and my 2.1 System wont get along with each other, at least when windows volume is set higher then 70%. But why? Im guessing it has something to do with impedance, but it would be very great to get some input from you guys here.

Please let me know what you think.

 

[rvcjew]

EDID: It gets weird.


Asuming my 2.1 System was causing the distortion, for testing purposes I pluged my Iphone, Notebook and OnboardSoundcard of my PC to my 2.1System with 100% Windows Volume and there was no distortion whatsoever.


Afterwards I hooked up the STX Soundcard to my old Denon Amp, 100% windows volume and....no distortion.
Somehow the STX Soundcard and my 2.1 System wont get along with each other, at least when windows volume is set higher then 70%. But why? Im guessing it has something to do with impedance, but it would be very great to get some input from you guys here.


Please let me know what you think.

Perhaps the 2.1 with stx is causing a ground loop, and you need a ground loop isolator in between. Is the distortion with a hum included?

 

[MrHeadphone]

Perhaps the 2.1 with stx is causing a ground loop, and you need a ground loop isolator in between. Is the distortion with a hum included?

There is no hum or static noise. Its a typical distortion sound (boosted, uneven and "scratchy / crackly"). Could it be that the STX needs a higher quailty amp like my Denon, because as mentioned, with the Denon Amp there is no problem in soundquiality. 
 
Connecting the 2.1 System to my notebook or iphone did not repreduce the distortion. So the 2.1 System is working. Maybe the STX RCA Output has a too high preamplification for the 2.1System?? I really want to solve this here... but Im out of Ideas.

 

[rvcjew]

  There is no hum or static noise. Its a typical distortion sound (boosted, uneven and "scratchy / crackly"). Could it be that the STX needs a higher quailty amp like my Denon, because as mentioned, with the Denon Amp there is no problem in soundquiality. 
 
Connecting the 2.1 System to my notebook or iphone did not repreduce the distortion. So the 2.1 System is working. Maybe the STX RCA Output has a too high preamplification for the 2.1System?? I really want to solve this here... but Im out of Ideas.

Does the denon have like a zone 2 preamp out of its own that you could hook to the 2.1 system after hooking the stx to the denon normally, that would boost the signal to the 2.1 system. Perhaps the 2.1 is not getting enough of a signal from the stx. Your other sources: laptop and iphone, would already be amped to some degree. Is it distorted at any volume? EDIT: just noticed that your 2.1 has a headphone out on the volume console, if you plug in your headphones to that area is the signal still distorted?

 

[MrHeadphone]

  Does the denon have like a zone 2 preamp out of its own that you could hook to the 2.1 system after hooking the stx to the denon normally, that would boost the signal to the 2.1 system. Perhaps the 2.1 is not getting enough of a signal from the stx. Your other sources: laptop and iphone, would already be amped to some degree. Is it distorted at any volume? EDIT: just noticed that your 2.1 has a headphone out on the volume console, if you plug in your headphones to that area is the signal still distorted?

First of all thanks a bunch for your effort. As you suggested, I pluged my headphones into the headpohone out on the volume console of the 2.1System and yes, distortion is there as well.
I tried the RCA Pre-Out on the Denon Amp, but I wasnt able to get Sound.
 
To sum up: Setting is always 100% Windows Volume.
1) XonarSTX ->RCA Out -> 2.1System = Distoriton
    XonarSTX ->RCA Out -> 2.1System > Headphones on Headphone Out = Distoriton
    Xonar STX->RCA Out -> Headphones = No distortion
 
    Xonar STX-> Denon Amp= No distortion
    Xonar STX-> DVD Player RCA input = No distortion
 
2) 2.1System. -> Notebook = No distortion
    2.1System -> Iphone full Volume = No distortion
    2.1System -> SamePc with OnBoard Soundcard = No distortion
One note: Since the Notebook, Iphone and Onboard have 3,5mm out, im using a 3,5mm to RCA LR adapter into the 2.1System.
 
Finally I just want to remember that setting Windows Volume to around 60% and lower, solves the distortion problem with the STX-2.1 Setup.
 
^^Any Ideas?