Asus Xonar Essence STX Audio Sound Card

Here's a spek readout of the Xonar ST capturing silence at -86.0dB, amplified to an audible level. On playback, it sounds like nothing but pure white noise - no audible harmonic or transient response. In spek the frequencies look very pure, almost like grains of sand. I can't wait to needledrop with this card!

 

I purchased the STX model and installed... had a great deal of trouble getting the software to install properly on my WIN 7/64 PC but finally did. Two questions...

1) I thought I read somewhere that the headphone jack (with jack inserted) nullified the RCA speaker outs. But I can only switch between headphone out and speaker out via the Xonar Audio Center panel. Is that correct?

2) There is a pin connector on the top of the card for connection to a front PC panel. I would like to be able to use a front panel for the headphones and perhaps the "line in" port. I'm assuming that the headphone output from the front panel would be the same sound quality as that on the rear. (using the built in headphone amp) Can someone recommend a good PC "front panel" for connection to the Essence STX in my PC.

Thanks....

 

I have the Nexus Psile silent PC case but I have been having trouble settling on an ITX motherboard that would suit my purposes. The Asus Atom motherboard I was looking at was discontinued, perhaps due to RAM sensitivity issues that people were reporting (the board seemed to be compatible with only a slim selection of RAM from a few manufacturers). I had spec'd out a quiet PC based on a Core2 mobo, but the Core2 is now outdated and also requires a processor fan. The hunt continues!

 

Sure thing! I PM'ed keoki82 the specs of the system I had originally assembled. I spec'd it with an eye toward vibration control, silent operation, and heat dissipation. Here are the specs below:

Intel Core 2 Duo E8400 3.0GHz 6MB L2 Cache LGA 775 65W Dual-Core Processor
Asus P5Q-EM Intel G45 Express Motherboard
Asus Xonar Essence ST or Asus Xonar HDAV1.3
Asus BC-06B1ST Blu-ray drive
Corsair TWIN2X4096-6400C5 G 4GB DDR2
Western Digital Caviar® GP SATA 1 Terabyte Hard Drive

Nexus DampTek Noise Absorption Material
Asus Triton 85 CPU cooler
Nexus 120mm Real Silent Computer Fan - Black & White with Fan Mounts
Fansis 120mm Anti Vibration Fan Gasket Clear FS-120
Fansis Anti Vibration Soft Silicone Power Supply Gasket (also includes 8 bushings to use on hard drive and Blu-ray drive)
Nexus 430w Compact ATX Quiet Power Supply
Nexus PHT-7750 Copper Socket 775 Quiet CPU Fan
Nexus Copper Northbridge Cooler
Grow Up Japan Smart Drive 2002 Copper Hard Drive Enclosure

 

Hey Eric,
Where'd you purchase the Nexus Psile case? I'm having a difficult time finding a retailer. It's unlikely it would be discontinued as there's not much like it available.

 

The solidity, texture and sensitivity to dynamics is exactly what I heard out of the box as well. The onboard sound on my motherboard is the best I've ever heard, although it still has nothing on the Xonar ST. I'm running my Sennheiser HD 580's at the 300-600 ohm level, and it's breathtaking.

I take it the hardware clicks during startup and line/source switching is normal? The card behaves like a control amplifier in this regard. Very intriguing.

 

Glad you're enjoying the higher quality sound.

Yes it is normal.

Correct (in Windows(tm), in Linux with ALSAMixer). One or the other is active, switched by the driver. Plugging in the headphones does not nullify the RCA outputs. Switching the driver to headphone output does.

No, you would be introducing the cheap-o connections, wire and plug of a front panel between the analog output and the headphones. Similarly with the "line in." For best quality, it would be best to use the connections built onto the card for either purpose. There is also the potential practical consideration that the card has 1/4" plugs and a front panel type plug will typically be 1/8" mini-jack.

 

Chris... Thanks for the answers... I'll just purchase a good quality headphone extension cord.

 

I purchased directly from Nexus. They have a Psile website. I think that cooltechpc.com is the US distributor for the Psile case, but they only sell full systems.

http://www.psile.com/index.php?page=wheretobuy

There was a Psileshop.com website that Nexus operated where you could purchase the case only--that's what I did. Not sure if it still exists.

You may be able to purchase from the UK at mini-itx.com.

 

Here is the link to buy from Nexus:

www.psile.com/index.php?ID=6

 

I am now seriously thinking about this mobo:

http://www.asus.com/Motherboards/AMD_CPU_on_Board/E35M1I_DELUXE/

 

FYI--new thread you guys might be interested in:

http://www.stevehoffman.tv/forums/showthread.php?t=278770

 

You'd have to go with the STX.

 

Yeah, I know.

 

Help! How do Xonar owners do their needledrops!

Tonight I tried making drops for the first time since I bought the Xonar ST. I ran an RCA-to-miniplug cable from the ouput on my control amplifier and plugged it into the Line In on the Xonar panel using the supplied quarter-inch adapter.

I was careful to uncheck Front Panel Microphone and Microphone Boost settings in the Windows Recording Devices. The first thing I noticed is that the mic volume is set to 100 in Xonar Audio Center and yet the input is very low compared to when I use my 24/48 USB device for drops.

I like to center my recordings. Even though I capture to 24-bit, I like to bring the level as near to 0dB as possible without clipping (usually about -1dB from peak), so that less processing is required later, and so less hiss is picked up from the PC and the control amplifier.

Unfortunately, when I turned the volume knob on my control amplifier to a level that brought the signal to near -1db, the input started to distort badly. My control amp is fairly aggressive, and using efficient loudspeakers, I rarely have to turn the volume knob past 9 oclock. I had to turn it to 12 oclock to bring the signal as near 0dB as possible, but it sounded terrible. I tried playing around by turning down the mixer volume instead, but no matter what I do, the Rotel output seems to overload the ADC on the Xonar past the 9 oclock position on my volume knob.

As a result, I left the volume on my control amp at 9 oclock and the mixer volume in Xonar Audio Center at 100, since this volume is not causing distortion or clipping. I decided to capture at 32-bit float, but even still I am concerned about amplifying excess noise, as the peaks of the signal are only reaching about -15dB during capture.

Help!

 

FYI, for those that are interested, the Nexus Psile case has been EOL'ed. My company is in discussions with Nexus to buy the remaining stock and ship it over from The Netherlands. Not sure how many units exist.

 

Do not try to do this. Limit your recording levels to a maximum of -6dbFS and you will achieve better sound. Barry Diament has commented on this numerous times in the past. It is due to the distortion characteristics of ADC chips.

What software are you using to record with and what API? If you are using Windows 7 you should be using software that supports either ASIO or WASAPI. In either case, you should always set your recording volume control in the Xonar control panel to 100. To do otherwise will reduce the available resolution, as the recording mixer controls for the Xonar are purely digital - they do not control the input level to the ADC chip.

And refering to my previous response above, with your mixer volume to 100, aim for your recorded peaks to not exceed -6dBFS.

If you are getting distortion at these lower recording levels when using ASIO / WASAPI based recording software with mixer at 100, then I would be looking at something being wrong with your input source, not the Xonar card or anything at the recording end.

32 bit won't make any difference to your S/N ratio - the 32 bits simply allows for processing headroom (for example, if you were to apply some sort of DSP during processing that caused the levels to fall outside a 24 bit envelope, the levels would not be forever lost during a subsequent normalisation). What is much more important is the internal precision of your recording / editing software. If it has 64 bits or better internal precision then there is no advantage of recording at 32 bit floating. Given you should be keeping the peaks well below 0dBFS to begin with, just record in 24 bits.

Finally, I would only be concerned about the S/N ratio of your recording if the S/N ratio of your input source is worse with the volume control at lower positions versus higher positions. Since i don't know enough about your source I can't answer that one. Were this the case though, the solution would normally be analogue attenuation of the source outputs leading to the Xonar line input jack.

But since you are distorting at the source end seemingly well within the input headroom capabilities of the Xonar, it would seem something is amiss with the source.

In my own case, my analogue input to my Xonar is capable of producing peaks sufficently high that the Xonar will soft clip them (so the distortion is only audible in the same sense that a limiter is audible). I resolve this by using 12dB attenuators on the line input to the Xonar. My recording levels tend to be around -12dBFS on average (sometimes as low as -20dBFS) and the resulting sound is still excellent with no audible noise added that was not audible on the original source.

For my final listening, because the DAC in my listening room is 16 bits, I will normalise my output to -0.2 dFBS peak and then dither it using MBIT+. This preserves as much S/N ratio as possible in the final conversion to 16 bits.

 

Jon, thanks so much for your input. I really appreciate it. I'm using version 7 of Sony Sound Forge because I enjoy the interface and can't afford to buy version 10. There's nothing wrong with my source; I guess I was just concerned that a capture with peaks only reaching as high as -15dB would introduce more noise, since a 500% volume increase is required to bring the peaks to -0.2dB in post processing. I figured that 32-bit was a waste of time and will use 24 bit for future captures. My concern was that when tryng to increase the volume of the output signal on the control amp, the input grows increasingly distorted. I keep the mixer level on the Xonar card at 100 to avoid any digital processing that will affect resolution.

 

This question was never answered. It is pretty important I'd think. I haven't found any details on the net. I looked at the manual and it does state to set at the maximum setting of music you will play.. but it doesn't state whether or not it is upsampling the lower rate files.

I have mine set at 24bit 192 because I have some hdtracks.. but since I'm using the RCA outputs I have no way to see what is happening when I play most of my FLAC at 16/44.1. And no... I can't "hear" a difference.

 

By the way, this deal never happened. I assume the Psile cases are still sitting in a warehouse in The Netherlands.

 

Anyone have any insight to my question?

 

So hooking this up using the front panel connectors will degrade the sound? Seems silly to have to run an extension from the back panel to plug headphones in.