Finally received and tryed several opamps mentioned in the forum and ended up with LME49720 and LME49860 since i ordered one each instead of ordering a pair but thanks god it works excelent and realy gives more little details but i think they need few hours of burn-in to open up.

I've only ever heard burn-in with AD797.  It was rounded at first use, then after a few hours it attained the excellent balance that people post about.

But for me LME49720 and LME49860 initially didn't sound the way they sound now with such natural clear transparent details with any kind of music i throw in, much better than i had with Auzen X-Fi Prelude with stock opamp (tryed OPA627 and OPA637 on it but they just gave bass quantity that's it)

Hm, I'm curious about this OP amp thread. I have a Xonar DS and just opted to replace it with the Xonar Essence, delivery due in a few days. I rebuilt an older Adcom DAC about a year ago using a pair of OPA627AU with fine results... had tried 1 as a lark in the DS but without sheilding it picked up too much noise. Will try those first and probably try some of the other recommendations. For me this is a fairly serious effort as I've built a custom hardware optimized music server and the only alternative seemed to be buy an external USB reclocker and new DAC which would have cost significantly more.

Recieved the Essence STX PCI sound card the other day and spent a frustrating hour trying to get it installed where the the latest install software couldn't recognize the card. Problem promptly gone when I used the previous software installer version. In retrospect the issue was staring me in the face...Asus latest installer shows that its for PCI-E whereas the earlier (working) version showed it was for PCI. Boo to Asus for not differentiating the install packages on their web site.

Once up and running I played through a few favorites on my music server. Much better definition than the Asus DS, better base timber, solid chord color so that instruments had presence and life. However that annoying "tss" sibilance and irritating edginess effect was back which I spent the last 6 months rooting out of my system. So to work

1) hadn't bothered before but with a better sound card I decided it was worth swapping the stock PC power cable for a Pangea SE-14 A little smoother now and base impact improved but a ways to go.

2) swapped in the OPA627AU opamps, tangible relief as soon the music played.  Edge and sibilance gone,

So overall for first 24 hours pretty satisfying. Tonal colors and dynamics are besting my modded Oppo DV-970HD player. However in the area of fine details the Oppo playing CD seems clearer vs PC playback.( note all my CD rips are  uncompressed wav format using dbPoweramp to avoid decoding processing jitter. Playback using Foobar or JRiver Media player with kernel streaming or wasapi).

And the included opamps (2114D) should be swapped out ASAP for a better choice if you buy this.

In setting up the card I came across one construction detail that promises further hope. The card does not rely on PCI bus power for its analog, but has a connector for 4 pin power same as IDE drive.

Next steps:  the headphone amp section tryout and finding an independent power supply for the card

since this post and last I've  tried a few things. Never found an external power supply for the card, but did upgrade the PC chassis power supply from 400 watts to 650. I swapped the OP627AU op amps in, they sound sweeter but really don't click as a worthwhile change. The headphone section is nice, easy to listen to with the stock op amps...but (and here comes the big but)... about 10 days ago I purchased a Musical Fidelity Vlink Asynch to USB converter. This device out to my aged DAC is so much closer to real performance for transients, base and musical detail that I'll be retiring the Essence STX.

Too bad AD8066 OpAmp wont work in this baby =( I'm havin this baby too, just that I tried 2XOPA2227 + AD8066 setup and 3X AD8066, and it didn't work for me... T.T sad

Quote:

Originally Posted by davide256 

2) swapped in the OPA627AU opamps, tangible relief as soon the music played.  Edge and sibilance gone,

Hey David.  Did you use the OPA627s in the I/V section or the buffer section?

Bump! Was thinking of getting the LME49860NA and trying that out in my Asus Xonar STX. I'm new to this and don't fully understand why this particular piece is different and/or better and what role it serves, so information on that, and how to install would be appreciated. Or even pointing me towards info on how to do it, but I figured I'd start here since ya'll have done this very specific task before.  

Thanks!

edit: or maybe the opa627au is better? appreciate any guidance. 

 http://www.newark.com/texas-instruments/opa627au/ic-op-amp-16mhz-55v-%C2%B5s-soic-8/dp/30C4516?in_merch=Popular%20Products

Quote:

Originally Posted by Riggaberto 

 

Bump! Was thinking of getting the LME49860NA and trying that out in my Asus Xonar STX. I'm new to this and don't fully understand why this particular piece is different and/or better and what role it serves, so information on that, and how to install would be appreciated. Or even pointing me towards info on how to do it, but I figured I'd start here since ya'll have done this very specific task before.  

 

Thanks!

 

edit: or maybe the opa627au is better? appreciate any guidance. 

 http://www.newark.com/texas-instruments/opa627au/ic-op-amp-16mhz-55v-%C2%B5s-soic-8/dp/30C4516?in_merch=Popular%20Products

The stock op-amps on the STX are fairly neutral, changing op-amps is better answered on the thread listed below.

You can get 3 LME49860NAs on eBay for $15, it's a low cost way of getting in to op-amps (operational amplifiers).

Also on eBay someone has the LME49990NAs for $18.50, pre-mounted ready to install.

(The LME49990NAs have to be mounted in pairs to a SOIC to DIP-8 adapter).

Also the AD797 are well liked, they as have to be mounted in pairs (two per adapter), you can get them off ebay (pre-mounted)

But they ship from China, land of the fake, relabeled stuff, but the prices are good.

Anyway, basicly, you need to remove 4 small philipshead screwes on the Essence STX to take off the shield, then pop out the op-amps and put in the new ones.

Check out the "Essence STX Q/A Tweeking Impression Thread" on Head-Fi.

Thanks for the reply! Just for clarification, what is the "pre-mounted" aspect of things you mentioned with the ebay listing, versus also saying all you need to do is unscrew the shield, and pop the amps in and out?  

Appreciate the advice.
 

Quote:

Originally Posted by PurpleAngel 

The stock op-amps on the STX are fairly neutral, changing op-amps is better answered on the thread listed below.

 

You can get 3 LME49860NAs on eBay for $15, it's a low cost way of getting in to op-amps (operational amplifiers).

 

Also on eBay someone has the LME49990NAs for $18.50, pre-mounted ready to install.

(The LME49990NAs have to be mounted in pairs to a SOIC to DIP-8 adapter).

 

Also the AD797 are well liked, they as have to be mounted in pairs (two per adapter), you can get them off ebay (pre-mounted)

But they ship from China, land of the fake, relabeled stuff, but the prices are good.

 

Anyway, basicly, you need to remove 4 small philipshead screwes on the Essence STX to take off the shield, then pop out the op-amps and put in the new ones.

Check out the "Essence STX Q/A Tweeking Impression Thread" on Head-Fi.