[Nosce Te Ipsum]

  Just installed the LME49990MA's ( LM6172 in buffer ) now and am listening to my reference track , from Al di Meola's " Cielo e Terra " - " Traces of a Tear " . Wow ! SQ is amazing , stage is wide , high and deep and extremely well-defined . Noisefloor is non-existant , by my perception anyway . This track has many quiet nuances , which all appear to be crystal-clear , timing is spot-on . Beautiful .
 
Hmm ... what to try for something with a bit of bass .... OK - Robert Rich's " Seven Veils " , 1st track " Coils " . Again , lots of fine detail , between the relentless onslaught of the very deep drums . It's very fast , LM6172 has slewrate that few can keep up with , so no bottlenecking . Definitely worth a try !

 
 

  Now for some visceral psychedelic bad craziness . Track no.2 from White Zombie's " Supersexy Swingin' Sounds " - " More Human than Human " . The STX doesn't get befuddled here either , everything stops and start exactly on time , juxtaposition of jagged noise and barely instantaneous silence . Gotta hear it to believe it . Ok , I think I'm freaking my neighbours out now . 

 
 
Remember , the buffer shouldn't affect headphones , only RCA outs , thus me using amp and speakers to listen .
 
Between LME49990MA and OPA1612 it's pretty close , but I'd still say that LME49990MA wins the day - damn they sound good .

Thanks for your listening impressions. Yes, you're right, the buffer only affects RCAs. Headphone out instead uses both the I/Vs and buffer if I remember correctly. Would you consider the LME49990MAs among the best of all those you tried? I just looked at the datasheet of both 4562/6172 and looks like the 4562 is more suited for a sound card etc. than the 6172... or maybe it's just my impression, don't know much about all that technical stuff. The "suspect" came from reading the data under the "Application" tabs.
 
Here are the links: http://www.ti.com/lit/ds/symlink/lm4562.pdf | http://www.ti.com/lit/ds/symlink/lm6172.pdf
 
Anyway, could you try the default 4562 (buffer) with 49990s (I/V) combination if you're not too lazy like me? Maybe you could find out that the 4562 is better than the 6172...

 

[Freshage]

Question for those using this form gaming as well.
 
The 'Game' mode sounds incredibly horrible. Truly. Is the 8 channels really essential when in hifi for gaming? 

 

[Freshage]

   
The LM4562 op-amp used in the STX's buffer slot is a relabeled LME49720.
 
For a low cost option you could replace the two JRC2114 op-amps with two LME49720.
Or replace all three of the STX's op-amps with LME49860
(the LME49860 is a cherry picked LME49720).
 
My final choice with my STX was three AD797BR (about $50-$60 for the three)

 
I can't for the life of me find these in the UK (or at least anywhere to buy from), any suggestions? I'm on about the AD797BR.

 

[fredeb]

   
I can't for the life of me find these in the UK (or at least anywhere to buy from), any suggestions? I'm on about the AD797BR.

 
http://www.mouser.co.uk/ProductDetail/Analog-Devices/AD797BRZ/?qs=sGAEpiMZZMv9yaQC4TiGCZp%252bzjCMT2SRpJ177c0LLRY%3d
 
You need 2 of these per Dual SOIC to DIP8 adapter , and you need the adapters . If I were you , I'd just order them made up from China on Ebay . I have done so with good results , if sellers on Ebay sell fake goods , they can get thrown off , and mostly it's worth their while staying on . Otherwise , why not try something that is available in DIP8 format , and be sure it's a dual-mono to dual opamp adapter as the AD797BR is a mono channel opamp and all the ones in the STX are dual opamps .

 

[fredeb]

@ Freshage
 
http://www.ebay.com/itm/mod-1x-AD797BR-Dual-to-Mono-Op-amp-module-ultralow-noise-replace-a-dual-op-/261266640288?hash=item3cd4b48da0:g:cbAAAOxyjxlTON9~
 
You have to see an AD797 above and below the DIP9 adapter board .
 
... and cheaper 
 
http://www.ebay.com/itm/1x-Dual-to-Mono-Op-amp-module-AD797BR-replace-OPA2604/262450099170?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%26asc%3D38530%26meid%3Df9a20163266a41ba83f374daa1e8d320%26pid%3D100005%26rk%3D4%26rkt%3D6%26sd%3D272462906198

 

[Freshage]

  @ Freshage
 
http://www.ebay.com/itm/mod-1x-AD797BR-Dual-to-Mono-Op-amp-module-ultralow-noise-replace-a-dual-op-/261266640288?hash=item3cd4b48da0:g:cbAAAOxyjxlTON9~
 
You have to see an AD797 above and below the DIP9 adapter board .
 
... and cheaper 
 
http://www.ebay.com/itm/1x-Dual-to-Mono-Op-amp-module-AD797BR-replace-OPA2604/262450099170?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%26asc%3D38530%26meid%3Df9a20163266a41ba83f374daa1e8d320%26pid%3D100005%26rk%3D4%26rkt%3D6%26sd%3D272462906198

 
Cool, think I'll order 3 of these: http://www.ebay.com/itm/mod-1x-AD797BR-Dual-to-Mono-Op-amp-module-ultralow-noise-replace-a-dual-op-/261266640288?hash=item3cd4b48da0:g:cbAAAOxyjxlTON9~&rmvSB=true
 
Hopefully I'll notice a difference Fairly new to all of this.

 

[fredeb]

   
Cool, think I'll order 3 of these: http://www.ebay.com/itm/mod-1x-AD797BR-Dual-to-Mono-Op-amp-module-ultralow-noise-replace-a-dual-op-/261266640288?hash=item3cd4b48da0:g:cbAAAOxyjxlTON9~&rmvSB=true
 
Hopefully I'll notice a difference Fairly new to all of this.

Hmmm .... I'm wondering if you shouldn't just order 2 pairs and then go for LM6172 in the buffer , or just stick with the LM4562 that should be there already .
 
.... and yes , the link you chose looks like the neater set . You should notice a huge difference from the stock JRC 2114D’s .
 
Also be sure to look at page 1 of this thread , as various peoples' opinions of trying different combinations are listed there .

 

[Freshage]

  Hmmm .... I'm wondering if you shouldn't just order 2 pairs and then go for LM6172 in the buffer , or just stick with the LM4562 that should be there already .
 
.... and yes , the link you chose looks like the neater set . You should notice a huge difference from the stock JRC 2114D’s .
 
Also be sure to look at page 1 of this thread , as various peoples' opinions of trying different combinations are listed there .

 
Cool, I'd like to upgrade the buffer as well to learn to see if I can notice a difference in them. Any helpful links for that one?
 
Thanks!

 

[fredeb]

   
Cool, I'd like to upgrade the buffer as well to learn to see if I can notice a difference in them. Any helpful links for that one?
 
Thanks!

http://www.mouser.co.uk/ProductDetail/Texas-Instruments/LM6172IN-NOPB/?qs=QbsRYf82W3HiTd0xlL7RxQ==

 

[Nosce Te Ipsum]

Looks like Texas Instruments removed anything about the LME49990MA ... all the others opamps are still there
 
http://www.ti.com/lsds/ti/amplifiers/op-amps/audio-op-amps-products.page#
 
In the Mouser page it is considered 'obsolete' .. no idea why.
 
http://www2.mouser.com/ProductDetail/Texas-Instruments/LME49990MA-NOPB/?qs=%2fha2pyFadugkO7ci4kEFwm%2fTOLuIktPP%252bvUpLGztZwELysmnINk%2fD7bXnuEi%2f42%252b

 

[bcschmerker4]

Speaking of Texas Instruments®, I read of other dual audio amplifiers that might be suitable for line-level buffer.  We know about the National Semiconductor® LM4562N, LME49720NA and LME49860NA.  But additionally, the Brown-Burr® OPA1642 has a mild 11 MHz gain-bandwidth product, 20 V/μS slew, and 5.1 nV/√Hz noise figure; the OPA1612, a 40 MHz gain bandwidth product, 27 V/μS slew, product and 1.1 nV/√Hz noise figure.  Both OPA's can go rail to rail at the output and are safe to 36 VDC supply.

 

[jimwallen]

My opinion and experience go hands down to the Burson Supreme Op Amp V5. It's a huge leap in sound quality-pick an adjective-than any of the ic chips mentioned. I tried them all, obsessive tweaker that I can be! I don't have a horse in this rate, I just want to share my experience with you.

 

[fredeb]

  My opinion and experience go hands down to the Burson Supreme Op Amp V5. It's a huge leap in sound quality-pick an adjective-than any of the ic chips mentioned. I tried them all, obsessive tweaker that I can be! I don't have a horse in this rate, I just want to share my experience with you.

I'm sure you're right , I just can't afford these ATM , and besides , if I didn't try the others I probably wouldn't appreciate the difference as much - it is fun , after-all .
 
Did you try other discrete options ? Like Sparcos or Sonic Imagery ? Just wondering , for when I can afford to go these routes ( nothing like positive thinking , hey ? ) .

  Speaking of Texas Instruments®, I read of other dual audio amplifiers that might be suitable for line-level buffer.  We know about the National Semiconductor® LM4562N, LME49720NA and LME49860NA.  But additionally, the Brown-Burr® OPA1642 has a mild 11 MHz gain-bandwidth product, 20 V/μS slew, and 5.1 nV/√Hz noise figure; the OPA1612, a 40 MHz gain bandwidth product, 27 V/μS slew, product and 1.1 nV/√Hz noise figure.  Both OPA's can go rail to rail at the output and are safe to 36 VDC supply.

I've tried LM4562N, LME49720NA in the buffer , but still prefer LM6172 . I've only tried OPA1612's in the I/V section , and must say they are of the best there , I've got LME49990MA's in the I/V now ( right up there with OPA1612 in this position ) , so I could try OPA1612 in the buffer now . I'll report back re OPA1612 in buffer .
 
I have to mention that I de-soldered a OPA2134 in my phono-stage and inserted opamp socket with OPA1612 there - simply amazing , clean , crystal-clear highs with pin-point definition , excellent seperation .  You got me wondering about OPA1642 now .

 

[illusiveart]

New Asus Essence STX skin for audio center!
http://stxiiskinmod.blogspot.com/p/audio-center.html

 

[gug42]

Anyone try AD827SQ in I/V with STX ?