[smengy1]

Well I have done a bunch of recording with my Auzentech Meridian 2.1g and it sounds incredible with the dual LME 49710HA s in it!!!

I use Foobar for playback and it gives really excellent results.  Still the 49710's are harsh in the treble department.  I did not use a "flat"
RIAA curve when recording.  I used the bass and treble on my pre amp to add in bass and treble to my liking.  In the Auzentech controll
panel there is a thing called Bass Extender or something like that where you controll the crossover point.  It adds sweeteness to the treble.
Still the Ortofon x5-mx extracts alot of treble detail!    So I was looking for a mellower opamp.
 
Now I am split between OPA637AM and a OPA2111(both are to-99's).  I was wondering with the 637AM if it is better sounding than a AU per se,
and better than a opa2111.  I have also heard it said the opa637sm's are really harsh sounding.  I really enjoy the soundstaging of the LME49710HA's tho,
  what opamps in that LME family sweeten the sound up??
 
I found a site where they said the AM HA etc were ratings,  the A's being the worse and the H's better quality.   I wish I could find it again
so I could post the link.
 
I do love the sound of the LME49710HA's tho!   The soundstage is very 3d.  When I switch to Digital processing on the Audio card,  the
sound does warm up a bit,  and add in the Bass Crossover thing and its very nice.  Still the Analog section really has the best quality sound.
It is just drier and less warm than the digital processing. 
 
I was also thinking of buying one of these to put on the line to the amp. 
http://secure.oatleyelectronics.com//product_info.php?products_id=922&osCsid=75d0cc0ac13f60577205ee57ec321aaf
 
Here is a neat headphone kit too:
http://secure.oatleyelectronics.com//product_info.php?products_id=885
 
OK opinions please!!!!!
 
Oh and let me add,  I dont listen with headphones!!!  I know this is headphoner site,  but still you are only people talking about opamps,  so here i be!!!!

 

[ecohifi]

Quote:

you need x2 per adapter, check ebay, they make it for you. There are a few sellers. 
 
also the 49860 is based on the 49720, which is flawed. they are cheap upgrades though. but not in the LME49990, AD797, THS4032 range.

Please claify how the 49860 is based on the 49720 and that it is flawed???? 

 

[PurpleAngel]

Quote:

Please claify how the 49860 is based on the 49720 and that it is flawed???? 

The LM4652, LME49720 & LME49860 are the same op-amp.
When the LME49720 is tested at the factory and the op-amp can handle a greater voltage range, it's labeled a LME49860NA.

 

[majkel]

Please claify how the 49860 is based on the 49720 and that it is flawed???? 

The LM4652, LME49720 & LME49860 are the same op-amp.
When the LME49720 is tested at the factory and the op-amp can handle a greater voltage range, it's labeled a LME49860NA.

Yeah, sure. And when it gets fried, it's labeled LME49720. Please.

 

[zilch0md]

I don't know if that's true, but it's analogous to how Intel used to rate the clock speeds of their processors, back in the early days of Intel's x86 processors.  
 
I know that companies like Northgate, who were selling "IBM clones" would pay Intel more than the price of a 386-16 processor, for reject 386-20 chips that could be clocked at 18 MHz (but not quite 20 MHz).  Northgate would sell their machines as 386-16 machines, but they would clock the CPU at 18 MHz and thus, their machines would benchmark as being much faster than the typical 16 MHz machine.  
 
They were doing this BEFORE Intel officially released the 386-20 (by putting reject 386-20s on their motherboards and marketing their machines as the world's fastest 386-16s).  Later, when Intel finally worked the kinks out of the 386-20 design, actual 386-20 CPUs hit the market, and Northgate repeated the strategy, buying Intel's next rejects, but marketing them as "faster" 386-20's.  (Then the 25, the 33, and the 50...)
 
This was no secret.  Anyone who opened a Northgate machine at the time could see the 386 CPU, silk-screened with the markings of the next generation of chip, but with a permanent marker text applied by hand:  "18 MHz" (on a chip silk screened as a 386-20, for example - at a time when 386-20 machines were not yet being sold).
 
Mike

 

[FritzS]

What did you think about LME49713HA as driver? They easily drives 150Ω loads. Two LME49713HA in parallel should drive the most headphones.
 
Have anyone experience with Analog Devices AD815AYS (headphone driver), TI OPA1632, TI OPA1612?

 

[qusp]

cant really remember ad815, but plenty of experience with opa1612 and opa1632. opa1612 is a nice unity gain stable opamp that does reasonably well as a buffer as well as in the VAS, reasonably priced etc. if using it alone its the better choice, but if there is a buffer afterwards to drive the headphones, or you are using them for line out, driving fairly high load impedance; then I would choose the newer opa1642, it doesnt have much current capability though so wont do well with low impedance loads.

the opa1632 is a fully differential balanced in, balanced out super symmetry opamp, an excellent chip, but wont work in place of the others, or in any of these designs even if balanced, unless you modify the PCB. its a fantastic chip when suitable and I use it extensively, but its not any good for opamp rolling because of this.

the rumour of these chips all being the same is just that, rumour, the spec is similar and they are made with a similar process but thats where it ends. the rumour was started by someone who left National long before they were acquired by Ti and was later denied by another employee, but it has spread throughout the net, repeated by people who dont have any way of knowing one way or the other.

@smengy
not sure where you may have read about a comparison between any HA suffix and an SM suffix, thats funny, if you did the person was talking out their ass … They are simply suffixes to describe grading and physical package (metal can to-99, DIP8, SOIC8 etc) HA and SM are metal cans from different companies, well not now, now national has been acquired by Ti. HA is one suffix used to signify a metal can part designation from National; SM or AM is a metal can suffix from Ti (SM is the highest grade milspec). SM harsh and the soic not? lol why must people persist in making stuff like that up:rolleyes:

 

[ecohifi]

Quote:

cant really remember ad815, but plenty of experience with opa1612 and opa1632. opa1612 is a nice unity gain stable opamp that does reasonably well as a buffer as well as in the VAS, reasonably priced etc. if using it alone its the better choice, but if there is a buffer afterwards to drive the headphones, or you are using them for line out, driving fairly high load impedance; then I would choose the newer opa1642, it doesnt have much current capability though so wont do well with low impedance loads.
the opa1632 is a fully differential balanced in, balanced out super symmetry opamp, an excellent chip, but wont work in place of the others, or in any of these designs even if balanced, unless you modify the PCB. its a fantastic chip when suitable and I use it extensively, but its not any good for opamp rolling because of this.
the rumour of these chips all being the same is just that, rumour, the spec is similar and they are made with a similar process but thats where it ends. the rumour was started by someone who left National long before they were acquired by Ti and was later denied by another employee, but it has spread throughout the net, repeated by people who dont have any way of knowing one way or the other.
@smengy
not sure where you may have read about a comparison between any HA suffix and an SM suffix, thats funny, if you did the person was talking out their ass … They are simply suffixes to describe grading and physical package (metal can to-99, DIP8, SOIC8 etc) HA and SM are metal cans from different companies, well not now, now national has been acquired by Ti. HA is one suffix used to signify a metal can part designation from National; SM or AM is a metal can suffix from Ti (SM is the highest grade milspec). SM harsh and the soic not? lol why must people persist in making stuff like that up:rolleyes:

Nice down to earth post qusp,
Why does it always take someone from downunder to reafirmed the truth?
 
Regards
 
echohifi
(Posting from Guandzhou China on holidays but reside in Melbourne Australia)

 

[smengy1]

WEll look what I found,  the "Quality"  grading i was talking about.  Ahh who knows if it means anything
 
i had asked them directly about the difference in their 637 models, the $70 vs the $250, and heres what i was emailed back about the product codes-

"The first letter, A','B','S' means OPAMP Grade' and the quality is better in following order.
A' < B' < S'
The second letter, U','M','P' means package type'.
P: DIP type
U: SMD(SOIC-8) type
M: Metal Can type(It protects against the noise and electricity)
The 637 line's feature is similar, but the quality is different.
Therefore the OPA637SM type is the highst price as the best sound quality."

so i have the 637au which came out two months ago, and this past week they have the new 637sm now for 4x the price. i wonder who will ever be able to compare the two with a good system. i run my prelude into the rotel 1085 5ch digital amp and wonder if there would be any difference.
 
So can anyone reccomend anything warmer and detailed and nice Bass for a Auzentech soundcard?
 
I have LME49710 HA?
 
Ignored as usual. 

 

[kiteki]

Err, they are some pretty high prices there for the OPA627 variants.  Yes, it's a very popular chip with due reason, it's not amazing though, and I find that other chips have nicer highs, there is some kind of veneer on the highs of the OPA627, it's like it's 'painted' and can't break free into an open sky, it's annoying once you notice it (unless I'm just not supplying it with the right DAC or +-15V or whatever it needs).
 
The OPA827 and OPA1612 are nice and neutral chips while sounding analog at the same time but they don't have any character like the OPA627 has, they sound like empty hospitals, honestly.  Chips with character plz.

 

[FritzS]

Now I use two OPA627  in my (old but good) WNA MKII headphone amp, with best results
 
You can see here all the OPA's I test
http://www.head-fi.org/t/99596/new-wna-mkll-head-amp-kit/750

 

[kiteki]

Originally Posted by
 
AD797.

 
 
Keep in mind AD797ANZ and AD797BR sound quite different........................................
 
Currently, I'm finding the latter excellent as a line-out driver.
 

---

 
 
This DAC has me curious, it's using ESS ES9018 in current-out mode, can I connect the line-out on it directly to my amplifier without issue?  Any flaws it may have?  http://www.audio-gd.com/Pro/Headphoneamp/NFB11.32/NFB11.32EN.htm

 

[kiteki]

Now I use two OPA627  in my (old but good) WNA MKII headphone amp, with best results
 
You can see here all the OPA's I test
http://www.head-fi.org/t/99596/new-wna-mkll-head-amp-kit/750

 
It's a fantastic op-amp, perhaps one of the best ever made, however right now I'm preferring the more pristine unfettered highs of the AD823!

 

[FritzS]

Quote:

 
It's a fantastic op-amp, perhaps one of the best ever made, however right now I'm preferring the more pristine unfettered highs of the AD823!

 
I am going the reverse way in my GSP Audio Solo, I use a metal can OPA LME49720HA instead of the AD823 with better performance.
 
Otherwise in WNA MKII I had with LME49710 not the best results.

 

[kiteki]

I suppose OPA627, AD823 and LME49720 etc. will sound a little different in different amplifiers, due to buffers, capacitors, circuit layout, voltage supply and that jazz... but how about the sound of the DAC and the line driver before the amplifier?
 
...only AD797BR as the line driver really unlocked the potential of AD823 for me !!
 
 
Hmmmm I'm wondering if the ESS ES9018 in current-out mode could be a nice alternative for DAC and line-out to amplifier fun?