# LME49710 vs OPA627s ?



## deuginthesky

Hello all,


 I have used with greats results OPA627s (AP and BP) in DAC outputs and CDP outputs, I have recently switched to LME49710 and find them better.

 Is my opinion shared here ?


 Regards.


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## Atchoum

I totally agree !
 in my yulong the 49710 sound better to my ears than the 627bp : better highs, cleaner bass, definitly more transparent. the 627bp have more bass weight, maybe a slightly better bottom extension but do not sound "as true" as the lm49710.


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## bigcat39

Hmmmm. I find opamps to be very much a matter of taste, However, there is no opamp that I know of that is faster than the OPA627. Speed being a virture and all. Looking at the specs, the slew rate of the OPA is more than twice as fast as the LME49710. I prize precision in a solid state amp. (shrug) YMMV.


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## n4k33n

I just opened my ppa to change the opamps to the ad8610 and found the center was a 627ap. how is that different from the bp?


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## error401

It's a different 'grade' of the chip. The 'B' grade has slightly better specifications across the board. 'A' is probably 'audio' grade, which in opamps is usually the inferior model. Check the datasheet for details.

 It seems like it's about $10 cheaper per unit.


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## wquiles

Quote:


  Originally Posted by *error401* /img/forum/go_quote.gif 
_It's a different 'grade' of the chip. The 'B' grade has slightly better specifications across the board. 'A' is probably 'audio' grade, which in opamps is usually the inferior model. Check the datasheet for details.

 It seems like it's about $10 cheaper per unit._

 

Yep, those are exactly the differences that I found as well.

 Will


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## Filburt

'A' is just TI's designation for the lower spec variant; I don't think it is in reference to 'audio.'


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## majkel

B means tighter DC specs than A which is meaningless for audio. 

 Regarding OPA627 "speed" - what's that unique application? Wherever I use it, it's laid back and rather "slow", not as snappy as most AD's.


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## bada bing

Quote:


  Originally Posted by *bigcat39* /img/forum/go_quote.gif 
_Hmmmm. I find opamps to be very much a matter of taste, However, there is no opamp that I know of that is faster than the OPA627. Speed being a virture and all. Looking at the specs, the slew rate of the OPA is more than twice as fast as the LME49710. I prize precision in a solid state amp. (shrug) YMMV._

 


 OPA627 & OPA637 are only moderately fast opamps:
 OPA627 = 55V/uS
 OPA637 = 135V/uS

 in contrast a LT1364 is rated at 1000V/uS

 Slew rate doesn't tell everything. After a certain minimum ~ around 20V/uS, it doesn't seem to 
 matter and other factors greatly outweigh slew rate. To my ears OPA627 is a much preferable
 opamp to the LT1364.


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## majkel

The slew rate says nothing about sonic abilities of a certain op-amp. All of them, even "slow" OPA2111 have enough slew rate for audio. Talking about punch and speed - AD843 is rather slow spec-wise, but more snappy sounding than most BB's.


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## deuginthesky

OPA2227 is also a nice opamp, although it is very slow.

 To focus on which you prefer between LME49710 and OPA627 only please, people who tried both in the same configuration, which one would you keep ?

 Regards.


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## dumbears

Just my 2c.

 I prefer LME49710 to OPA627 in many aspects. Not only is it sound better, it's also more battery friendly. However, I've issue on its higher DC offset. The other opamps don't have the "roller coaster" phenomenon on DC offset.

 I wonder if it's only my issue. Perhaps, I'm too mean.


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## majkel

Given just these two, I'd choose the OPA627, if only LME49710 is a single version of LM4562.


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## deuginthesky

Have you listenned both ?


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## majkel

I've listened and owned OPA627, LM4562 and many others. LME47910 - not but people say it's a single LM4562. If you need a decent single - LT1028 (not working at the gain of 1), AD825, LT1363, OPA211... OPA627 still OK.


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## deuginthesky

LME49710 is the single version of the LME49720 which is to me the same as the LM4562.


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## majkel

LT1028 is more transparent than the LT1363, and I've learnt how to make it stable at gain of 1, even without additional capacitors. it's described in the datasheet.


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## deuginthesky

Quote:


  Originally Posted by *majkel* /img/forum/go_quote.gif 
_LT1028 is more transparent than the LT1363, and I've learnt how to make it stable at gain of 1, even without additional capacitors. it's described in the datasheet._

 

Heard LT1028 and LME49710 on same CDP (tweaked philips) , I prefer the LME.


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## deuginthesky

Not precise enough, noisier, less realistic to me.

 Colors and tastes...


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## majkel

RFL - try AD825. I liked the LT1363 for a couple of days but it's too blurry and congested for me. Too much warmness. AD825 after a year still amazes me sometimes. It's a pleasure oriented op amp.


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## deuginthesky

Quote:


  Originally Posted by *RFL* /img/forum/go_quote.gif 
_Perhaps you haven't used it correctly. The LT1028 has such a low (lower than that of the LME49720) specified noise voltage that you would have bionic hearing 
	

	
	
		
		

		
		
	


	





 Regarding tonality, the LME49720 is cold-blue whereas the LT1364 is warm-yellow. I like warm colors. The LT1364 absolutely doesn't lack transparency, but it's not boringly clynical which I like for sure. They actually work very well together, one after the other in the audio path._

 

I was mostly talking about the LT1364. I know LT1028 is one of the lowest in the market.

 I have better details with the LME49710, difference is bigger with my 24-192 DAC than with CDP (use 2X LME 49710 and 2X LT1028 on a brown dog adaptater).

 Heard the AD825 too, not woth a double 627AP which is under the LME49710 to me.


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## Henmyr

Is there a reason to use single op-amps instead of duals? For exemple 2x LME49710 on brown dog adapter instead of LME49720.


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## majkel

LT1360 looks like a lower biased and therefore slower LT1363, so it probably sounds worse overall. Actually, different op amps work in different applications better. Let's better not make a general op amp discussion of this thread because there is lots of other existing.


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## majkel

I have a proper supply decoupling and I'm waiting for the LT1360 and LT1357 samples actually. IIRC, the LT1469 has been ordered as well. 
  Quote:


 Let's not be too rigid, too. Opinions evolve. 
 

I was saying you can revive other threads where you can find interesting assumptions about AD8599, AD797, AD8021 and others. For instance, I prefer the AD8599 to the LT1364, both are warm but LT1364 hasn't got top notch trebles. AD8022 is another very good dual chip with no single equivalent, etc.


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## deuginthesky

Quote:


  Originally Posted by *Henmyr* /img/forum/go_quote.gif 
_Is there a reason to use single op-amps instead of duals? For exemple 2x LME49710 on brown dog adapter instead of LME49720._

 

Less offset, less noise and less bias.


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## mnemoniak

hey here, I'm looking for OPAs for my prodigy HD2, i'm using x3 LM4562 for now, instead of the x3 5532 on the original board, it's way better, really, but, i'm looking for something else, the same 'power' but with better mids and lows, voices sounds very cold and distant, I think i'm gonna buy the LT1364, 
 my questions to you OPA experts is, will I need 3 of them ?

 And, are the :
 "LT1364CN8#PBF Dual 6mA 70MHz 1000V/uSec OA PDIP" 
 from the Linear Technology website the ones I will need ?


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## mnemoniak

Thank you RFL, I need DIP, so, I will buy the CN8, three of them, $4.58 each, I can't go wrong.


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## majkel

The best PROVEN combination for Prodigy HD2 is 2x OPA2604 + AD8022, period. I know, the guys haven't tried the LT1364 but I'm still not expecting it to be better. Cascading the same op amps can't produce best results as the same sonic effects get emphasized, instead of some sonic compensation and synergy.


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## sleepy dan

Hello deug,

 I like the LMs too. Haven't compared them to OPA627s, but have done so with LT1364s where the LMs are clearly more transparent.


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## mnemoniak

OK, thank you for your advice majkel, I Already heard OPA2604, it was with 2x OPA2134, I still prefer 3x LM4562,
 considering I never heard the 2xOPA2604+AD8022 combination, plus , considering I caught the Head-fiing virus, I will plan to buy 3x8022, 3x2604, 3x1364, I think it will be LT1364 at first.

 PS : sorry for this out of thread Parenthesis


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## mnemoniak

In fact, I don't really get it, what each of those amps are doing, on the card, one amp is in front of the two others which are in line, on the HD2 advance, there is one 2604 and two 2134.


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## majkel

I was unprecise. The LT1264's sounds are not blurry, it's imaging is a bit blurry, not so precise. I know why people like it and I understand it but above some quality level this op amp's signature becomes a bottleneck for the device. However I'm not sure it will be the case with the HD2. Regarding the LM4562 - the guy who told me about the OPA2604 + AD8022 results, also tried this combination. LM4562 is a bad op amp, especially would be for the LT1364 fans. Actually, for spectacular effects you need to mix two different op amps and include proper supply bypassing capacitors' choice.


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## majkel

Quote:


  Originally Posted by *headsocks* /img/forum/go_quote.gif 
_LOL! So you're saying that because imaging "is a bit unprecise" it will become a bottleneck? Well, that's pretty personal at least. And I thought that the LT1364's presence (which is how I'd call it) was a wonderful thing, period._

 

There is nothing like wonderful presentation of an op amp. I hope you'll realize this some day. LT1364 might do the trick but I heard much better combination than LT1364 alone, and not involving the LT1364. It's a good op amp indeed, but I prefer the AD8599 to it, being somewhat similar.
  Quote:


 I don't know if it's a "formally perfect" representation what you're looking for, but me, what I'd look for in high-end audio would eventually just be more emotion. That's what music is supposed to be about. 
	

	
	
		
		

		
			




 

So, believe me, it was to few emotions for me from the LT1364 and that's why I moved to other solutions. Unfortunately unfeasible in the HD2.
  Quote:


 Regarding the LM4562, the (better) LME49720 is nothing like a bad opamp. It's just a little cold sounding without too much presence - that's why it works wonderfully with the LT1364 (one after the other). The resulting sound is very very convincing, believe me. 
 

I would never believe a midrange color killing op amp like LM4562 could sound good anywhere. Huge bass, overephasized articulation and cold, grey midrange - that's it. All the LT1364 can do is warm up and colorize the midrange but I don't believe this is true timbre instead of LT1364 timbre. 
  Quote:


 Finally, regarding the OPA2604 - is it really that good? I haven't thought so since I replaced it with a TI 5532 in a Rotel RCD950 and the 5532 sounded more precise. 
	

	
	
		
		

		
		
	


	



 

Why do you replace a bipolar input op amp for a FET input op amp? You don't need doing this. You can find my posts in this forum where I say that I prefer the bipolar op amps if only I can use them because they are more transparent IMHO.


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## majkel

I didn't know the LME49710 sounds different from the LT4562. Everybody reports it's the same, just single/dual difference. 
 OPA2604 is my favourite *FET input* op amp, and I cannot use a bipolar one there due to high input currents. It's I/V stage in my CDP. If I don't have to - I don't use OPA2604 neither any other FET input op amp. And it's not great alone but paired with another one, i.e. AD8022 - sounds good. 
 Regarding emotions - I don't think we call different things with this word, it's more probable we obtain different results due to different applications. I mostly tried the op amps in my CDP and preamp/headphone amp circuits. If the results repeat which I mean same sonic impact, then I think I know what the certain op amp sounds like. 
 If you haven't tried the AD8599 - please do and compare it to the LT1364. What I like more about the AD is cleaner, more delicate trebles, while preserving overall warm presentation. Imaging is slightly better as well.


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## majkel

LT1364 has got corrupted, unnatural treble timbre. Listen to some hit-hats, other percussion. There is a false tint. I understand your love (whoever I'm writing to now) for the LT1364 but other parts give better results in my system. I like it that you're happy with the LT1364 in yours, if you tell me AD8599 suits worse, I'll accept it and it won't change a single thing in my looking at sound. 
 Actually I think LT1028 is better, more transparent, but it didn't work either in my final solution. It's all about the synergy, so I can even accept the point of view that the LT1364 is best dual, where I'll still insist on AD8599's supremacy, and there is another, which has been my favourite single op amp for ages - AD825, try this as well. NelsonVandal reported that AD8599/AD825 combo is the most natural op amp combo for virtual ground headphone amps. This might be true.


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## jamato8

Try the opamp with a 20pf from pin 8 to pin 4. this is a bypass for the dc in and can clean up some of the white noise that can "corrupt" the sound. This is done right on the adapter board with the shortest leads possible. You can also try a .001. I used a 47uf HiQ Black Gate and a .47uF like this with good results.


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## mnemoniak

After having read advices here, I ordered samples of LT1364s, two is the maximum, i will test them with the LM4562 on my prodigy HD2, come what may, I can't try AD's8599, they are not in DIP-8 format and I am not able to put them on SOIC to DIP adapters.


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## GuyMe

Quote:


  Originally Posted by *majkel* /img/forum/go_quote.gif 
_The best PROVEN combination for Prodigy HD2 is 2x OPA2604 + AD8022, period. I know, the guys haven't tried the LT1364 but I'm still not expecting it to be better. Cascading the same op amps can't produce best results as the same sonic effects get emphasized, instead of some sonic compensation and synergy._

 

The AD8022 is not available as a dip, what other opamp could you reccomend in its place with the OPA2604?


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## GuyMe

Quote:


  Originally Posted by *XTC* /img/forum/go_quote.gif 
_LT1469, try it. Also try the [very transparent sounding] LT1361._

 

This lead me to do a few searches and I think 2xLT1364 and a LT1361 might be the best combo for me. Thanks for the tip.


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## jh4db536

the LME49710 is awesome for clarity, detail, and decongestion. I like it better than 627BP, AD8610 by a longshot.

 I think the LME synergizes perfectly with the HD6x0 and my HFI780. I HATE it with my 701. It has like zero bass impact and sounds way too thin.


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## d-cee

I just got the LME49710s and installed them in my PPAv2

 Compared with OPA627 they are a cooler sounding opamp

 IMO the OPA627 are very detailed but not in your face so, the LME49710 with its more upfront presentation seems a bit more detailed but I'm yet to be decided.

 Slightly prefer the OPA637 w/ OPA627 in ground. 

 Still overall prefer best the comp pin out of the AD744 w/ AD829 in ground.

 These impressions are based on a PPAv2 so YMMV.


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## kunalraiker

Quote: 





jh4db536 said:


> the LME49710 is awesome for clarity, detail, and decongestion. I like it better than 627BP, AD8610 by a longshot.
> 
> I think the LME synergizes perfectly with the HD6x0 and my HFI780. I HATE it with my 701. It has like zero bass impact and sounds way too thin.


 


 I would agree on this, found the soundstage to have more depth on my Grado's,the OPA604's did have more speed.


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## ROBSCIX

I am a fan of the LME49710, usually opting to use dual LME49710HA's over dual channel chip version such as the LME49720.  I do like the TO-99 version over the DIP or SOIC versions.


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