[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.

 

[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.

 

[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.

 

[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?

 

[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.

 

[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

 

[Filburt]

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

 

[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.

 

[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.

 

[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.

 

[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.

 

[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.

 

[majkel]

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

 

[deuginthesky]

Have you listenned both ?

 

[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.