Best op-amp transistor

[Gab]

What is the best ?
I think it is the combo : cirrus logic receiver + DAC +
burr brown dual monos 627BM

ANyone knows better chip ?

[Feanor]

What is the best ?
I think it is the combo : cirrus logic receiver + DAC +
burr brown dual monos 627BM

ANyone knows better chip ?

I don'd have the techincal savy to answer this question. What's more, I can't think of any regulars are AR who might. A good place to ask would be at ...
http://www.diyaudio.com/

[E-Stat]

What is the best ?

Depends upon the application. The OPA627 is a high bandwidth op amp designed for instrument use in the 400 khz - 1 mhz range. For audio use, the OPA2134 family is arguably better suited (and less expensive). Certainly, it is more commonly found in high end gear. Some folks prefer the new National Semiconductor LM4562 instead for audio circuits.

rw

[Gab]

Hey , thanks for the reply i checked the specs comparisons for fun
i would take the 627 as the winner, specialy because it is faster, making subtile sounds amplified perfectly, as well as large frequencies.
opa2134pa

bandwidth : 8 mhz , 20 V / ns
noiseL 8nv square root of frequency
gain: 120 db/600ohm
distorsion : 0. 000 08


opa627bm

bandwidth : 16 mhz 55 V/ ns
noise 4.5nv sr frequency
others: gain vs frequency in closed and open loop, looks like there is 5 db more than the 2134 chip. the opa637 was even better, like 10 db more than opa627
gain: 120 db
distorsion : 0. 000 03

WInner : opa637... anyone got that in there dac or pre amp ????? ops 627 is quite close, and LM49720 is a good alternative to opa2134, it is less expensive i think.


!! i checked the LM49720, supposed one of the best for fun :
bandwidth : 55 mhz 20 V/ ns
noise 2.7 nv sr frequency
others: gain vs frequency in closed and open loop, it is 15 db more than opa 627 , because of 140 db gain, but it drops faster, more frequency lag, its a slower chip and more dropping at low power high frequency inputs. Fast transcients : was like the opa2134, no slow transcients graphs was given , i might be wrong, there is like 40 graphs.
gain: 140 db
distorsion : 0. 000 03

[E-Stat]

Hey , thanks for the reply i checked the specs comparisons for fun
i would take the 627 as the winner, specialy because it is faster, making subtile sounds amplified perfectly, as well as large frequencies.

Beyond a certain point, however, there may be no difference. While there are some very nice DC to Light amps (Keith Johnson's Spectral designs come to mind), the very best audio amps in my experience (VTL Wotans, ASL Hurricanes, Audio Research REF series) are not super wide bandwidth designs. Realistically speaking, having bandwidth out to 1 mhz is simply unnecessary.

You'll find the OPA2134 in the GamuT CD-1, Gamut C2-R preamp, Emotiva amps, LInkwitz Orion crossover, Classe CDP-10 and Music Hall CD players.

rw

[Glen B]

The OPA627 is a high bandwidth op amp designed for instrument use in the 400 khz - 1 mhz range. For audio use, the OPA2134 family is arguably better suited (and less expensive). Certainly, it is more commonly found in high end gear.

Yes. Classé has used both the OPA627 and OPA2134 in their amps.

[Gab]

Yes its true that bandwidht is unecessary over even 20 khz but i tought it was one
way to determine the speed of the circuit.

For the transciens all chips had good graphs, 627 was the only one nearly perfect
others had little bumps on the attack and on the resolution.

For the large transciens all chip where curved graphs on the attack but the 627 had perfect decay, i dont know but these can make a difference when you add these defects
to the amp and the speakers. clearer is better imo = more perfect sound wave and better listening results. Ill have the chips soon and ill tell you if i hear a difference.