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最初由 MONO 发布
GOOGLE了一下
OPA 134有介绍吗？:D
Burr-Brown OPA134
Cost, single: n/a Vmin, 0.5V into 33 Ω: 5.7V
Cost, dual: $2.63 Vmin, 2.0V into 330 Ω: 8.4V
This is the audio grade version of the OPA132 family. (That's "audio grade" in the commercial sense, not the audiophile sense. Read: "lower quality".) Digi-Key only carries the dual version (2134) in DIP packages.
The OPA134 requires a bit more voltage than the OPA132 does. This won't matter in circuits that have plenty of voltage, but in a battery powered system a 132 can pay for itself by letting you run longer on a battery.
I found in earlier testing that the 134 was more likely than a 132 to become unstable in marginal circuits. Sometimes raising the supply voltage was all it took to make the 134 stable, and other times only swapping in a 132 would fix the problem. If you're building your own circuit from scratch and you aren't very experienced, the extra cost of the 132 can pay for itself in a better likelihood of success.
Bottom Line: If your circuit is solid and you have a fairly high supply voltage, the 134 is better than the 132 because it's cheaper and they sound identical to me. The 132 is better for more marginal setups.
Burr-Brown OPA627
Cost, single: $18.38 (OPA627AP) Vmin, 0.5V into 33 Ω: 6.8V
Cost, dual: n/a Vmin, 2.0V into 330 Ω: 9.8V
The first thing I noticed is the cleanliness of the sound. With this chip in the test amplifier, I heard known problems in a low-end portable source more clearly than with my reference for this test, the OPA134PA. The 627 also seems to do better on recordings with room ambience: it reveals details about the acoustic space that the OPA132/134 chips will hide, making them sound "flat" in comparison. But these two chips are more alike than different. Both have the characteristic laid-back and dark Burr-Brown sound, and both are very tolerant, stable chips.
The only remaining differences are that the OPA132/134 family will work well below 9V, whereas the 627's performance falls off a cliff below the clipping points I give above. There does seem to be a bit of extra low bass impactfulness with the 627. This seems less to be "extra power" than a removal of some heavier thumpiness in the 132/134 — the 627 seems to have a truer, more refined kind of bass.
In all my testing, I've been unable to hear a difference between the OPA627AP and the OPA627BP. The datasheet says that the differences between the grades are in the DC specs, so this is not surprising.
Bottom Line: The sonic differences between the OPA627/637 and the OPA132/134 are of the "last 5%" variety, rather than providing a dramatically different sound. If you like the Burr-Brown sound and can stand to pay 14× as much as for an OPA2134PA, a pair of OPA627APs is a reasonable investment. I see no reason to pay extra for the B grade in an audio application.
摘自：
http://tangentsoft.net/audio/opamps.html
