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OK audio gurus: What are the highly regarded FET-input op amps these days?
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cvanc:
This question is triggered by a repair I recently did where the originals, while still available, were stupid expensive.  It occurred to me that a more modern & higher performing part must exist at a lower price - a win-win scenario if ever there was one.

Due to the circuit specifics it needs to be FET input, and also unity gain stable.  I have not kept track of this category since the LF411/LF412 were considered the good stuff.  Surely there's something better by now?

Thanks.
floobydust:
It's not that simple, you have to consider what the op-amp is seeing and doing.
Line driver? Tone controls? DAC reconstruction filter?

The better FET-input op-amps are expensive because they are laser-trimmed and prices can be crazy.

I would recommend OPA2134 or OPA134 and if you have money the OPA627 or OPA637. But $40-57 each :o

Careful swapping in a higher bandwidth part, they can oscillate in "old" circuit designs and not all parts are unity-gain stable.
Zero999:

--- Quote from: cvanc on December 06, 2018, 05:37:55 pm ---This question is triggered by a repair I recently did where the originals, while still available, were stupid expensive.  It occurred to me that a more modern & higher performing part must exist at a lower price - a win-win scenario if ever there was one.

Due to the circuit specifics it needs to be FET input, and also unity gain stable.  I have not kept track of this category since the LF411/LF412 were considered the good stuff.  Surely there's something better by now?

Thanks.

--- End quote ---
Just replace the original op-amp with one with a similar specification, if it's not possible to find an exact replacement.

Old op-amps such as the LF412 and TL072 are more than good enough for 99% of audio applications.

Replacing the part with a more modern device could risk messing it up and ruining the performance so lose, lose. Newer so-called audiophile op-amps have a higher bandwidth, than the traditional ones, so are more sensitive to board layout and can easily oscillate. If a circuit isn't designed for such a high bandwidth op-amp, then blinding replacing the op-amp with a faster one is asking for trouble.
SiliconWizard:
Some references come to mind:
OPA2134
OPA2604
OPA1652
Conrad Hoffman:
A lot of new parts are only available in SMT, which can limit you unless you use adapter boards. The TI OPA164x series looks interesting.
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