OPA134PA Vs. TL071

[VanWhy]

In anyone's experiences, has the OPA134PA made a difference in a circuit? I can't imagine there would be anything noticeable but just curious what the forum thinks.

For reference, I'm getting ready to build the Superflare fuzz which uses the OPA134PA.

 

[benny_profane]

I don’t see the point in putting a low-noise audio amplifier in a fuzz circuit. I’d say the TL071 would be perfectly fine.

 

[passtheducky]

I don’t see the point in putting a low-noise audio amplifier in a fuzz circuit. I’d say the TL071 would be perfectly fine.

I hear this a lot but I think it’s questionable. A fuzz or a distortion can have huge amount of gain and reducing hiss is a reasonable goal for some designs, even if the input waveform will be mangled to hell and back by clipping diodes and what not.

That said, TL071 is already low noise enough for most cases.

 

[benny_profane]

You won't reduce hiss if it's present at the amplifier input. The OPA134PA will have better THD performance than the TL071 amplifying that hiss from earlier stages more faithfully, I guess. Both devices are high speed (20 and 13 V/µs slew rate, respectively), have adequate bandwidth (8 and 3 MHz), and have the same CMRR figure (100 dB). Neither are rail to rail devices, so headroom is comparable. The big advantages of the OPA134PA seem to be the better THD and noise figures. If hiss is a concern, I think a LPF at the output stage would be a better design direction than an overspec'd part.

 

[JTEX]

I took a quick look at the Superflare circuit and I don't see how an OPA134 would do any better than a TL071 that late in the signal chain, and this comes from someone who is not really a fan of the TL07x series I'd save a few bucks for a beer.

 

[VanWhy]

I took a quick look at the Superflare circuit and I don't see how an OPA134 would do any better than a TL071 that late in the signal chain, and this comes from someone who is not really a fan of the TL07x series I'd save a few bucks for a beer.

I like the way you think