An op-amp buffer consider an amplifier section in a pedal?

[Yoshi]

Hello, Ive a question: An op-amp buffer consider an amplifier section in a pedal?

There are buffer that uses transitors and then there are buffer made with op-amps... the second one it can be considered a amplified section? or not?

Thanks

[MrStab]

If the op-amp has a gain of 1 or -1, then it's not an amplifier because it's not amplifying. It lowers impedance, which has an audible relationship with cable capacitance and treble, but it's not actually amplifying.

[Yoshi]

So ... there is a difference using an op-amp or a transistor?, there is a difference in sound for example?

[FiveseveN]

If the op-amp has a gain of 1 or -1, then it's not an amplifier because it's not amplifying.

It's amplifying current.

op-amp or a transistor?

False dichotomy. An operational amplifier is made with transistors (or other active devices).

[Yoshi]

So.... is correct too say that an op-buffer is an amplifier section?

[FiveseveN]

According to the sources cited on Wikipedia, yes.
"An amplifier is defined as a circuit that has a power gain greater than one"
So is the single-transistor one.

[antonis]

There is "Voltage" amplification, "Current" amplification and "Power" amplification..
(actually, none of the former two is sheer but let them be..)

e.g. A BJT CC amp (buffer or Emitter follower) is considered Power amplifier 'cause current amplification is larger than voltage reduction hence the output product of Current & Voltage is bigger that the input one..

[PRR]

A particular question: "will it distort?"

Wires, resistors, coils, and caps do not distort (much, at reasonable signal levels).

Tube and transistors (even hidden inside a chip) can always be made to distort.

There are other ways to get distortion (but many have hidden amplification around a passive clipper).

Amplifiers today can be cheap and nearly perfect (if you wish). Why count them?

Usually ONE amplifier in a signal chain dominates the distortion.

[ElectricDruid]

So.... is correct too say that an op-buffer is an amplifier section?

It's just a matter of terminology.

For me personally, an "operational amplifier" is still an amplifier whatever it's doing; buffering, filtering, whatever. You can set up an op-amp in the inverting amplifier configuration to have gain *less than* one, but it's still an inverting amplifier. It doesn't change into something else because you tweaked some resistor values. And that's true with the buffer too, which is really a degenerate case of the non-inverting amplifier configuration, where the feedback resistor has been reduced to zero ohms. At least in my head.

[merlinb]

Yes, a buffer is an amplifier section.

A discrete transistor buffer will usually measure more harmonic distortion than an opamp buffer, but either way it will likely be inaudible.