0
\$\begingroup\$

I'm creating simple headphones amplifier with an opamp (basic non-inverting config with RC high-pass on NI) and I wonder, what's better - to control an amplitude of input signal, or a gain of an opamp?

What are benefits from gain control over signal control or vice-versa? Best regards!

\$\endgroup\$
2
\$\begingroup\$

Generally, you want to have the most gain at the beginning of your signal chain. The reason for this is that the noise added by the gain stages gets passed on and amplified by the next stage.

The downside to having too much amplitude before going into your opamp, is you may more easily saturate the inputs to the amplifier and cause clipping at a lower overall sound level.

Typically, however, you would design your circuit such that you control the amplitude before going into your opamp, so that you can make maximum use out of your total headroom.

\$\endgroup\$
2
\$\begingroup\$

If you're talking about volume control, typically this is done with a pot at the input. Normally changing the gain of an amplifier changes its frequency response; normally if you want that to change at all you want it to be controlled.

\$\endgroup\$
  • \$\begingroup\$ You're right, I completely forgot about bandwidth - thanks! \$\endgroup\$ – Endlesik Nov 19 '18 at 16:06

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.