Headphone amp

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Why so many op-amp's in stead of a single buffer-chip with sufficient output power?

I suppose you consider the first op-amp (on the left side of the schematic) to act as a driver since it is connected differently than the rest? No need to use a "driver", if the input impedence is as high as a typical op-amp (don't know your particular chip).

Remember, headphones use fairly little power, so a lot of circuits should be able to do the trick.

Have you tried to simulate a circuit, which is basically a class-A buffer stage (voltage follower)? It seems to me that you're making life more complicated than it needs to be.

Jennice
 
The input impeadence to an op-amp is very high. The output impeadence is much lower. The only reason to use op-amps in this fasion is to put RC filters in between them to make an active filter network. You are attempting to lower the output impeadence of the op-amp circuit by parralelling the devices. There is a much easier way to amplify current. It is called an emitter follower circuit. (or source follower if you use a FET). Use one op-amp to drive the emitter follower stage which will drive the speaker or headphone.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.