Experiment # 1: Disconnect the speakers from an old radio
1. From an old radio disconnect the speakers by cutting the wires
2. Reconnect the speakers by joining wires: Still work? Good!
3. Connect another set of speakers in place of the ones you disconnected. Still work? Good!
4. Now time to build your audio pre-amplifier. This takes us to experiment # 2
Experiment # 2: Build a pre-amp
1. We're going to start off with something simple that will give us confidence to proceed. Go to this schematic and build it on the breadboard.
2. Connect the function generator sine wave input to this and see that you get a clean sine wave at the output: Done
3. Now connect the radio output to the input of this circuit and the output of this circuit to the speaker : Done
Some observations
1. Even though the output of the radio puts out a differential output signal, you can use it in a single ended fashion by grounding one of the inputs. A single output does just fine
2. You can even invert the inputs to the amp we built and it still sounds the same
3. If you want to use it in single ended fashion, sure you must ground one end. If you leave one end floating somehow, the channel seems to be different. Why?
4. Distortion observed as well. Saturation observed. Did not wanna do more as that would blow out the speaker.
1. From an old radio disconnect the speakers by cutting the wires
2. Reconnect the speakers by joining wires: Still work? Good!
3. Connect another set of speakers in place of the ones you disconnected. Still work? Good!
4. Now time to build your audio pre-amplifier. This takes us to experiment # 2
Experiment # 2: Build a pre-amp
1. We're going to start off with something simple that will give us confidence to proceed. Go to this schematic and build it on the breadboard.
2. Connect the function generator sine wave input to this and see that you get a clean sine wave at the output: Done
3. Now connect the radio output to the input of this circuit and the output of this circuit to the speaker : Done
Some observations
1. Even though the output of the radio puts out a differential output signal, you can use it in a single ended fashion by grounding one of the inputs. A single output does just fine
2. You can even invert the inputs to the amp we built and it still sounds the same
3. If you want to use it in single ended fashion, sure you must ground one end. If you leave one end floating somehow, the channel seems to be different. Why?
4. Distortion observed as well. Saturation observed. Did not wanna do more as that would blow out the speaker.
No comments:
Post a Comment