Here are the key differences between a preamp and an amplifier:
Preamp
- Boosts weaker signals like those from microphones and instruments to line level
- Usually the first component in the signal chain
- Found in recording studios and high-end audio systems
- Goal is to amplify without adding noise or distortion
Amplifier
- Boosts line level signals to speaker level
- Usually the last component before speakers
- Found in live sound reinforcement and home audio
- Adds gain to drive speakers, often coloring the sound
Other Differences
- Preamps have high input impedance, amps have low output impedance
- Preamps use voltage gain, amps use power gain
- Preamps focus on noise reduction, amps on high output
- Preamps have lower gain than amps
- Preamps don’t require as much power as amps
In summary, preamps prepare a signal for further processing while amplifiers drive speakers. Preamps are focused on fidelity while amps drive signals to high power levels, often intentionally coloring the sound. The two work together, with the preamp feeding signal to the amplifier in most audio systems.
Citations:
[1] https://musicaroo.com/preamplifier-vs-amplifier/
[2] https://www.musicianwave.com/preamplifier-vs-amplifier/
[3] https://higherhz.com/preamp-vs-power-amp-difference/
[4] https://primesound.org/amp-vs-preamp/
[5] https://forum.audiogon.com/discussions/sound-quality-impact-preamp-vs-power-amp
[6] https://theproductanalyst.com/preamp-vs-amp/