Here are some key factors that affect the sound quality of an amplifier:
Distortion
- Total harmonic distortion (THD) – Lower THD means less added harmonics and coloration. Under 0.1% THD is generally very good.
- Intermodulation distortion (IMD) – Causes unwanted mixing of frequencies. Lower IMD gives better clarity.
- Noise – Hisses, hums, and buzzes add an unwanted background. Higher signal-to-noise ratio (SNR) reduces audible noise.
Frequency Response
- Wider, flatter frequency response reproduces more audio content accurately.
- Rolled off highs or lows will lack sparkle or bass. ±0.5dB is excellent.
Power
- Adequate power prevents clipping and allows speakers to reproduce dynamics. Underpowered amps distort more easily.
- Headroom above actual use levels gives amps room to handle peaks cleanly.
Damping Factor
- Higher damping factor gives an amp better control over speaker behavior for clear, tight bass.
Inputs and Gain Structure
- Clean signal path from inputs to power stage prevents noise and distortion issues.
- Proper gain staging optimizes each stage for minimal noise and maximum headroom.
Design and Components
- High-quality parts like capacitors and resistors impact distortion and noise floor.
- Overall circuit design approach affects distortion profile and sound signature.
Citations:
[1] https://hificentre.com/blogs/news/does-an-amplifier-improve-sound-quality-an-in-depth-analysis
[2] https://sound-au.com/amp-sound.htm
[3] https://allforturntables.com/2023/06/30/does-an-amplifier-affect-sound-quality/
[4] https://audiosciencereview.com/forum/index.php
[5] https://www.musicstreet.co.uk/blogs/blog-post/factors-to-consider-when-you-are-buying-an-amplifier
[6] https://www.cambridgeaudio.com/usa/en/blog/amplifier-specifications