the buzzing from amplifiers

[annolsen2009]

Hello,everyone!
I'm feel confused. How to judge if the amp sound good enough ?

Someone tell me judge whether the amp is well constructed by turning off the source and listen for noises from the amp.

Do you have any kindly advice.Thank you very much.

[weinstro]

Hum and buzz problems are distinct from amplifier distortion characteristics.

The former will depend on your power circuitry, type of interconnect, and how the grounding was setup in your system. Hum problems can originate from the amp, preamp, source, or even cable/satellite feed.

The latter depends on the amp design and execution.

[richwalters]

I treat chassis buzzing and mains transformer line frequency noises as sound /listening distortion as they can be distractive at listening levels. That's why I often make a small subframe then mount mains transformers on rubber grommets. The shroud lid gets the same treatment and is suprising what reduction this can make. Dunking the core with extra varnish may also be required. It seems pointless designing for a fantastic low noise spec when the magnetics is going to ruin it.
Becareful,; make sure shroud and safety earth continuity is maintained.
In general, only the power VA mains transformers with relatively high magnetic excitation should need this.

richy

[richwalters]

For those wanting more, Farnell and other good hardware cat/ do various vibration mounts, dollies and so on. pic encl. The 5/6 mm thread size are good. Bear in mind portability, they wont take alot of side shear and allow longer wiring. No different when moving house to adding braces to a washing machine.

richy