iso audio transformers

Discussion in 'General Electronics Chat' started by electronewb, Jan 20, 2013.

  1. electronewb

    Thread Starter Member

    Apr 24, 2012
    I know how the basics of a transformer works but I'd like to know how an audio iso transformer eliminate a buzz or a hum in a audio signal?
  2. Veracohr

    Distinguished Member

    Jan 3, 2011
    It disconnects the source's ground from the destination's ground, breaking any ground loops between devices.
  3. electronewb

    Thread Starter Member

    Apr 24, 2012
    But what about if the source is already dirty or noisy?
  4. crutschow


    Mar 14, 2008
    It doesn't do anything to affect that.
  5. electronewb

    Thread Starter Member

    Apr 24, 2012
    So if it's dirty to begin it will stay dirty?
  6. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    Yes. A transformer isolates signals. The inductance may reduce very, very high frequencies (out of the audio range), but will not affect the signal. If it did, it would be adding distortion by removing signal frequencies.

    There isn't a way for a transformer to detect what is "noise" and what part is "good signal". Even Digital Signal Processing has difficulties removing noise from signal, unless the specific frequencies/amplitude of the noise are known.

    White/Pink noise is used in audio systems to equalize the various frequencies to be even based on the speaker response and room reflections. If any component or sub-circuit eliminated random noise, that method would not work.

    Common sources of noise in audio are introduced from the power supplies, impedance mis-matching, interference, etc. Good audio amplifiers are built to reduce the levels of created noise added to the signal from these in-amplifier sources to well below the actual signal amplitude so they cannot be heard at listening level.
    electronewb likes this.