I am building a 4 channel power amp. Each needs 2 x 25-30 VAC/ 100-120 VA. My plan is to use a single transformer and wire them all parallel. Would a 2 x 30 V/400 VA transformer do the trick?
I'm a total novice and want to avoid any disasters.
In general, if your load is X, and you have a supply that can provide X, then you are "good."
However, for highly current sinking applications like power amps (low impedance,) there is significant risk of one channel actually affecting another channel when drawing from the same source. For best audio quality, you want to de-couple the power supplies for the four channels, and that means four transformers, or four separate windings on one transformer (and separate filtering caps and separate rectifier bridges.)
If you look at some pictures of K8060, people have used individual transformers for individual amp.
If the determination is to use only one transformer you should be better off getting a transformer with multiple windings that can power each amp separately.
The example below shown three secondary windings by you should be able to get with four.
If you look at these, I have two of them with same transformer connected in series
I think (?) will it affect sound, its double ac24v-28v, 2.1.3 high stereo power bass digital amplifier.