Beginner PSU question - parallel rating

[NSLogan]

Ok, so i'm reading the tutorial about PSU's posted at the top of the forum (gainclone psu) and am currently looking for a transformer on digikey. The problem is (being a beginner) i'm not quite sure what i'm supposed to be looking for. There are two options on output (parallel and series, i know what those are and what's different between them) and then an option on maximum power (VA). My problem is with the type of output, it's written as: # VAC @ # A. I know that the output then will be in VAC but i'm not sure what the amperage rating means. Is that the maximum load the transformer can support?
Here's basically what i'm trying to accomplish:
-I have two 4 ohm 15 watt speakers i want to run with an lm1876 (one for each channel of stereo input)
-The tutorial on PSU's suggests a 12VAC secondary voltage so i'm matching that on the transformer.
Now: the lm1876 will pull 22W max on each channel so 44W max overall. Does that mean the amperage of the transformer must be high enough to have a maximum power of greater than or equal to 44W?
Basically, would i need a transformer (if i'm in parallel on output) that outputs 12VAC @ 3.67A or more?

[pacificblue]

Originally posted by NSLogan
My problem is with the type of output, it's written as: # VAC @ # A. I know that the output then will be in VAC but i'm not sure what the amperage rating means. Is that the maximum load the transformer can support?

Yes. The nominal voltage is given at that current. Most transformers can support more than the nominal power rating, but the output voltage will drop and as the current draw passes above the nominal current to make up for that, they will run into saturation. That means, what comes out of the secondaries are not clean sine waves anymore. The output is distorted. Those distortions pass through the power supply into the amplifier and will audibly affect its performance. And the transformer will run hot.

Originally posted by NSLogan
Now: the lm1876 will pull 22W max on each channel so 44W max overall. Does that mean the amperage of the transformer must be high enough to have a maximum power of greater than or equal to 44W?
Basically, would i need a transformer (if i'm in parallel on output) that outputs 12VAC @ 3.67A or more?

Absolutely right, except for the parallel part. The LM1876 needs ±10 V or more. You have the choice to use a single supply, meaning those 12 V secondaries would have to be connected in series or to use a split power supply, meaning each secondary feeds one half of the split supply. Parallel connection would leave you with 12 VAC -> ~16VDC at idle and ~14VDC loaded and the LM1876's undervoltage protection would probably not let you listen to any music.