I'm planning to build a TDA2030 amp with a single power supply based on the datasheet schematic driving an 8 ohm speaker.  I was initially going to power it with a split power supply from the GGG schematic, but I came upon an old printer power supply that I want to use if will work ok. I have a few questions about the feasibility of using that PS. This is just an amp to use while breadboarding, so I don't need to extract all the performance the chip is capable of.  I just need enough clean headroom to prototype stuff.

The 2030 is rated for +/-18V or +36V, 3.5A peak output current.

http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATASHEET/CD00000128.pdf

http://www.generalguitargadgets.com/pdf/ggg_bipolar_ps.pdf


1)  The printer PS is rated at 13.5V/1A, but measures about 17V without a
load.  Why is it measuring that high?  Will the output voltage drop when the
PS has a load on it?


2)  The 2030 datasheet says the wattage output is about 4W with 17V, but is 1A
enough current?   


3)  The single supply schematic has a 2000uf cap on the output to the speaker,
but there is no cap on the split supply schematic.  What does this cap do?


4)  What about building a circuit to give me a split supply from the printer
PS so I can build the amp with a split supply.  That will give me the option
to swap out the PS for another PS like the GGG +/-PS if I'm not getting enough
power out of it.  Good idea?  Bad idea?  Any schematics you could point me to
for this?


5) Any suggestions for what I should be looking for in a transformer if I do
build the GGG PS for +/-18V?