Transformer Question

[RookieRecurve]

Hi all, I got my kit last week, and was looking at options for powering the amp, and discovered I have a power transformer from an old Dell powered-speaker set.  It outputs 17v AC and 2.5A.  I have a full-bridge DIY rectifier kit on its way to convert it to DC.  I am not sure what the final DC voltage will be, but I am hoping for 16 VDC.  I cut open some shrink wrap on the power supply, and found a 0.1uf 275VAC capacitor in there.  Any ideas what this is for?  It appears to be wired in parallel?  Any thoughts on my proposed power supply?  I figure it's free, and it's great for learning more.

[Loudthud]

After rectification and a filter cap, the output will be close to 24VDC. To get 16VDC, you will need some kind of Voltage regulator.

[RookieRecurve]

I was under the impression that a full-bridge rectifier would drop the voltage?  I guess too much voltage is better than too little as it should be easier to drop it than to increase it.

[J M Fahey]

A rectifier, including a bridge, will charge supply capacitor to 1.41X AC voltage, so about 24VDC as stayed above.
You can* down regulate it to 16V or whatever this mini amp needs.
Simplest is using a 7815 and a diode or two to rise voltage reference, or use an LM317 which costs cents more and is fully adjustable.
You will need some heatsinking for the regulator , at least of aluminum sheet or rail
 

[RookieRecurve]

Thanks for the help with this.  I bought a DIY full-bridge rectifier kit, and powered up the transformer.  My output voltage is 25.3 VDC, so I will definitely need to step that down.  I order up an inexpensive buck converter that is adjustable down to 3.2v, so I will easily be able to step this voltage down to the 16vdc that I am going to need.