The transformer looks bigger in the pictures than it is in real life. I would say it's about 2" in diameter and maybe 1.5" high, using an eyeball measure.
The power supply board it is attached to may be about 2" wide by about 4-5" long. The audio output board is bigger, maybe 3" wide by 7" long, again using an eyeball measure.
Please let me know if you're interested in trying it out.
Thanks,
Bob