Additional thought - Check with the amp manufacturer. Some amps have the ability to run on 240 vac built into them, with a simple internal modification. Yours might be one.
Looking at the pictures, is this a hand built amp?...
transformer = yes, but I don't think it will do what your looking for. The secondary (output) is 12 volts AC at 2 amps and it does not say what the primary (input) voltage is.
You can buy a transformer to do what your are...
http://www.pioneerelectronics.com/PUSA/DJ/Headphones/HDJ-2000
That is the maximum recommended power input. Exceed that level and you risk damage to the phones and most likely you will have all ready exceeded a safe...
Also try cupping your hand behind your ear to make your ear "bigger". There was (long ago) a company that marketed leather "ear extensions" on a head band, that extended your ear for improved hearing.
found this...