There are no resistors in the transformer circuit. If you use the wrong transformer then the voltage will be wrong.
A 22V-0V-22V transformer will produce +29V and -29V at its rated current and will produce about +31.5V and -31.5V with low current.
The max allowed supply voltage for the TDA7295 is 80V.
A 22V-0V-22V/3A transformer is rated at 44V x 3A= 132VA. when the amplifier has a 50W output then it heats with about 40W so its total power from the transformer is 90VA and the transformer will not over-heat. A 2.5A transformer will also be fine.
you don't listen to music at full blast all the time so a 2A transformer will be fine.