Correct, regarding the voltage. The TPA3116 will be damaged if powered above 26V. The only way to use that part with higher voltages would be to use a DC-DC converter to bring the voltage down to 26V or less.
For instance, the DC-DC converter below can take a voltage between 9V and 53V and output a voltage between 5V and 28V, set by an external resistor.
I7C4W012A050V-003-R - DC-DC converter, 300W, 9V - 53V input, 5V - 28V output
Other boards using the TPA3116 (both still limited to 26V):
MPAB1X100-TPA3116 Mono configuration
MPAB2X50-TPA3116 Stereo configuration
