It depends which generation of Carver amp it is. There have been reviews and stories that some Carver amps when tested didn't meet the specs that he claimed, but some of his amps actually measured higher power than the spec sheet. These measurements are for peak power, so they would not be noticeable in everyday listening.
And with amps from the Carver years, their high power also included high levels of distortion. This measurement may not have been rated truthfully by the designer.
The TFM amps were very popular and had good sound for their day.
Do you know which amp series your son has?