HEGEL   Testimonials  Back   "Hegel is my reference amplifier", says Jan Erik Kongshaug in Rainbow studio. "HEGEL - the only amplifier good enough for professionals", says Ronnie Le Tekrø. Ronnie Le Tekrø is using the Hegel H4A amplifier for his recording studio called Studio Studio. Ronnie Le Tekrø is a famous musician known from the band TNT.