new amp design - lab jc – the website of jc morrison Sep 02, 2009the amp makes 50 watts into 10 Ohms at 3% THD measured with a HP334A. 20 watts is 0.3% THD. no local or global feedback is used to correct the driver stage. more soon ok, so here is a schematic for the amp, the power supply will come later. it may be that this is how i have to publish schemats for now? JC Morrison preamp | Tube | Audiogon JC Morrison preamp for sale. JC Morrison tube preamp with separate regulated solid-state power supply. Tube compliment (4)6dg8. Purist preamp with dual mono volume controls . 1 MM phono input & 3 Line inputs. 1 set of outp..