The Heath W-5M is a mono amplifier which is an implementation of the classic Williamson design. It uses a pair of 12AU7's in the driver section and a pair of KT-66 output tubes. The Power supply uses a 5R4 rectifier tube. This amplifier is a very good sounding unit. This is due to a number of factors. First, the power supply is very robust, with a large inductor and lots of capacitance. Second, the Williamson design is a solid performing topology. Third, the output transformer, made by peerless, is phenomenal. This amplifier like the others listed on this page, is a unique and very enjoyable unit which should provide years of audio enjoyment. As such, this amplifier deserves to be preserved. I designed a capacitor board which replaces the can capacitors and the extra axial electrolytic capacitors in the power supply.