Magnavox 8300/8600 Single-Ended Triode (SET) 12BH7 Conversion

Magnavox 8300/8600 Single-Ended Triode (SET) 12BH7 Conversion This page contains some resources for converting a Magnavox 8300 or 8600 series amplifier to run 12BH7 dual triodes as output tubes. It complements my YouTube video (above). The Magnavox 8300 and 8600 run 6BQ4/EL84 outputs and have a single 4 ohm secondary winding on their output transformers. Because the majority of high-sensitivity speakers are 8 ohms, this poses an issue for many users. Audiokarma tube guru dcgillespie recommends this problem be solved by replacing the original transformers with new 8 ohm ones. However, it is my philosophical belief that output transformers are […]

Heathkit A-8A

Heathkit A-8A The Heathkit A-8A is a rare Heathkit integrated amplifier capable of around 15 watts per channel. It has three inputs — crystal phono (which can be used with line-level sources), mic, and magnetic phono. The tube complement is two 6SJ7 pentodes, a 6SN7 double triode, two 6L6 beam tetrodes, and a 5U4 full-wave rectifier. I bought this amplifier from a Craigslist seller who intended to restore it but never found the time. This example has a Chicago PCC105 power transformer and a Peerless S516A output transformer, but other A-8As may utilize different iron; the schematic and parts list […]