Harman Kardon Citation V Performance
- Thread starter TriodeLuvr
- Start date
Not only for the PT. Because it slightly lowers the input AC voltage (which runs higher these days than when the amplifier was released). You will find them in many tube power amplifiers with SS rectification (Mc40, Mc75, Mc225, Mc240, Mc275, etc). Also gets rid of the turn on "thunk" when power is applied. Perhaps someone will chime in with a more technical and less practical explanation than mine.
Inrush limiters are not only for tube-based equipment. Quite the contrary, solid state equipment needs it more, especially devices with switching power supplies or high loads (capacitance/inductive/in-rush) at turn-on.
Ironically, there are two versions of the factory schematic in that thread, and one of them has a printing error. In the excerpt below, note that the 1K resistors in the bias network have been misprinted. They should be 10K. The same error appears in both channels.
The purpose of the thermistor provided in the Jim McShane kit is to allow using a smaller fuse for better amplifier protection (the new fuse is also provided in the kit). This is required because the very large amount of added capacitance in his kit creates such a high inrush current.
Jack