Prelude part 2 - bus board and line amplifier

Prelude (2) elektor march 1983 Prelude bus board and line amplifier (Part 2) Prelude! Enough of this. Let"s get down to the nitty- gritty: The bus board This board forms the basic for all the mod- ules, switches and other controls. Witness its dimensions: 43.5 x 11.5 cm! These "peculiar" measurements didn"t just happen: the board is tailored to fit standard 19" cabinets. The circuit shown in figure 1 is really little more than a wiring diagram for the various modules. R39 . R42, D5 . . . D7, T13 and T14 are part of the audio traffic-light, described elsewhere; the section around the volume and balance controls will be discussed when we come to the line amplifier. To avoid misunderstandings (these could prove rather frustrating at a later data) the final position of the bus board must be made absolutely clear. The copper track side faces the front panel, and the modules are mounted on the component side — at right- angles to the bus board, of course. Viewed from the front, the EP...