I'm talking about low level circuits here, such as head amplifiers in a condenser mic... just studying all those tons of schematics from neumann, schoeps, akg, gefell etc. There are issues of basically the same mic but with a different biasing method in later versions. to be more precise, most very early circuits use a fixed bias for the grid, while later ones use self-biasing (meaning, grid resistor to ground instead of to a different point, plus cathode resistor with bypass cap to groubd).
i wonder why they turned to self biasing later on? improving of specs regarding noise? reducing unit-to-unit variations of tubes (since self-bias is the method less affected by it)?
also, do different biasing methods affect the dynamic behaviour of a circuit, i.e. the sound?
thanks for any thoughts, cheers,
volker
i wonder why they turned to self biasing later on? improving of specs regarding noise? reducing unit-to-unit variations of tubes (since self-bias is the method less affected by it)?
also, do different biasing methods affect the dynamic behaviour of a circuit, i.e. the sound?
thanks for any thoughts, cheers,
volker