Input impedance

[Synchrodyne]

Something else I recall reading about in one of the Australian magazines in the early-to-mid-1970s was a so-called “charge-coupled amplifier” used as an input stage for a ceramic cartridge.  My vague recollection is that this lacked a loading resistor for the cartridge, and that it was of the virtual earth type with some kind of capacitive feedback network.  I think it was a constructional project – something like “Build a Charge-Coupled Amplifier”, but I guess the chances of tracing it now are asymptotic to zero.  Perhaps though the ITT-KB amplifier at interest was of a similar nature.


Cheers,

Steve