Impedance coupling has not been tried on Pleiades bias amplifiers

Impedance coupling has not been tried yet with low anode voltage Pleiades bias microphone head amplifiers.


Impedance coupling is done with an inductor connected to the anode circuit.


It can be seen used in the final stages of EMI RS61, Telefunken V72, etc microphone preamplifiers.


On a Pleiades V7 it may be used with a deliberate low value of inductance so that high pass premphasis can be created to simulate a magnetic tape recorder recording characteristic.


Then low cut (integration) or de emphasis would round off Instantenious peaks while bringing back frequency response to flat. This technique is also used by Mike Oldfield on crying his guitar sound. See his interviews.


See also:


Analog simulation of analog magnetic tape recording - euroelectron


Further reading on types of class A amplifiers (resistance capacitance coupling, impedance coupling. transformer coupling etc):


Communication Engineering - Everitt - chapter XV
Can be downloaded at www.archive.org or bought on eBay, Amazon etc or read in nice libraries


Radio Engineering - Terman


(In the older days the term radio engineering was used instead of electronic engineering).


Applied Electronics - T. S. Gray - MIT


For a very nice modern book on electronics:


Electronics, a systems aproach - Neil Storey