Bo Deadly
Well-known member
I'm doing a Pultec HLF3C:
but I'm not using transformers. This will be driven by and buffered by a pair simple op amp circuits. It now occurs to me that this will not work correctly without setting the source and output load impedance.
The question is, what sort of resistor network should I add before and after this to get the correct response? How do I mimic the impedance of the input and output transformers of the original unit using op amps? Just a 600R in series with the input and 600R to ground on the output? Do I want to throw some caps in here somewhere? Then I suppose my op amp buffer needs +6dB makeup gain?
but I'm not using transformers. This will be driven by and buffered by a pair simple op amp circuits. It now occurs to me that this will not work correctly without setting the source and output load impedance.
The question is, what sort of resistor network should I add before and after this to get the correct response? How do I mimic the impedance of the input and output transformers of the original unit using op amps? Just a 600R in series with the input and 600R to ground on the output? Do I want to throw some caps in here somewhere? Then I suppose my op amp buffer needs +6dB makeup gain?