Join Date: Mar 2003
Location: Willmar, Minnesota
constant current source question
I have a question for everyone. I'm pretty much a newbie to the world of do it yourself audio and so I have been spending quite a bit of time looking at all the different power amplifier schematics available on the web. Ie. “The leach Amp” etc. and i've noticed most of these power amplifiers have a discrete differential amplifier on the front end which takes the input signal and subtracts the feedback signal. I can understand why you would want to do that but what I don't understand about the differential amplifiers is why they have a constant current source feeding them? I've done some simulation of a differential amplifier without a constant current source and it works perfectly fine. What does a constant current source do and how does it benefit the differential amplifier circuit?