Experimental measurements of lowhyphen;frequency preamplifiers show that a type LM394 bipolar input stage has less internal input noise than the popular PARhyphen;113 commercial amplifier for source resistances under 10 kOHgr;. A type 2N6483 JFET design shows similar input noise to the PARhyphen;113. The input current noise of the JFET design is insignificant compared with the Nyquist noise of the source resistance.
展开▼
