Apr 24, 2003 #1 A ahgu Full Member level 3 Joined Jun 19, 2001 Messages 172 Helped 1 Reputation 2 Reaction score 1 Trophy points 1,298 Activity points 1,552 I want to use either bjt or cmos to act as small preamp for an electret mic. in the ball park of gain of 10 probably use in common emitter configuration. Which one has lower noise? and which part should I use for lower noise? part number? thanks Ahgu
I want to use either bjt or cmos to act as small preamp for an electret mic. in the ball park of gain of 10 probably use in common emitter configuration. Which one has lower noise? and which part should I use for lower noise? part number? thanks Ahgu
Apr 25, 2003 #2 flatulent Advanced Member level 6 Joined Jul 19, 2002 Messages 4,624 Helped 489 Reputation 980 Reaction score 151 Trophy points 1,343 Location Middle Earth Activity points 46,689 Try JFET Try a JFET. They have lower noise in the audio region than either MOS or BJT. The U301 or J301 will work well.
Try JFET Try a JFET. They have lower noise in the audio region than either MOS or BJT. The U301 or J301 will work well.
Apr 25, 2003 #3 A arturt134 Full Member level 2 Joined Dec 31, 1999 Messages 125 Helped 8 Reputation 16 Reaction score 8 Trophy points 1,298 Location Poland Activity points 1,006 Please tell me who manufacture this amplifiers? Thanks in advance.
Apr 25, 2003 #4 flatulent Advanced Member level 6 Joined Jul 19, 2002 Messages 4,624 Helped 489 Reputation 980 Reaction score 151 Trophy points 1,343 Location Middle Earth Activity points 46,689 discrete transistors These are discrete transistors. Many companies make them.
Apr 26, 2003 #5 A ahgu Full Member level 3 Joined Jun 19, 2001 Messages 172 Helped 1 Reputation 2 Reaction score 1 Trophy points 1,298 Activity points 1,552 differential preamp with 2 jfets? how can I make a diff jfet amplifier? want to min the noise. using 2 jfets. thanks ahgu
differential preamp with 2 jfets? how can I make a diff jfet amplifier? want to min the noise. using 2 jfets. thanks ahgu
Apr 26, 2003 #6 A ahgu Full Member level 3 Joined Jun 19, 2001 Messages 172 Helped 1 Reputation 2 Reaction score 1 Trophy points 1,298 Activity points 1,552 diff jfet amp with device matching , I wonder if it is actually better to use 2jfets, WRT just one jfet.
diff jfet amp with device matching , I wonder if it is actually better to use 2jfets, WRT just one jfet.
Apr 26, 2003 #7 flatulent Advanced Member level 6 Joined Jul 19, 2002 Messages 4,624 Helped 489 Reputation 980 Reaction score 151 Trophy points 1,343 Location Middle Earth Activity points 46,689 doubled noise You will get double the noise. The topology is the same as BJT or MOS amplifiers.
Apr 26, 2003 #8 Borber Advanced Member level 5 Joined Dec 31, 1999 Messages 1,600 Helped 235 Reputation 472 Reaction score 111 Trophy points 1,343 Location on third flor Activity points 11,863 bjt Transistors BC550 NPN F=0.6dB at Ic=200uA Vce=5V f=15Hz-15kHz BC560 PNP F=1dB can be used.