I dont know what the admins are doing, moving half of my post around. seriously?Why do teachers post horrible old circuits like that??
Your circuit is missing a solder joint at the collector of Q1, R13, R14, D1 and D2.
It is also missing very important negative feedback.
It is also missing a very important supply voltage.
Why is the total gain of your three opamps 20 x 16 x 40= 12,800 times?? The output will be nothing but hisssssss.
We are both wrong. The gain is 20 x 1.6 x 40= 1280 times. So a 15mV microphone input will make an output of 19.2V.Gain is 20, 1.5 and 40
Yes I doWe are both wrong. The gain is 20 x 1.6 x 40= 1280 times. So a 15mV microphone input will make an output of 19.2V.
Do you have two threads for this circuit?
@Remix23 @Audioguru againYes I do
The new schematic you posted uses an appropriate low-noise, high-speed opamp and has overall negative feedback. Much more likely to work well.Yes, my math is also bad. Then the total gain is 20 x 2.5 x 40= 2000 times, or +66dB.
Here is a similar power amplifier producing 18W into 8 ohms:
There needs to be a supply behind it, tried to ask how i go about it, no response.What is the point of having Q1?
by Jake Hertz
by Aaron Carman
by Jake Hertz