Problem 1 - Distorted Output

You received this amplifier and the client complained of distortion.  Luckily the client had a favorite song and has recorded it once before and then again as they did not know how to describe the problem other than it doesn't sound good anymore.

Before the trouble audio

After the trouble audio

So you open the local folder containing three things, a bode plot, a schematic with nodes annotated on the schematic, and a note that this is a small amplifier with a variable bandwidth. It appears the previous technician didn't bother to take the copious notes to keep the folder updated with normal voltags and other useful tidbits.

Amplifier Bode Plot

Amplifier Bode Plot

Amplifier schematic

Amplifier Schematic

click on diagram for a larger picture in a new window.

 

Oscilloscope Signals on the listed nodes

Node 5 Node 6 Node 7 Node 8
Node 9 Node 10 Node 11 Node 12
Node 13 Node 14 Node 15  
Node Pos 9V Node Neg 9V Node Vi Node Vo

Good luck on your troubleshooting. If you have any questions or comments, use the contact us form.

 

X

Node 5

Node 5 Oscope

X

Node 6

Node 6 Oscope

X

Node 7

Node 7 Oscope

X

Node 8

Node 8 Oscope

X

Node 9

Node 9 Oscope

X

Node 10

Node 10 Oscope

X

Node 11

Node 11 Oscope

X

Node 12

Node 12 Oscope

X

Node 13

Node 13 Oscope

X

Node 14

Node 14 Oscope

X

Node 15

Node 15 Oscope

X

Node Pos 9V

Node Pos 9V Oscope

X

Node Neg 9V

Node Neg 9V Oscope

X

Node Vi

Node Vi Oscope

X

Node Vo

Node Vo Oscope