Is this normal?!

[Only The Best 10+ year member]

I took my amplifier to the electronics lab at my college and hooked it up to a DC power supply with 12.6V. Although when I change the voltage supplied to the amplifier the oscilloscope is showing multiple frequency outputs and it seems to be swaying and tilting as the voltage is varied. Keep in mind the function generator is not even on at this point. I'm curious if this is something normal or if this is the cause of my subs buzzing and popping. The same thing happens when I change the gain the frequency on the scope is moving around erradically.

I am still in the lab now until about 12. So if anyone has any helpful information it would be greatly appreciated. I would be glad to take a phone call if anyone would be so grateful just send me a pm.

Thank yall in advance!



 

---------- Post added at 12:00 PM ---------- Previous post was at 12:00 PM ----------

 

This is on my Rockford Fosgate T1000-1bd

Click to read more...

 

[adulbrich 5,000+ posts]

Harmonic distortion?

 

[Only The Best 10+ year member]

See I was just thinking that It could possibly be the noise coming from the amp considering that its only a 20-50mV rms noise that I am getting but I am trying to hook the function generator up to the RCA's and it is giving me a ***** of a time trying to get a solid connection in order to get an output on the oscope. Initially what I believed to be bad was the rca's. Is there any way to bypass the rcas in order to get this signal to go through the amplifier in order to check this out?

 

[trumpet 5,000+ posts]

I don't repair amplifiers, but I have examined the output waveform with a couple of different oscilloscopes. I always have a sine wave test track or music playing(just for kicks, not for gain setting). If the amplifier has speaker level inputs use that instead of the RCA inputs.

 

[Only The Best 10+ year member]

I don't repair amplifiers, but I have examined the output waveform with a couple of different oscilloscopes. I always have a sine wave test track or music playing(just for kicks, not for gain setting). If the amplifier has speaker level inputs use that instead of the RCA inputs.

I didn't find any. Maybe im blind haha. Let me know if I am.

 

[adulbrich 5,000+ posts]

Use alligator clips and jumper wires to connect directly to the bars between the RCA inputs and board

 

[trumpet 5,000+ posts]

Use alligator clips and jumper wires to connect directly to the bars between the RCA inputs and board

Do this, or cut up an RCA to have bare leads to clip to, or solder speaker wire to RCA barrels to create test leads. There is always a way.

 

[Only The Best 10+ year member]

yeah I wasn't able to get the measurements before I had to go to class but if anyone has any info towards the overall problem, *i.e. subs getting distorted signal at high volume and buzzing and popping* I'd be happy to take any suggestions. And thank you to those for helping!

 

[adulbrich 5,000+ posts]

Distortion at high volume may be from improperly set gain. I don't know about the buzzing/popping though