Is this amp bad?

[bradfordpoole 10+ year member]

I just bought a used Memphis Power Reference amp. The amp is 100.2. Im trying to run my front door speakers off the amp. The Front door speakers are Earthquake VTEK 6.5 comps. When the amp powers on without the speakers hooked up to it, it runs fine. But when the speaker wire is connected the amps power light will die down and then turn back on. The music will play for a second then the amp shuts off and then powers back up and so on.

Are the channels in this thing bad?

Click to read more...

 

[whitedragon551 5,000+ posts]

Have a DMM? Check the readings on the speakers. Check the outputs on the speaker channels to see if you can get a reading. If it shuts off with the DMM leads what is it doing (to high of a voltage, to low, etc). Check your grounds, power, fuses, and make sure everything is wired correctly and all screws, bolts, nuts, what ever are tight. Also make sure you wired the speakers correctly to the amp.

 

[mike49504 10+ year member]

Like stated set your multi meter to ohms and check the speakers to make sure the coils are not shorted. Then set your multimeter to dc voltage place black meter probe on the negative speaker terminal of the amp and the red probe on the positive speaker terminal do this for all channels do you get and voltage readings if so post the results.

 

[bradfordpoole 10+ year member]

Everything checks out fine? Its 4ohm

 

[VWBobby 10+ year member]

I think Mike meant set your meter on AC.... If you set it on DC and try to measure output on the speaker terminals the voltage will jump so much you can't get a good reading.. Music puts out an AC (push-pull) signal when measured at the power side of an amp.

You can also try driving some small speakers. If it can drive the small speaker but not drive a regular 6.5, then you know the amp is shorting out or the drivers are being overloaded for some reason and needs repair. Just in case, I would test your speakers with another amp also.