Question for the stereo gurus
 

My sub amp a JL 500/1 stopped working, I pulled the fuse and it worked again for the rest of the day. When it happened again I tried the fuse again and it didn't work. I then noticed the sub barely moving so it was working partially. Can a amp partially go out? Thanks in advance.

Sure, an amplifier can go partially out. For example, there are multiple positive and multiple negative output transistors and a failing transistor can be either in a state of failing or completely out, whether shorted or open.
Unless there is water damage the manufacturer will usually repair the amplifier at a fixed rate. If you have a Slash 500/1 you couldn't adequately replace that amplifier for anywhere close to twice the repair price.

David
Earmark Marine

Thanks for the reply, I hooked up another sub and there wasn't any change. I forgot to mention that it all goes through a ws420 if that makes a difference. And yes it is a slash series with no water damage.

Just to eliminate the EQ from the equation, circumvent the EQ by temporarily bypassing it and coming straight from the source unit. Also, pull another EQ output temporaraily to the sub amplifier. All outputs are fullrange and will drive the sub amplifier for testing purposes.

David
Earmark Marine

Do me a favor and check your RCA connections at the amp and back of EQ. They can be barely plugged in an partially passing signal... Unplug them and re plug them in making sure they are all the way seated... Just a thought besides what was stated...

Sam - Before replacing or repairing, I'd do some more trouble shooting. an easy solution here would be to bypass the 420 and the source deck, by taking an iPod cable and plug directly into the amplifier and play directly into it. MAKE SURE YOUR IPOD VOLUME IS TURNED DOWN A BIT. This in effect, eliminates all potential problem area's up stream (meaning deck and 420). If you still have a problem, then yes, its the amplifier.

A word of caution about repairing amplifiers that have blown outputs or blown power supplies. Make sure you talk to the repair tech and find out if you have another problem with the same amp its covered and for how long. Especially if its a flat fee. Sometimes in current production models a mfg will just pull the board and put a new one in. Others repair the board. I suspect in this situation your looking at a board repair.

Good luck.

-Brian

Great suggestions, thanks. I will try all and post back.

I pulled the sub amp out of my truck and hooked up the boat amp. Very little output from the boat amp- JL 500/1. The truck amp is a bridged 300/2 and hit way harder. I guess I got my answer.

Thats a good test too. Yes, I think you got your answer.... indeed.