Amp problems

Jap GT300 · November 14, 2003, 14:28

Okay I have installed an amp as per the instructions, but I am getting serious problems.

It is a 600w 4 channel. I am using 2 channels for some 6x9 and have bridged the final 2 channels for the sub.

I have so far only connected the 6x9. When I turned everything on the right hand speaker was performing normally but the left was pushed all the way out. I then turned the terminals around but it now pushed all the way in. I swapped the cable with the other speaker and the same thing happened!

Thinking that i had got the polaritys wrong somewhere I checked everything and it all seemed to be okay. I then realised that it said in the manual that the AMP should go to the negative battery terminal. As I had grounded the amp I changed it but it still doesn't seem to have cured my problem.

What have I done wrong?

Slacey · November 14, 2003, 14:31

I'm not quite fully trained yet Adam, I think I'd better wait for Buster to answer this one s:oops: :oops: s:oops:

markiii · November 14, 2003, 15:07

when you say the same thing happened when you swopped speakers over.

Are you saying that teh same thing happened to teh original speaker or the new one?

Sounds like you have some DC in there somewhere.

SteveJ · November 14, 2003, 15:24

Quote from: "markiii"when you say the same thing happened when you swopped speakers over.

Are you saying that teh same thing happened to teh original speaker or the new one?

Sounds like you have some DC in there somewhere.

Mark's right - you have a large DC component on the output.

2 scenarios depending on the amp :-

1) The DC blocking cap on the output has gone short-circuit

2) One of the MOSFET's has gone short circuit

Either way, the AMP is toast and needs to be repaired/replaced and there is a good chance the speaker is going to be damaged too - it was never designed to withstand a sustained DC input, as it causes the coil to overheat EXTREMELY quickly.

Jap GT300 · November 14, 2003, 16:55

Your right about the speaker! I have one melted voice coil.

Is the extra DC through a manufacturing fault or have I done somehing wrong with the settings?

Thanks AdaM

SteveJ · November 14, 2003, 17:00

Quote from: "Jap GT300"Your right about the speaker! I have one melted voice coil.

Is the extra DC through a manufacturing fault or have I done somehing wrong with the settings?

Thanks AdaM

The amp should NEVER be able to put DC on it's output so it's a manufacturing defect - if it was a new unit, you should probably get them to pay for the speaker too.

Anonymous · November 17, 2003, 19:52

Sounds like the old favorate of being Mono stable instread of stero!

This means that when shifting teh fazses you are not as it's in mono rahter than stero!

Also cheak that you havent got it switced teh wrong way on the 3 channel! i.e it's not just channel 1 and 2 for 6*9's and 3-4 for teh sub it can be different !

Jap GT300 · November 18, 2003, 07:14

You may be on to something there Buster. As I had three speakers I put it onto 3 channel, but because I have bridged for the sub do you think it should be on 4 channel?

Shouldn't the amp have some sort of safe mode to protect against this?

Thanks Adam

SteveJ · November 18, 2003, 08:24

Quote from: "Jap GT300"You may be on to something there Buster. As I had three speakers I put it onto 3 channel, but because I have bridged for the sub do you think it should be on 4 channel?

Shouldn't the amp have some sort of safe mode to protect against this?

Thanks Adam

Regardless of the mode the amp is in, IT SHOULD NOT HAVE ANY DC COMPONENET ON THE OUTPUT - THERE SHOULD BE BLOCKING CAPS TO PREVENT IT

Any DC on the ouput terminals indicates either a design fault (and if a particular configuration allows this there should be a bloody BIG sticker warning you), or that a fault has developed on this particular unit. Either way get it swapped if you can, and then read the manual fully before trying again.

Anonymous · November 18, 2003, 11:37

Quote from: "Jap GT300"You may be on to something there Buster. As I had three speakers I put it onto 3 channel, but because I have bridged for the sub do you think it should be on 4 channel?

Shouldn't the amp have some sort of safe mode to protect against this?

Thanks Adam

Normally if you put it into 3 channel you norally bridge channels 3 and 4 so use the - of 3 and + of 4, this will power the sub and then the channel 2 and 1 are left for the 6*9's

But not all amps are the same so look inthe maunal first or tell us what the modle number and make is and im sure i can find out.

But the map wont have an protection against wireing it up wrong and giving it the wrong ohm's on load s:? :? s:?