My amp is broke?

hello

I resently bought the new Marshall AFD 100 top and it's amazing! But i think something might be wrong.. i don't know if it's the amp or maybe the cabinet or even my guitars that somethings wrong with.
It like when i play on low volumes it tends to get this behavior... At some point it lowers it's output so you nearly can't hear it. and then it gets back up again after some 5 to 10 seconds and then sometimes it repeats. I don't know whats wrong. It sometimes does it, and sometimes don't. I don't think it does it when i turn it pretty much up. But i can't practice that loud

what could be wrong?! :confused:

Is that a tube or solid state amp?

It might be a bad cable somewhere. Make sure your cables are good. Both your instrument and your speaker cables.

If it's not that, perhaps it could be that your volume potentiometer is dirty? I know you said it's new, but...if there is a way to get to it and spray some compressed air or contact cleaner on it, maybe that might do the trick?

(I'm sure I don't have to say this, but just in case, PLEASE do not use an instrument cable as a speaker cable!)

It's a tube amp, and a wild one too. And yeah, i figured it might be something with the cables, which would be good if it is. I will try to swap them out but i have a question.

What do you mean by not using guitarcables for speakercables? I just use the one that followed with the amp which is just a very small jack cable. Is that bad?

Thank you

Guitar cables are sheilded. The low voltage signal is susceptible to interference, so sheilding is required.

Speaker cables are not sheilded. They carry a higher voltage which is not so susceptible to interference. Thus no sheilding. But the main reason is a sheilded cable can overheat, short, and fry your amp, catch on fire, all kinds of fun stuff.

That said, you can use a guitar cable for a quick test at bedroom levels, but I would not leave it like that.

Hard to say for sure why your levels are dropping. Could be anything from a bad solder joint to a bad power supply. Try changing out one peice of equipment at a time. First thing I'd do is plug in a different guitar and see what happens.

So i should immidiatly get a new cable for the cab? im not sure i get what you say. I play the top as a mentioned out of a german Framus cabinet. When you say speakers do you mean cabinet?

On the back of both amp and cabinet theres an input for jack to jack cables. Does it matter which i use? if not, please give a link for the one i need

Yes, sorry. Speakers/cab: same thing.

So, to run from your top (ie: head) to your speakers (ie: cab) you can use this:

http://store.daddario.com/category/146498/Classic_Series

If you've been using a guitar cable, that could be a good place to start. The wires could be heating up just a bit so they have deteriorated over time.

That said, I was in a shop where a guy was fixing an amp that was having volume drops (but it would drop and stay dropped). The problem there was in the amp's power supply. :(

I would borrow a guitar and cables (if you need to) just to isolate the amp from (or as being) the problem. If you do that and have the problem, it is likely your amp.

If not, pull any pedals out of your chain. Change the parts that are left one at a time (guitar through existing cables, if that's not the prob, put the old guitar back, try changing the cable. Do one thing at a time until you isolate the problem. It's another good reason to have a back up of everything you use.

Originally Posted by: caponi14
What do you mean by not using guitarcables for speakercables? I just use the one that followed with the amp which is just a very small jack cable. Is that bad?
Thank you

The cable that came from your store with the amp (in the box) is fine (although poor quality).

If it's the power supply im gonna freak out in anger. I don't have any chance to send back the amp to where i got it from with the money i got now. Neither do i have money for a new power supply if thats even possible to get?... Im gonna rage on somebody if it's the power supply or any other thing from inside the amp (i have zero knowledge of whats inside that thing). I just bought the damn thing. And i have paperproof that it's been tested by the people at Marshall.... I will try what you say thanks.... ****!

It could be a bad tube, its not uncommon for a tube to go bad early in its life especially after the amp has been transported from the factory by the postal service or a courier.

Check the cables first.

If you don't know anything about the amp then get some help because opening it up is dangerous, there is very high voltage in there that will kill you.

Hello and thank you, i don't know anything about whats inside those amps, it's strange, the behavior seems to go away when i turn it up a bit. But also i think it's the cables, cause if i roll the cables all the way out so they don't tangle up it don't seem to do it.

Hey caponi14,
It seems like you need to clean your amp, to put it another way, you need to clean the pots on the amp. Make notes of your settings, and remove the knobs. Use compressed air to clean them, but don't get the cheap stuff, get something with a name. You also want to make sure you can use it for audio, and that it won't harm any other parts. After spraying them, give them a few good twists, spray them again, and give them a few more twists. This should remove the dust, or whatever is causing the problem.

This would be the first thing I would try anyway, and you still want to check all of your cables too.

Let me know if this helps, and I hope it fixes it.

Hi. I had the same problem not too long ago. It turned out to be an effects pedal [battery was dead]. But it could also be a loose or bad tube. Most likely preamp. Or wrong or bad cable etc. Good luck!

The most important thing to remember when troubleshooting stuff like this, is to always check the easier stuff first. Doing this can give you several benefits...

1) It can reduce the complexity of your troubleshooting.
2) It can reduce the time it takes to troubleshoot the problem.
3) It can save you $$$ when solving the issue.

So in this scenario, CHECK THE CABLE FIRST. All the suggestions here are good and could potentially be the cause of the problem, but CHECK THE CABLE(s) FIRST!

You'll thank me later. :)