whats up with my amp? (vid inc)

harry182 · #1 07-15-2010, 11:42 AM

As above,....

Vid will say better than i can describe,...

http://www.youtube.com/watch?v=pvKpsR-kS9k

its a marshall bass state b150

when i play it, itll be normal, then itll just cut, make a kind of click noise as if you were to plug the lead in to a bass with the amp on, then plays distorted.

Itll then click out and play normal?

What you hear in the vid is how it comes out, its not because of it being so close to the amp

Any idea of what it could be?

Might be worth noting that i have been using active basses through the passive input as the active in put didnt work, but this has happened before i got the two active basses (active input isnt currently working)

Please Help

Thank you

Harry

BassmanPaul · #2 07-15-2010, 11:48 AM

Sounds like it's tech time. Intermittents are the worst problems to diagnose. It's very doubtful that we can do so across the internet

Paul

Govier966 · #3 07-15-2010, 11:52 AM

my amp did the same thing, warped voice coil i believe. i think its time for you to get a new cab.

::::BASSIST:::: · #4 07-15-2010, 04:27 PM

I dont know whats wrong with your amp, but my 5 year old son really enjoyed your drumming video. He says your silly. He also says 'the darkest hour'.... not sure what that is supposed to mean.

http://www.youtube.com/watch?v=wUuTr...eature=channel

harry182 · #5 07-15-2010, 05:49 PM

I would love to take it to a tech, but sadly, theres no shops around here id trust to do anything more than sell me strings

and :::Bassist::: ye thats a funny vid, on a car forum were thers a kind of performance thread, i did a ruff video but thought that a vid of me not doing so well was better,

i have mad head rushes and find it more entertaining to shout at them then hit them.

this is my proper you tube channel.....

http://www.youtube.com/user/HarryHopkinson

craig.p · #6 07-15-2010, 06:10 PM

Let's assume it takes five minutes while you're playing to go from good to distorted. Will it take the same five minutes if you're NOT playing? In other words, power the amp up from cold, play only one or two notes to make sure the sound's ok, then wait the five minutes but let the amp stay silent during that time, then go back and play again and see if the sound's become distorted.

Replace "five minutes" above with whatever time-to-fuzz-sound value you're seeing when this occurs.

harry182 · #7 07-16-2010, 06:06 AM

ye will give that a go tonight

What are you thinking it could be?

craig.p · #8 07-16-2010, 07:48 AM

> What are you thinking it could be?

Not sure yet, Harry. All we know at this point is that this is probably a heat-related issue since it doesn't surface until the amp's been played through for a while. That's not a lot to go on. What we need to find out now is WHAT inside the amp is buzzing when it gets warm.

What we're trying to do is use a) amp-section heating and b) heat migration as troubleshooting tools.

Possibilities:

* Cracked circuit-board etch due to physical shock or bass vibrations.

* Cold solder joint (manufacturing defect) or solder joint that's come undone due to physical shock or bass vibrations.

* Blown speaker, as Govier suggested.

* Loose connector (cable, pin, spade lug, etc.) somewhere inside the amp. Heat causes parts to change dimensions and can make mating parts fit better or worse.

* Component that's become heat-sensitive so its value changes once it's warmed up.

Are you prepared to remove the amp from the cab? Removing the amp from the cab (and extending the speaker wire, possibly several feet, so you can run the amp physically separate from the speaker) will be necessary to chase down a heat-related problem that is NOT the speaker itself. I'm assuming the speaker box will remain sealed with the amp removed. If you're not comfortable doing this, then do what Paul said.