Amp/Cab problem. Listen and give your guess as to wtf is wrong here

[Benny H]

http://dl.dropbox.com/u/4924305/fuckedampquestionmark.wav

Listen as I start with the master volume at minimum, and slowly turn it up, to the point where it starts falling apart and completely fucking out. (max I got to here was master is about 70%)

This is a solid state Randall RH100 into 300watt Randall 4x12

I thought it was the cab not handling low tuned chugging (kinda stupid I guess) but on being more thorough in testing it, I'm thinking it's a power section thing?

It happens at lower master volume with higher bass settings, when getting a really full signal such as the woof from chugging. Or full clean chords.

 

[MaxStatic]

Sounds like your amp has diarrhea.

On a serious note, I dunno, I think your guess about the power section being fucked seems about right.

 

[Sweetnothing]

Is the head on top of the cabinet? I had a similar problem with a carlsbro solidstate head, at high volumes, some components on the inside started to get loose solderjoints and made it sound like farting.
If that was the case you could try putting the head somewhere else and see if it helps

 

[Benny H]

I will try that, thanks.

I don't have other amps or cab so I will hopefully be able to take it somewhere to test it more tomorrow.

The thing is.. I was wanting to sell it all!

 

[aortizjr]

You can just try putting the amp on a chair or table and try that. The cab vibrations are probably causing components to vibrate in their joints.

Since the recovery is so fast... try running a cable from the FX send to the FX return and see what that does. Sometimes those jacks go bad the contacts will vibrate.

Beyond that it could be anything. If you have another preamp or amp, you can run a pre-amp into the FX return and try, that will tell you if it is the power amp. Then you can run the pre-amp into another power-amp and that will tell you if it is the pre-amp.

In any case, you will need to be handy with a soldering iron for the repair and make sure you bleed those caps or you could die. For most people, find a tech.

 

[drew_drummer]

Yeah. Seems to be vibrational thing to me; the fact that it gets even worse when you play fuller chords, rather than signal notes. Do you have an FX loop, or anything in the FX loop?

 

[Benny H]

It's not vibrational. It's not the preamp. I've ruled out those.
Actually picked the head up off a seperate table while it was fucking out.. no difference. And the preamp is def. fine.

I just ran a test: pod (amp sim only no cab) -> 330 watt onkyo hi fi power amp -> 300watt randall cab (in mono.. so 115 watt?)
This did not reproduce the same problem. The cab got a bit farty.. but definitely not the same effect.

Another test: randall 100watt head -> "250 watt program" single hi fi speaker (3 way speaker 12" 4" and horn tweeter)
I was able to crank the randall master and it pushed the shit out the 12" ..but it still did not reproduce the same problem.

Fucked if I know..