Crisis, Pleas help!!!!

[Dr.Mavashi]

My AOR went dead, I was playing at 16 ohms, then turned it off, changed the impedence to 4 ohms took about 10 minutes off, truned the thing back on ... and nothing ... nothing in the speakers, all tubes light up, but nothing, when you you strum chords and listen to closely you could hear this whee-ou, whee-ou whee-ou like a little mosquito somewhere deep inside the amp, I dont know, this little noise could be coming from the cab, but its in the back of the half stack, this is sucks ... I hope its nothing major ....

 

[Dr.Mavashi]

Re: Crisis, Pleas help!!!!

Ok, I actually barely if I put my head really close to the pream tubes can hear the crunch and the notes I am playing but its complete silence in the speakers not even hum could be heard ....

 

[Dr.Mavashi]

Re: Crisis, Pleas help!!!!

Somebody talk to me, I am really freaked out I've some how killed my transformer ...

 

[WhoFan]

Re: Crisis, Pleas help!!!!

this sounds strange..... what was the ohmage of the speaker you where sending the amp thru?

 

[Dr.Mavashi]

Re: Crisis, Pleas help!!!!

4 to 4 ohms ...

 

[WhoFan]

Re: Crisis, Pleas help!!!!

4 to 4 ohms ...

and before you had 16 ohms running into 4ohms?

 

[Dr.Mavashi]

Re: Crisis, Pleas help!!!!

now before was 16 into 16, then I switched, I am sure I turned off the amp before switched to 4-to-4, even if i did it with a power on, which I am pretty sure I turned amp off before, but anyways even if I did, it was on stanby, and when I switched stand by off, there was nothing. When I turn it off beside hearing a bit buzz and very distant actuall guitar inside the head of the amp, if listen I could heat the quite hum of the transformer. Man I hope I did not kill it ... please let be just old tubes ...

 

[WhoFan]

Re: Crisis, Pleas help!!!!

i'm am no expert on amps and ohmage.... so i may not be any help to you... but i just wanted to understand the issues and the events leading up to the amp dying out....

if i understand it you are using the amp thru a Marshall 4x12 with a Stereo Mono switch on the back and those ohmage selectors on Marshalls have confused me for ages...

does the amp not work when you switch everything back to 16 ohms..?

 

[Dr.Mavashi]

Re: Crisis, Pleas help!!!!

DUDE YOU ROCK, 16 ohms works, I dont understand why 4 ohms does not at all .....

 

[ES350]

Re: Crisis, Pleas help!!!!

right---switch everything back to conditions before the failure and check and doublecheck everything---eliminate any errors (cab wiring, cable failures, etc). Meter the load for continuity and check the ohm settings on the cab and the amp. If it still doesn't function, sub a set of known good tubes and see what happens...it's not blowing fuses and it powers up (good). No output could be a lot of things from a cold solder joint someplace to a blown OT...take it to a tech.

 

[Dr.Mavashi]

Re: Crisis, Pleas help!!!!

So you are saying I could have blown my OT anyway allthough the 16 to 16 ohms work?

 

[Dr.Mavashi]

Re: Crisis, Pleas help!!!!

Ok, this is realy weird, 4 ohms to 4 ohms setting completely dead! 16 to 16 works fine it seems, what can it be ?

 

[ParameterMan]

Re: Crisis, Pleas help!!!!

Could it be the switch in your cabinet?

 

[muttonchopsrule]

Re: Crisis, Pleas help!!!!

check the wiring in the amp to make sure all the wiring for the speaker output jacks and impedence selector (if that amp has one) is intact.

 

[Dr.Mavashi]

Re: Crisis, Pleas help!!!!

Laney AOR impedence selector is 4,8,16 ohms, the one you need a screwdriver to turn, with a push before turn. The it looks you have to extract the chasis fromt the casing of an amp to get to it, I dont think I can look at the insides of that switch from the outside, opened up the cabs jack panel, all four wires are fine .... drive me nuts, i am jaming with with friends this sunday, and not having my perfect tone by playing through the 16 ohms just dives nuts, plust now its gonna be more than just 50 bucks for the biasing job, that is scheduled for next week. Well, at least I didnt fry the transformer right ?

 

[lastwinj]

Re: Crisis, Pleas help!!!!

leave it at 16. i suspect the amp is not getting a load from the speaker cab. to check, leave amp at 16, and try the 4 ohm setting on the cabinet. use lo volume. does it work? if not, i suspect the cabinet switch. then try 4 ohm amp, 16 ohm cabinet. does it work? if not, impedance selector switch.

 

[Dr.Mavashi]

Re: Crisis, Pleas help!!!!

Ok to check for which switch broken:
4 ohms on an amp and 16 ohm on a cab, to check the impedence switch?
16 ohms on an amp 4 ohms on a cab to check the cabinet jack.
Now isnt one of these miss-matches can fry the OT??? Thank you dudes.

 

[Dr.Mavashi]

Re: Crisis, Pleas help!!!!

Bump.

 

[muttonchopsrule]

Re: Crisis, Pleas help!!!!

Now isnt one of these miss-matches can fry the OT??? Thank you dudes.

if you only do it for long enough to see if there's sound coming out of the speakers, the amp should be fine. if you mismatch impedence when the amp is on for an extended period of time, then that's asking for trouble. but having it mismatched for 10 seconds should be no big deal.

 

[Dr.Mavashi]

Re: Crisis, Pleas help!!!!

if you only do it for long enough to see if there's sound coming out of the speakers, the amp should be fine. if you mismatch impedence when the amp is on for an extended period of time, then that's asking for trouble. but having it mismatched for 10 seconds should be no big deal.

For some reason I am just to try this now ..... its going to a tech on thursday, but I will jam with it tomorrow set to 16 ohms, and I am stressed out about it too .... anybody else can add something??? thanks ....