Blown Yamaha em-100

[guidoilieff]

This is a bad year for me.

I have a yamaha em-100 just for recording because I like the sound of it. A friend of mine connected a cabinet with a speaker and 4 tweeters all connected to the same positive and ground connection (parallel) to the yamaha console. It worked for 30 minutes or less, then it stopped working. The pilot light lights up, the relay makes a click sound after 3 seconds when is turned on and the vu meter moves when there is an input.

What could be the reason of the yamaha not working? Can it be the sum of all the speakers get to 4 ohms or less and thats why the amp broke? You must connect 2 speakers to the amp out? Or maybe he connected it to the Line Out instead of the power amp out?


Thanks and sorry if i didn't made my point clear, my English sucks.


heres what i found inside the cabinet




Yamaha em100


Yamaha em80 (maybe its useful)

[Quackzed]

What could be the reason of the yamaha not working?
amps need a load. with no speakers or too low ohm load (like many parallel speakers) you can cook it.
good news is yamaha makes pretty robust stuff. find the fuse, see if its blown.
dont hook up a lower ohm load than the unit is rated for. if it has left and right speaker connections always use both a left and right speaker of proper ohm and wattage rating. (unless you really know what you're doing via the schematic)
hopefully you just blew a fuse, if not. well, hopefully you just blew a fuse. dont run it without proper speakers connected.
.

[guidoilieff]

What could be the reason of the yamaha not working?
amps need a load. with no speakers or too low ohm load (like many parallel speakers) you can cook it.
good news is yamaha makes pretty robust stuff. find the fuse, see if its blown.
dont hook up a lower ohm load than the unit is rated for. if it has left and right speaker connections always use both a left and right speaker of proper ohm and wattage rating. (unless you really know what you're doing via the schematic)
hopefully you just blew a fuse, if not. well, hopefully you just blew a fuse. dont run it without proper speakers connected.
.

I have replaced all the fuses and its the same. Any idea what specialty I could have cooked?

[guidoilieff]

Is there a way to use just one speaker?.... like connecting a high voltage 8 ohm resistor to a plug or something like that...

[Quackzed]

re: one speaker, it depends on the way the load (speakers) interact with whats driving them, so every type of amp is different.so the short answer is don't do it.

make sure you have speakers connected to both main output channels R and L (not line out)
keep volume  not very loud
try all input channels 1 through 4 or more?
if nothing, try some signal into the reverb return connector..
if anything is blown it might be the ic feeding the l and r speakers. ma(na80045) but it might be something else, that chip looks like it has a resistor closest to the speaker plug. this should help the chip not to die with no speakers connected...

[PRR]

This mixer will NOT be hurt by driving without a load (speaker).

Whatever your problem is, it aint that.

[guidoilieff]

This mixer will NOT be hurt by driving without a load (speaker).

Whatever your problem is, it aint that.

Hi, thanks.

But what about the sum of all those speakers giving less than specified load or just connecting 1 speaker? (I always thought that I could connect 1 speaker without problems).


Thanks again

[guidoilieff]

So, is this ok or I must connect both outputs? (two speakers for the right channel and two for the left)

[Quackzed]

well, if you're chips have a built in load resistance, which it looks like they do, i think you should be ok with just one side connected, left or right. i'd probably try each separate speaker output and see if any of em have signal.

[Quackzed]

btw you STILL don't want to run lower ohms that the outputs are rated for, so for one speaker load, no less than 4 ohms. if hooking up a left and right together no less than 8 ohms ,looking at the back.