Super Cobra Audio runs very hot?

[mgkastra]

After having a Super Cobra on for a couple of minutes, I noticed the audio heat sink/shield was extremely hot. So hot that I couldn't touch it for longer than a second.

I know that the audio goes out on these pretty often. Is it normal for it to run that hot?

 

[mattosborn]

Make sure the speaker is 8 Ohm and not 4 Ohm.

 

[mgkastra]

Make sure the speaker is 8 Ohm and not 4 Ohm.

OUCH!!! It is 4 Ohm. I'll fix that right away. Thanks!

 

[splattergatz]

its probably ok
if it fails in like 3 weeks then you know why

I would add a heatsink to the chip if you can if there isn't already one there good luck

 

[mgkastra]

its probably ok

if it fails in like 3 weeks then you know why



I would add a heatsink to the chip if you can if there isn't already one there good luck

It has a huge piece of aluminum across it. The whole thing heats up to 1st degree burn temps.

 

[SamWhiskey]

Do you use the board in an original cab?
If not, make sure, one side of the speaker is not tied to GND.

Super Cobra uses a bridge amp. If one of the output pins is tied to GND, one of the opamps is permanently shorted to GND.
This will let the amp run hot, and will destroy it sooner or later.

 

[mgkastra]

Do you use the board in an original cab?

If not, make sure, one side of the speaker is not tied to GND.



Super Cobra uses a bridge amp. If one of the output pins is tied to GND, one of the opamps is permanently shorted to GND.

This will let the amp run hot, and will destroy it sooner or later.

I'll check my cab tomorrow. It's in a scramble cab that I wired myself, and uses a Jamma harness. I don't think I grounded the speaker but I'll check it out tomorrow.

 

[SamWhiskey]

Scramble uses the same opamp.

 

[mgkastra]

Scramble uses the same opamp.

My super cobra has a little sound board that floats on pins. Looks like this:

 

[SamWhiskey]

Ah, ok. Which amp is installed?

 

[mgkastra]

Ah, ok. Which amp is installed?

For both scramble and super cobra, I am using the on board amps

 

[SamWhiskey]

Which chip is installed on the subboard?

 

[mgkastra]

Which chip is installed on the subboard?

I can check it out tomorrow

 

[jpandbd]

LA4460.

I have 2 of these Stern 'URL boards' a moon war (37-81) and a Super Cobra (29-81). A970 19D192 Rev A

Counterclockwise to raise volume. Audio is always too loud and distorted no matter how low its set. I'm not an engineer by anymeans but I wonder if the 100K ohm VR is ill-matched or hmm?