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Re: Something's cooking in my Kustom Kitchen... [message #25474 is a reply to message #25469]

Thu, 25 August 2016 06:16

stevem
Messages: 4735
Registered: June 2004
Location: NY

Senior Member

Using the amp with the added speaker dropped the load on the amp to under 8 ohms , and this assumes that the 2-12" cabinet is still wired for a 8 ohm load !
When you run any solid state amp on a load under its design minimum you cut the amps output power in half and you also make the amp run twice as hot for any given volume level you play it at!!!!!

I am concerned that you said it smelled hot!
These amps have a Thermal circuit breaker in the output section that shuts the amp down once the output transistors get above 182 degrees , and it sounds like you where right on the edge of that when you turned the amp off!!

The inputs on these metal face ( 1971 to 74 ) amps do not have a different tone, the set up a different gain level / volume out of the preamp section on each channel of the amp .
These amps use plug in connectors from board to board and the likely cause of the amps record out Jack not working is the tarnish that forms on these connectors from age .
Many times all that's needed is to unplug them and carefully plug them back in a few times .
Wiping some light oil with a Q tip on the Male pin in each connector will keep tarnish from coming back for a long time!
If you must run that added speaker cabinet than get that recording output Jack working, feed that signal into a poer amp and then into that other cabinet !

If you play the amp up loud thru a 8 ohm cabinet for 45 minute and its solid , then concider yourself lucky that you did no damage with running the two cabinets.
Just note that it's always fully safe to run a solid state amp on a higher impeadance load , you will have the same 50% loss in output watts but the amp will run cooler, not hotter!

[Updated on: Thu, 25 August 2016 06:18]

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