Georgia Fiero Club Forum
All Things Fiero => Tech Tips, Tech Questions => Topic started by: f85gtron on February 23, 2015, 04:17:07 am
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I've installed the premium sound sub, but used a new amp. I'd like to adapt the premium sound slider to work with the new amp, but am having difficulty figuring out how to go about it. It appears to be a normal volume pot, but the original schematics show it controlling the voltage to the amp board. The new amp is all surface mounted components and i don't have the patience for soldering those, so that's out the window.
I wonder if the pot could handle straight volume control from the radio feed? I don't want to burn up a 30year old hard to find component.
Ron
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The 'slider' is a 10K Ohm linear pot and you are right about its function. It adjusts the bias voltage to the power transistor in the amp.
If you were to go inside the radio you would have to find the pre-amp outputs. I seriously doubt that this pot will withstand the mains amp output.
Also, just hooking it up to the pre-amp would only control the volume. You would need a low-pass filter at the input of the slider and there goes your input power to the sub-amp.
It's best to repair the stock sub amp. 99% of the time the problem is that the heat sink compound on the main power transistor dries up and the transistor overheats and self-destructs.
I have a few of the correct power transistor laying around and can change it and apply new heat sink compound.
Most folks just add a different amp and forego the stock level adjuster for one that matches their new unit.
Just a thought.
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Roger, do you have any idea what the output of the sub amp is?
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I believe it's 20 watts. I'll have to go back and check.