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May 28, 2024, 01:14:00 PM

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Orange crush 20L - what is the purpose of the jfet before the power amp

Started by belab, January 01, 2024, 03:15:24 PM

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belab

Hi,

what does Q1 jfet do at the input of the power amp?

schematic

Thanks
belab

Tassieviking

I will take a wild guess that it is there as a delay so there is no big pop as the amp is turned on.
The 1uF cap C25 is slowly charged up through the 10M resistor R45 until it turns the  Jfet on and allows the signal through. But I could be wrong.
There are no stupid questions.
There are only stupid mistakes.

belab

Thanks, my guess was similar.
Happy new year! :)