# Pineapple JFET Biasing?



## overdriver999 (May 2, 2019)

hello i am just before boxing up the Pineapple and i am familiar with using the trimpots to bias the jfets from a similar pedal i built years ago..i didn't notice any instructions on how to bias it or what voltage to trim them to in the build document.can anyone point me in the right direction of the info on this? which jfet to test? and at what voltage to stop at? or does everyone just set them by feel/sound?


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## tdukes (May 3, 2019)

I biased mine by feeding it with a 1k 1v peak to peak sine wave and adjusting the trim pots until I thought the signal looked "pretty" on my oscilloscope at the associated jfet. I am sure there is a better way.


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## overdriver999 (May 3, 2019)

tdukes said:


> I biased mine by feeding it with a 1k 1v peak to peak sine wave and adjusting the trim pots until I thought the signal looked "pretty" on my oscilloscope at the associated jfet. I am sure there is a better way.


that's probably a good way to do it but that's not an option for me..i just have a multi meter..i appreciate your reply.


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## overdriver999 (May 5, 2019)

overdriver999 said:


> hello i am just before boxing up the Pineapple and i am familiar with using the trimpots to bias the jfets from a similar pedal i built years ago..i didn't notice any instructions on how to bias it or what voltage to trim them to in the build document.can anyone point me in the right direction of the info on this? which jfet to test? and at what voltage to stop at? or does everyone just set them by feel/sound?


UPDATE:SOLVED
You have to put the multi meter on the drain leg of the 5th and 6th jfet and check voltage...i set mine to the pinnacle voltage,roughly,which is 
Q5 : 4.18
Q6 : 4.19


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