2N3819 Replacement

[inefficiency]

I'm trying to find a replacement for the 2n3819 JFETs in Fdecks HPF found here.

I have a couple of 2N5485s here. Will they work?

Any help would be appreciated.

Cheers!

[inefficiency]

Also, more likely to work: I have a pair of 2n3820.

[IvIark]

Any of them could work but you may need to alter a couple of resistors to get it to bias.  Basically you need to try it and see

[inefficiency]

Cool, thanks.

Will the datasheet(s) give me any evidence to how much of a change I will need?

I imagine the 2n3820 will probably be the safest bet.

[IvIark]

No, that's the problem with JFETs, it's difficult to predict the requirement which is why the are often matched for phasers, or used with a trimmer in drive pedals.   I'd socket the 2K and 3K3 drain resistors so you can tweak them.

[inefficiency]

Ok, will either do that or grab a couple of trimmers. Any recommendation on what value trimmer to get? 5k or something?

[IvIark]

Yes 5K for both would be perfect I suspect, maybe 10K to give you a little more if required at the expense of some resolution

[inefficiency]

Cool. Thanks again Mark!