In Desperate Need of NPD5566

Hi Folks,

Moderators, forgive me if I am posting in the wrong forum. I am in desperate need of four (4) NPD5566 / 2N5566 dual-fet's for a repair for a friend. Have tried the google parts-mining route to no avail; I don't care about the cost (within reason;)) - I am not looking for freebies, as I do realise that this stuff costs. Please, if anyone has a handful in their parts drawer that they don't mind selling, I would be eternally grateful. In turn, I have a pretty comprehensive parts collection, and am always willing to help out a fellow d.i.y'er, plus I have an enormous schematics archive of things that just aren't available in the usual public domain & am always willing to share. Thanks!
Wonder why you think the original jfets need replacing?
I have no idea of a source of those particular National Semi parts.
google shows them being sold through Aliexpress. I have never used that service myself.
Might have to sub something else from Linear Systems, lsk389,lsk489? need to check pinouts.
Recently found this supplier for Linear,
I am looking at the specs for 2N5566,
Idss = 5 - 30mA
Vp = 0.5 - 3 V

Good Luck
Last edited:

Mark Johnson

Paid Member
2011-05-27 3:27 pm
Silicon Valley
Linear Systems says their LS844 is an acceptable substitute, see image.



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Thanks for the help all! Will try the aforementioned sources. As for this being the suspect part, evidently these amps are known to cook these dual-fets and an associated zener fairly regularly, causing symptoms such as moderate offset (1.3 vdc), and loud intermittent transient pops in the affected channel, which is what this amp is doing. Also, amp was completely recapped already, and the outputs and drivers replaced previously with matched pairs.