On Sun, 23 Nov 2014, marc wrote:


Hello,

I fit a 3 pin plug and tried some transistors ..

I get a good result with a C369 ...

Any comments?

I did not find my stock replacements, but have a box of spare parts from
?? all kind of old electronics ... ;-)


If the replacement isn't a jfet, it won't work at all. That "C369" sounds
more like a bipolar transistor, and if you get "good results", it's only
because the transitor is letting the signal pass through. It can't
amplify, bipolar transistors need forward biasing, and that's not there
since the transistor is supposed to be a jfet.

If you do a search, the need to replace that front end jfet (I'm assuning
that's where the part is) is fairly common, so there are various people on
the web writing about replacing it. I think they've often used an
available jfet, which won't be optimum, but will work better than a
bipolar transistor.

Michael