Thursday, 14 February 2013

Dragonfly Valentine

Happy valentine's to everyone. Please remember to care for your missus or girlfriend between builds too...


3 comments:

  1. Right, this is working in a very strange way. Without the JFET it works but it's fairly quiet, with a 2n5457 with the legs twisted it doesn't work but that what the pinout says, I've checked the scheme and your layout definitely uses the correct pinout. Here's where it gets strange, I'd I put the 2n5457 in with the legs as normal, dsg, then it works but sounds like it's poorly biased, if I take the gate leg out then it works great and it's got a decent volume! WTF is going on? I'm guessing that I've just screwed something up but I'm off out to a gig so I've not got time to investigate, any ideas?

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    Replies
    1. I think it's just a biasing problem. Can you try breadboarding the 3K resistor going to Q2 drain? I believe a custom, suitable value there should gine you an answer..
      +m

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    2. Sorry for the late reply dude, I was feeling a little partied out after last night :D I think you might be right as I used a 3k3 in place of the 3k, though it still doesn't explain why it's not working when I twist the legs of the jfet to match the layout's pinout (which is definitely correct) but when I leave the legs untwisted it works?!! I don't know, I've gone over the layout a couple of times but my hungover eyes may be playing tricks on me. Anyway I've just got an SM57 which is itching to be played with!

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