Here is a great video from Synth DIY Guy on Passive Utilities that he calls “Pocket Passive Patch Pals”
Enjoy!
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Yeah, I was going to make the JFET delight but then I forgot… Thanks for reminding me!
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I saw this for the first time just last week! His videos are a lot of fun (he hides these things in plastic Eostera Eggs!)
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I’ve tried it but couldn’t make it work… using 2N7000 jfet. Maybe It’s The wRONG part. Anyone else had success? All I want is a simple vca that will work with LMNC’s envelope generator (his strip board layout with a trigger in, manual button and cv out). Cheers
I can confirm that works with the 2n5457.
Around $2 here: https://www.pedalpartsaustralia.com/index.php?main_page=product_info&products_id=2052
I wouldn’t rely on this as a primary vca though - it pretty limited even combined with an ADSR.
Let me know if you want any sound clips or a layout of my build
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JFET specs aren’t very precise, so depending on the circuit and how easy it is to trim e.g. bias voltages, getting it to work or not may depend on the component batch.
(also pay attention to pinouts if you try different transistor types)
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Hi F
Do you think I was just lucky with my 2n5457 transistor?
Marc
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Looks like that’s what was used in the video, and if it works it works 
but 1) JFET parameters like Vgs and Idss vary widely (see here) and 2) they’re no longer made in TO-92 (*) and there are known fakes out there (they’re popular with stompbox folks so there’s a market), so if you bought them in the last 5-10 years you (or the synth DIY guy) may have ended up using something else…
*) The SOT-23 version MMBF5457 is still made.
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Yes, I had some of those 2n5457’s left over from pedal building around 15 years ago.
Didn’t know they were so hard to come by - or that there were knock-offs on the market. So thanks for suggesting a replacement part.
Pedalparts is a reputable company though so I think you’d be okay with them.
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Hmm, I seem to have three 2N5457 TO-92s left out of 10 I bought from Mouser in 2010. Maybe I should start an auction.
Edit: Four. Just found another one. On the floor. Under my foot.
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