Thanks again Ulli for your work and effort.Hi All,
many people are interested in this question: What is the best JFET for diy mic builders?
Find this useful info in the attachment and have fun
The classic 2N3819 was not in there. Would be curious to see how it stacks up.
Maybe but that's not really true. Mouser has them in stock right now.Could it be because it's discontinued by the brand-name manufacturers, and can only be sourced from so-and-so brands nowadays?
Like i said - so-and-so brands...Maybe but that's not really true. Mouser has them in stock right now.
https://www.mouser.com/ProductDetail/Central-Semiconductor/2N3819-TRE-PBFREE?qs=W/MpXkg%2BdQ4rsn8OhSyZOA==
If Mouser sells it, it's fine.Like i said - so-and-so brands...
It's not Toshiba/On semiconductors. Not to say they are fake, but many have tested these and they don't seem suitable for where the original part was used. They all seem to fall on the wrong end of specs.If Mouser sells it, it's fine.
I wouldn't lightly dismiss Ricardo's comment. He has more experience in his little finger than any one of us in our entire body. He's just a little grumpy from times to times.3. @ricardo: Sorry, but EIN is THE one and only criterium for noise spec. because it includes the gain of the circuit automatically. No question, the gain itself is influenced by the JFET Cin, but also the output noise. But this may be better visible without the noisy 1G resistors.
I try to clarify my point:I wouldn't lightly dismiss Ricardo's comment. He has more experience in his little finger than any one of us in our entire body. He's just a little grumpy from times to times.
Your test jig, with it's very low input capacitance, due to the elimination of Miller capacitance, clearly favours FET's with a very low intrinsic noise.
Many mic head amps don't have this kind of circuitry and favour low capacitance (particularly reverse capacitance) because it doesn't load too much the capsule.
One may argue that, in the 21st century there shouldn't be any condenser mic with a circuit that doesn't eliminate Miller capacitance, however, many are still in production, and not necessarily from cheap manufacturers.
Somewhat unrelated: how do you explain "NTE457 is highly claimed as „best performer“, as it's apparently the worst in your study?
It depends..In actual use, my externally polarized mics using K660 have not displayed any problematic self noise.
Of course, I've never used them to record a softly-played mandolin in an anechoic chamber . . .
I really don't mean to beat a dead horse. Ambient noise such as breathing of an artist will be orders of magnitude above the mic noise. Unless you are building some kind of sensor, or purely exercise electronics to get closer to the best theoretical performance this quickly stops making sense in real world application.Or the other way round, what amount of self noise is acceptable?
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