No I didn't measured the Muse BP 22uF nor the 4,7uF...
Does a bad-biased jfet can influence the tone ? (my lack of bass & level)
Now the 2 mics are "online" and I can notice a 4,6dB level difference
SE Electronics Z3300a
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Does a bad-biased jfet can influence the tone ? (my lack of bass & level)
Now the 2 mics are "online" and I can notice a 4,6dB level difference
the 1GΩ after the 1nF must go straight to ground.
Yes
Ok but in the original schematic it doesn't... R10 is 3KΩ in original t.bone
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I explained to you many times that the stock, Chinese scheme put R10 to make a kind of self-Bias. Be able to use almost any Jfet, without manual BIAS, individually, for each mic.
Lower performance is achieved, but profit matters.
the correct non-mutilated circuit, as in U87
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sorry... lot of things to learn later on, to digest... and jfet are soooo specials !
https://sound-au.com/articles/jfet-design.htm
It is possible that your audio build to the second microphone on the bread-board introduces parasitic capacitances to the jFET input side, which at the huge impedance introduce signal and high frequency attenuation, just like the km84. We are talking about a few pF!
In km84. C9=15pF introduces an attenuation of -10dB!
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I hope my audio board doesn't mess up the mic...
Anyway I will rebias the 2 mics tomorrow with a RV for R9 and no R10... and also find some good tutorials on REW to understand clearly what & how to do with this software
Anyway I will rebias the 2 mics tomorrow with a RV for R9 and no R10... and also find some good tutorials on REW to understand clearly what & how to do with this software
#27
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Post in thread 'Two microphones as matched pair, what properties are matched?' https://groupdiy.com/threads/two-mi...hat-properties-are-matched.84151/post-1092481
It's not the level difference that bothers me (it can be adjust by gain at recording) but the sound difference. The Orig-mod has more body, more detail when the Mod is thin, less caracter...
Let me rebias the fet and I'll be back with (I hope) good news
Let me rebias the fet and I'll be back with (I hope) good news
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You can try to change the capsules between them.
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you can even swap jFETs between them
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Are transformers both wired identically?
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you can even swap jFETs between them
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Are transformers both wired identically?
Yes I could... (I will if no update by re-biasing)
Yes in "A" mode
Have you had a look at the link about Jfets ? I found the guy's explanations very interesting...
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I have been following Rod Elliott (ESP) for many years
No... solder / de-solder /re-solder > I'm gonna ruin the boards...
I'm gonna find a solution for matching (I just read the topic > no matching mics, just as close as you can find) the 2 mics in term of sound, color, etc...
Anyway, one of the 2 I bought second-hand was "haunted" since the begining (Tr out-of-order !) so if I can't fix the problem I'll have to buy another second-hand and work on it (changing capacitors & biasing the fet). I think the "Mod" is a mic that has lived a turbulent life befor I got it...
You can very easily change the wires of the capsule, reverse Front with Rear, maybe the front membrane has problems.
If it sounds thin check if C6=47nF is connected.
