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Hi z
May 2, 2015 19:46:56 GMT -6
Post by dandeurloo on May 2, 2015 19:46:56 GMT -6
Mark can you explain what kind of things happen in a Ldc with poorly designed or dirty hi z sections? Like what kind of noises and things would happen.
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Hi z
May 3, 2015 14:33:41 GMT -6
Post by markfouxman on May 3, 2015 14:33:41 GMT -6
Dan,
The Hi Z section is probably the most crucial part of any condenser microphone. Here we have two enemies--parasitic capacitance and parasitic resistance. The capacitance will load the signal, reduce output and increase noise. It can come from long wiring, PCB layout, even from running wires from the capsule in parallel.
The resistance can be result of dirt between traces or soldering flux residue. Any hygroscopic material there will absorb moisture and result in resistance decrease. You can get poor bass and increased noise/hiss.
The best way to deal with that is thoroughly clean the PCB after soldering with flux remover and use conformal coating to protect exposed contacts/traces from moisture or conducting dirt. Make the wires from the capsule as short as it is practical and never run them together and/or in parallel.
Best, M
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Hi z
May 3, 2015 14:48:22 GMT -6
Post by dandeurloo on May 3, 2015 14:48:22 GMT -6
Mark can it make the mic have random crackles and snaps. It sounds almost like a bad tube? I am in the middle of trouble shooting a mic and I have ruled out the tubes and I have cleaned all the hi z stuff I can see. My guess is it is layout or some hi z area I can't get to.
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Hi z
May 3, 2015 14:49:15 GMT -6
Post by dandeurloo on May 3, 2015 14:49:15 GMT -6
BTW, I have said it hear and on GS a number of times. I love the work you have done on my ribon mics and your mics sound amazing!
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Hi z
May 3, 2015 15:41:55 GMT -6
Post by markfouxman on May 3, 2015 15:41:55 GMT -6
Mark can it make the mic have random crackles and snaps. It sounds almost like a bad tube? I am in the middle of trouble shooting a mic and I have ruled out the tubes and I have cleaned all the hi z stuff I can see. My guess is it is layout or some hi z area I can't get to. The capsule itself can give that kind of noise--some random discharges. First, test it for "moisture pass". Take it up close and breath into it a few times. If it shorts for awhile then that's the problem. Try to swap the capsule with a known good one to completely rule it out. Best, M |
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