Bullet Mics And Capacitors

[unclej]

i just took in a little hand-held bullet mic being used for harp play that had quit working. the volumn pot was bad and after replacing it i got curious about adding a cap if you wanted to change the tone. it's got a regular 500k pot that's wired as follows: red wire from output jack to the right lug of the pot, red wire from the middle lug of the pot to the back plate. white wire from output jack to the back plate and then from the back plate to a ground lug and then from the ground lug to the left lug of the pot. simple stuff.

if you wanted to change the tone of the mic could you add a cap like you would on a guitar, would it have the same approximate effect as you changed the values of the cap and where would you wire it?

thanks

[thedoctor]

Boy, I would be careful and make no changes that aren't easy to remove. Try your tone circuit in a patch cord first because a lot of capsule mics don't take well to any standard capacitor toning. The 500k pot tells me you should start with a really low value (.0047).

[unclej]

thanks for the heads up doc..the customer didn't ask me to change anything so the whole question was one of curiosity and whether or not it would work. if you don't mind me asking another one what problems arise if you try to modify a mic in that manner?

[thedoctor]

The most common "capsule" mics are a high-imp lower that average output-capable dynamic. You can kill the output of these with almost anything added to the output circuit. I am surprised it had a three-wire volume pot, although it is 500k. Surely, this mic is always used with a decent preamp so modifications might be forgivable to an extent. I would prefer to do all tonal-mods at the pre/mixer.

[mledbetter]

The most common "capsule" mics are a high-imp lower that average output-capable dynamic. You can kill the output of these with almost anything added to the output circuit. I am surprised it had a three-wire volume pot, although it is 500k. Surely, this mic is always used with a decent preamp so modifications might be forgivable to an extent. I would prefer to do all tonal-mods at the pre/mixer.

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Generally those bullet mics are run straight into a guitar amp.. Most of the time i've seen them used live they are even overdriven.. A friend of mine used to have one and they take a beating. They aren't very sensitive as they are expecting you to have the harp touching it and all the airflow going straight through it..

[lovekraft]

You could rig up a test jig in a box with two jacks and a socket for the cap (or several caps and a rotary switch, a la a varitone) - route the mike through it and you can try any cap you like. I'd start even smaller than was previously recommended, around 2200pF, and try about a decade or so either side of that to see if you get anything useful. But that's just me!

[unclej]

thanks again for the info..like i said..this was just a curiosity question not something the customer wanted. i play blues flute through a similar mic but run it through a danelectro fish & chips equalizer to get the tones that i want and now would recommend that to anyone that asks.

besides, wasn't this more fun than another p90 question?