"Phantom power 4 mic. "

This is the place for any magazine-related discussions that don't fit in any of the column discussion boards below.
Post Reply
User avatar
dacflyer
Posts: 4451
Joined: Fri Feb 08, 2002 1:01 am
Location: USA / North Carolina / Fayetteville
Contact:

"Phantom power 4 mic. "

Post by dacflyer » Sat Jun 15, 2002 8:58 pm

i have a small portable amp ( 1 watt ) use for various things,, it works great on dynamic mic.s
but it will not work a electric mic, someone told me they need power to make them work,, but these electric mic.s only have 2 leads,,
i need a schematic of sorts to make a small adapter that i can plug inbetween the amp and electric mic..anyone got a idea? i was told also that the adapter could power most any mic too dynamic mics too.. thanx for feedback..no pun !

viveguy
Posts: 37
Joined: Wed Feb 06, 2002 1:01 am
Location: Grand Rapids MI
Contact:

Re: "Phantom power 4 mic. "

Post by viveguy » Sun Jun 16, 2002 6:42 am

It sounds like you are using what is known as an 'electret'microphone capsule.If so,there is a JFET in there that needs to be biased.You can do this by applying 1.5 to 5 volts dc to the high side lead,the other lead being (-) or ground.You should also put a series resistor in for current limiting say around 2.2K or higher.The other thing you need to do is ac couple the output with a capacitor of about .22uF or higher,depending on your low frequency response needs.
You can get more info and schematics at epaorama.net,Digikey or,planetee.com.PlanetEE is the online service for Electronic Design magazine.Look in the archive of the "Ideas for design".This is a monthly competition they run for simple or alternative circuit ideas.<p>Regards,
AL

User avatar
Externet
Posts: 1838
Joined: Fri Feb 01, 2002 1:01 am
Location: Mideast USA
Contact:

Re: "Phantom power 4 mic. "

Post by Externet » Tue Jun 18, 2002 8:08 am

Hello Dacflyer.<p>The electret condenser microphones take a little power via the same lead the audio exits. Isolating the audio and power is done with a capacitor and a resistor.
Here is a great place to dig deeper :<p>http://www.hut.fi/Misc/Electronics/circ ... ering.html<p>Miguel
- Abolish the deciBel ! -

User avatar
dacflyer
Posts: 4451
Joined: Fri Feb 08, 2002 1:01 am
Location: USA / North Carolina / Fayetteville
Contact:

Re: "Phantom power 4 mic. "

Post by dacflyer » Wed Jun 19, 2002 3:05 pm

thanx guys..

Post Reply

Who is online

Users browsing this forum: No registered users and 9 guests