mic volume inline?

[stuee]

Hi I have a pair of wireless microphones that use one base receiver and 1 chanel mono out. I would like to put a potentiometer inline of the output to control the volume 0 > 100% or even better a digital with a 5 bar led and button up and down. I do have a 12v and 5v power source.
I have attached the specs for your perusing.

Thanks

 

[audioguru]

The output level is greater than 25mV but they do not say how much greater. An ordinary mic has an average output level of about 10mV.
A volume control for this tiny level might add noise. Usually a mic is pre-amplified to feed a volume control.

There are a couple of digital volume controls available. An LM3915 is a popular LED bar graph driver IC.

 

[stuee]

Thanks Audioguru.
Can you tell me if i can put a potentiometer on it and if so which ones to try,
thanks

 

[audioguru]

Doesn't the mic's receiver feed a preamp or audio amplifier? Doesn't the preamp or audio amplifier already have a volume control?
The output from the preamp can feed an LM3915 bar graph IC.

 

[stuee]

No bacically, its a wireless mic setup with 2 mics both going to the same mono jack output which i want to feed into the line on on my pc and use through that,.
I want a control on it so when karaoke is playing on the computer to my stereo i dont need to mess around opening mic volume and adjusting. Ideal i would be good just having the line in at 75% then control the line in from the mic receiver.
If that makes sense

 

[stuee]

im happy just to have the analogue control on it too so not bothered with the digital control at this moment

 

[alec_t]

If the PC sound-card has AGC it may automatically over-ride the effect of an external volume control.

 

[audioguru]

Buy a 10k ohms volume control with an audio taper (logarithmic). Do not use a linear potentiometer. An audio volume control will probably be marked "10k A" and a linear pot will probably be marked "10k B".
Connect one resistive terminal to ground, the other resistive terminal to the output from the receiver and the slider to the computer audio input. If its wires are longer than a few inches then they must be shielded audio cable or they will pickup mains hum.