Potentiometer problem with understanding

[ItysNotMe]

Hello, I have a 2 gang 10k audio taper pot. It is a mini pot - (blue with no online data) whatsoever! I measured the resistance between the pins on both (gangs?) The resistance varied from one to the other. Also there are no numbers on it and no online data to be found!

I assume that the ground goes to the ground sleeve on my stereo output jack? Does it also go to the board and ground? (I also assume it does?) , So from what I am able to find out is that a pot has pins 1, 2 , 3. 1 being the ground , 2 being the output - (wiper) to the output jack , and 3 coming from the output of the circuit feeding through the pot?

Please correct me or confirm me if i am correct! Thank you very much for your help!

The very bottom print is the one that I have built and cannot figure out how to connect the 10k pot/s to it! It is the one that is laid out in many different colors showing the capacitors-(yellow, red etc), pot, etc. at very bottom of that pdf page!

Here below is the link to the one that i have built and I cannot seem to get the pot to work properly!

https://www.electro-tech-online.com...tereo20Electret20Microphone20Preamplifier.pdf

Thank you very much in advance for your help!

 

[Mike odom]

I'm not much of an audio buff, but I'm not a noob either. Looks to me like you have a couple of problems:

1) you're trying to use an opamp as an audio amplifier. While opamps are GREAT for the front end, they don't drive any power, most rated less than 20mA on the outputs, and the TL072 output swing is 13.5V into 10k = about 1.35mA.

2) It looks like what you have constructed is a preamp, that needs to drive the log taper pot, the center tap of which needs to drive an audio amp (Like the LM386 or the TPA6138)

 

[ItysNotMe]

Okay , so are you saying that I could simply just replace the TL072 Op-Amp with the LM386 and all would be well? Or do I need a different circuit all together? I am thinking on possibly using an amplifier on the mic's output through cables after it leaves the preamp. But I will say that if I can serve the purpose with the LM386 amp, I would rather keep going in the direction that I am heading.

This needs to supply plug-in voltage (not to be confused as phathom power which is much higher in voltage than what I need) going to the stereo electret mic ; (that part is very crucial) in order for my mic to function!

Thanks!

 

[Mike odom]

there are lots of threads on here describing just such a thing... here's one:

https://www.electro-tech-online.com/threads/intercom-how-to-explain-the-circuit.120070/

you can look at the LM386 data sheet to get a better idea of component values and design ideas.

 

[ItysNotMe]

This is not my design as far as me owning it. It's one that I found on line. I looked at the circuit that you recommended and I will probably use that either now or later on. I probably just need a pre-amp for my purposes right now. The designer of the circuit that I presented seemed to have made it work , I guess?

If all I currently need is a battery box to supply my electret stereo mic ; is the 10k pot a problem for it? Would it be better just to put a fixed resistor in the place of the pot? If so ; what size of resistor would you recommend? Thank you again for all you're help!!!