How do I boost the audio output?

[Zero999]

This is ridiculous. You can purchase audio amps on eBay for $12. With 24V 3A power supply, you'll get plenty of boost.

And that would be a ridiculous idea. The original poster requires a signal, not a power amplifier.

If it's a ready built solution the OP is looking for, then he should search for a pre-amplifier, not a power amplifier.

See the circuit attached. I use two resistors to create a virtual ground, as I use a single 9v battery,  as suggested by BilliyO

you will either have to use a split supply or create a virtual ground at Vcc/2.

As I mentioned, it seems to work when I connect it to the output of my laptop, but not to the receiver....

PS:
Apologies for the quality, I will try to get some software do depict schematics

It sounds like an issue with loading. The rail splitter has an equivalent resistance equal to both of the resistors connected in parallel, which is 1k. This isn't a problem, at DC, because they only carry the tiny bias currents, but at audio frequencies, the voltage will bounce around, when the circuit drives a small load. Adding bypass capacitors will reduce the impedance of the ground node considerably, by charging and discharging as the op-amp's output swings between positive and negative.

A couple of other notes:

I would recommend adding another resistor to limit the gain to a maximum level, otherwise it'll make the potentiometer difficult to adjust and it very easy for the op-amp to be driven into saturation.

I've added labels to denote the voltages in the circuit, with the all important 0V node, the point from where all voltages are referenced to.


EDIT:
Is this a stereo amplifier?

Why use the old LM741? It's pretty noisy and doesn't work well off such low voltages.

It would be better to use the TL074. One op-amp for each channel, with the other as a rail splitter. The spare op-amp could be used to boost the rail splitter circuit and reduce the impedance, without big capacitors.

[Epovo]

Thank you all very much. I found out what was going wrong - It was a rookie mistake (the kind I do) with the connectors 

[tooki]

Thank you all very much. I found out what was going wrong - It was a rookie mistake (the kind I do) with the connectors 

Namely…?

[EPAIII]

If you want to learn about OP Amp circuits and how to design them, try

The OP Amp Cookbook, by Walter G. Jung.

It is somewhat old, but the basics do not change, just the IC part numbers. And even the classic 741 still works today. I have made line amplifiers like you want with them many times. It can have a high impedance input and can supply enough current at the output to drive almost any audio input, which should be high impedance.

And if your 741 circuit lacks performance in some area, there are many, many OP Amps with the same pin-outs and better specifications that can be plugged into the same socket as the 741 to provide better performance. I have started with a 741 many times and pulled it and just substituted a better one. That works quite well for audio circuit design.

But you gotta have a dual (+ and -) supply or make a virtual ground in your circuit. And if you use a single supply, it (the supply) can't share a ground with either your input device or your output device.

https://nortonsafe.search.ask.com/web?q=op%20amp%20cookbook&ssdcat=321&lang=en&source=nag&year=2015&locale=en_us&geo=us&version=22.23.10.10&plang=sym:en&buildname=retail&heartbeatid=4ae3d98c-56e4-4df2-adf1-00b1d085e47e&eapenabled=false&env=prod&vendorid=1014930&plid=866&plgid=41&skup=21389648&skum=21376863&skuf=90001202-fa&endpointid=4ae3d98c-56e4-4df2-adf1-00b1d085e47e&lic_type=2&lic_attr=17059858&psn=7jjxx287wjvq&templatecat=sbu_w_1000_5039_n360dsp_retail&schemacat=sbu_w&schemaver=1.0.0.0&olpchannel=retail&osvers=10.0&oslocale=iso:usa&oslang=iso:eng&os=windows&showuninstallsurvey=1&installstatus=updated&vendorsrc=firefox&machinelocation=us&sw=0&3in1=0&npw=0&hp=0&dsp=0&cdest=nag&annot=false&vendorConfigured=ask&o=APN12178&prt=ngc&ver=3.21.0.6&tpr=111&chn=1014930&guid=4ae3d98c-56e4-4df2-adf1-00b1d085e47e&doi=2023-11-26&browser=FireFox&prod=DS&doi=2023-11-26&installSource=nag&cmpgn=oct23&darkMode=false&sameTabLaunch=false

Thank you @alligatorblues. I know I can buy it. I am doing this in part to learn something.

[alligatorblues]

This is ridiculous. You can purchase audio amps on eBay for $12. With 24V 3A power supply, you'll get plenty of boost.

And that would be a ridiculous idea. The original poster requires a signal, not a power amplifier.

If it's a ready built solution the OP is looking for, then he should search for a pre-amplifier, not a power amplifier.

EDIT:
Is this a stereo amplifier?

My point is the futility of reinventing the wheel again and again. If all the OP wants is a SIGNAL, what is he going to do with that? Given the choice of designing and building a one-off  integrated amplifier, or purchasing one for $12 is pretty much a no-brainer. I can only assume people are ignorant to such solutions. Rather than perpetuate it, I make rational suggestions.

I once purchased a board amp, installed it in an enclosure, put connectors on for Power, Signal, Speakers, Volume; connected it to a PC, and it kicked ass. The entire sound system cost about $50, and took about 3 hours to make. Do certain people have an aversion to saving time, effort and money. I sold that system 3 years later for $187+ some cents.

Blanket advice to everyone seeking an electronics project: stop reinventing the wheel! Don't use Arduino. Don't purchase kits. Don't pay outrageous prices because it isn't available anywhere else. Because it is. You just have to look. I needed a 1.0 Ohm resistance standard +(-) 10ppm. I purchased a L&N off eBay. I spot welded a ~3/4" ( 19mm) length of Manganin that I annealed  until its tempco was about 1.000008 per meter.

I spot welded that wire in parallel with the existing resistive element, and it's been hanging off my 34420A for weeks. It is +-10ppm, period. So, I took a $70 resistor, gave it a littler tlc, and now I have a $2500 resistor.

If you're going to invest the time, effort, skill and money; for the love of all that is good in this world, gain something tangible for your effort. That reminds me of one of the best kept secrets in the world! No matter how interested chicks pretend to be in a man's work skills and accomplishments, their sole interest is how it translates to income. Which reminds me of another one of the best kept secrets in the world.

Since most guys can't just pick the hottest chick in view, take her home, and have sex; guys never get a chance to learn; No matter how hot the babe, you'll get sick of her just as fast.   

[Zero999]

My point is the futility of reinventing the wheel again and again. If all the OP wants is a SIGNAL, what is he going to do with that? Given the choice of designing and building a one-off  integrated amplifier, or purchasing one for $12 is pretty much a no-brainer. I can only assume people are ignorant to such solutions. Rather than perpetuate it, I make rational suggestions.

I once purchased a board amp, installed it in an enclosure, put connectors on for Power, Signal, Speakers, Volume; connected it to a PC, and it kicked ass. The entire sound system cost about $50, and took about 3 hours to make. Do certain people have an aversion to saving time, effort and money. I sold that system 3 years later for $187+ some cents.

Blanket advice to everyone seeking an electronics project: stop reinventing the wheel! Don't use Arduino. Don't purchase kits. Don't pay outrageous prices because it isn't available anywhere else. Because it is. You just have to look. I needed a 1.0 Ohm resistance standard +(-) 10ppm. I purchased a L&N off eBay. I spot welded a ~3/4" ( 19mm) length of Manganin that I annealed  until its tempco was about 1.000008 per meter.

I spot welded that wire in parallel with the existing resistive element, and it's been hanging off my 34420A for weeks. It is +-10ppm, period. So, I took a $70 resistor, gave it a littler tlc, and now I have a $2500 resistor.

If you're going to invest the time, effort, skill and money; for the love of all that is good in this world, gain something tangible for your effort. That reminds me of one of the best kept secrets in the world! No matter how interested chicks pretend to be in a man's work skills and accomplishments, their sole interest is how it translates to income. Which reminds me of another one of the best kept secrets in the world.

Since most guys can't just pick the hottest chick in view, take her home, and have sex; guys never get a chance to learn; No matter how hot the babe, you'll get sick of her just as fast.   

What a bizarre rant.

Exactly how does that help the original poster, with boosting the signal level of a wireless microphone, to the level required for the auxiliary input of a soundbar?