Audio Amplifier Basic Circuit Build Demo with Volume Control

[@W1RMD]

Thanks for the great video! I always learn from your videos no matter how simple or short they are. Still, way cooler through a vacuum tube!

[@AllAmericanFiveRadio]

Thank you.

[@ramachandran8666]

Thank you Rick for some useful information however basic it may be. I have been around electronics and hardcore science for over 50 + years but there is always something new I have learned that I did not know or forgotten which was the case for why and when one uses the volume control at different stages in an amplifier

[@AllAmericanFiveRadio]

Thank you, and your welcome.

[@skycarl]

Nice demo Rick. Showing both positions and why helps understand the whole setup. Thanks buddy for sharing.

[@AllAmericanFiveRadio]

Hey Carl, Thanks, hope you are doing well. Every time I think something is to simple, I'm wrong.

[@gime3steps]

Awesome illustration, thanks!

[@AllAmericanFiveRadio]

Thanks.

[@listerine-pr5lt]

Thanks ,Very Useful.

[@AllAmericanFiveRadio]

Thank you, and your welcome.

[@johnb7805]

Mr. McWhorter may I ask how you choose you dc Q-point condition for your transistors and your resistor and capacitor values or I guess in other words your operating conditions. Thank you again for your awesome videos and I hope your health issues continue to improve.

[@AllAmericanFiveRadio]

Thank you. All I did was install a Variable resistor and adjusted it until the signal was clean, using an oscilloscope. The feedback circuit I tried 100,000 ohm resistor at first and it did not work, so I tried a 10K ohm resistor, and that showed me I was going in the right direction. Then to improve the feedback I tried several different capacitors and settled on the 0.022 µF because it worked the best. This still took several hours to do. Thanks again.

[@rádiosantigos1958]

Nice explanation! Thanks.

[@AllAmericanFiveRadio]

Thanks.

[@adaminsanoff]

Sir, your speech is music for the ears.

[@AllAmericanFiveRadio]

Thank you.

[@dicko195]

Very nice info, thank you

[@AllAmericanFiveRadio]

Thanks.

[@LousyPainter]

Great information! Thanks.

[@AllAmericanFiveRadio]

Thank you, and your welcome.

[@twobob]

No nonsense. Approved

[@AllAmericanFiveRadio]

Thank you, and your welcome.

[@stewartrv]

What are the pro's and con's in having a two stage amplifier like this as opposed to connecting the same two transistors as a darlington pair?

[@AllAmericanFiveRadio]

The pro's, very sensitive. The con's, not linear.

[@stewartrv]

@@AllAmericanFiveRadio OK thanks for the update!

[@warplanner8852]

..and the obligatory question: how about matching the output impedance to an 8 ohm speaker or headphones?

[@AllAmericanFiveRadio]

Google audio transformer calculator

[@adityarajesh631]

how do you give input to the preamp ..... like how do i feed a music into it ... i want a cheaper way to implement it

[@AllAmericanFiveRadio]

Some have used a Phone. Speaker connection from a radio, earphone connection from a DVD player.

[@cedarcottonwood2988]

Very good

[@AllAmericanFiveRadio]

Thank you, and your welcome.

[@alienforce7688]

Can anyone please recommend a book for learning how design and build a small format mixingdesk based only on transistors ? Please .. just so i can get started i have built some DIY synths before and want to make the next step.

[@AllAmericanFiveRadio]

I GOOGLED "audio mixing circuits" and found quite a lot of information. I also when to AMAZON and searched the same thing "audio mixing circuits" and found five or six books on this subject.

[@ahsheng1832]

Hi do you know how to add in the mute function for this?

[@AllAmericanFiveRadio]

You can download the lafayette LR 200 schematic it has a Mute circuit. www.hifiengine.com/manual_library/lafayette/lr-200.shtml

[@umairrafique9787]

CAN I CONNECT A MIC AND A SPEAKER . WHAT WILL THE IMPEDENCE OF SPEAKER? PLZ REPLY.

[@AllAmericanFiveRadio]

For a microphone you would need one or two more stages in front. You could use a transistor transformer on the output. Simple Microphone to Speaker Amplifier Circuit www.circuits-diy.com/simple-microphone-to-speaker-amplifier-circuit-2/

[@JasonTHutchinson]

Can you add a tone control?

[@AllAmericanFiveRadio]

Yes. Might make an interesting video. Thank you, and your welcome.

[@aak6126]

Its showing same wave at output as input in Proteus.

[@AllAmericanFiveRadio]

But not the same amplitude.

[@aak6126]

@@AllAmericanFiveRadio bro amplitude is also same

[@AllAmericanFiveRadio]

Nop. Audio Amplifier Basic Circuit Build Demo kzbin.info/www/bejne/m56rZ3igbKxnhNE

[@Madness832]

4.3k resistors?

[@jp040759]

Better transistor bias point for the transistors so signal isn't clipping on one peak of the signal way before the other peak clips. Ideally the Voltage at both tranny collectors should be 1/2 power supply voltage or 6 volts in this case.

[@AllAmericanFiveRadio]

That value made the best sine wave. Biasing an Audio Transistor kzbin.info/www/bejne/gaW7dmqpaqmfmas

[@rods6405]

No Dc Block cap at output or 4:16

[@AllAmericanFiveRadio]

I forgot to label the volume control, it is 10K. That is high enough so it does not change the characteristics of the first stage output very much. A coupling capcitor between the first stage and the volume control would be good, about 10uF. Some amplifiers use mostly direct coupling between transistors, this is mostly in the power output section.

[@W1RMD]

@@AllAmericanFiveRadio I was going to ask about the potentiometer. Thanks for clarifying.

[@AllAmericanFiveRadio]

thank you, and your welcome.