Author Topic: Shearching audio amplifier schematic  (Read 1711 times)

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Offline dbernotasTopic starter

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Shearching audio amplifier schematic
« on: January 06, 2021, 02:32:58 pm »
Hello

I have a problem and I am hoping someone could help me :)

I am looking audio amplifier schematic. I know there are tons of them on internet, and this is one of problem: I have no idea what to choose...
I will be building it my self, so it should be an easy one to make.

I will use it to power up 2x3wats (4 ohms) speakers and one 6w 6(ohms) "subwoofer". All speakers are from old 2.1 audio system used with my old pc.
I would like to make it stereo and it would be nice to regulate "bass" level separately.


 

Offline bob91343

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Re: Shearching audio amplifier schematic
« Reply #1 on: January 06, 2021, 08:27:17 pm »
It's a bit ambitious for a homebrew project.  You can find a unit that does what you need and look at the diagram.  But there are too many specifications for a simple answer.
 

Offline Le_Bassiste

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Re: Shearching audio amplifier schematic
« Reply #2 on: January 06, 2021, 09:04:44 pm »
Hello

I have a problem and I am hoping someone could help me :)

I am looking audio amplifier schematic. I know there are tons of them on internet, and this is one of problem: I have no idea what to choose...
I will be building it my self, so it should be an easy one to make.

I will use it to power up 2x3wats (4 ohms) speakers and one 6w 6(ohms) "subwoofer". All speakers are from old 2.1 audio system used with my old pc.
I would like to make it stereo and it would be nice to regulate "bass" level separately.

it really depends on how comfortable you are with designing (calculating)  and troubleshooting electronic circuits.
maybe, the lower powered (exactly the range you specified) integrated audio amplifiers are a good starter for you.
for example, TDA2003. super simple circuit and dead cheap.  a single one for each L and R, and another two in "bridged" configuration for the subwoofer should do for your purpose.
have a look: https://www.circuitbasics.com/complete-guide-to-build-a-10w-amplifier-with-the-tda2003/


« Last Edit: January 06, 2021, 09:06:52 pm by Le_Bassiste »
An assertion ending with a question mark is a brain fart.
 
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Offline Larryc001

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Re: Shearching audio amplifier schematic
« Reply #3 on: January 07, 2021, 06:08:02 am »
There are lots of kits for sale on the internet which have all parts and instructions for probably less than buying parts separately. Great for beginners. Here is one I particularly like because it looks kinda trick.

https://www.ebay.com/itm/Single-End-6J1-FU32-Tube-Amplifier-Kit-HiFi-3W-3W-Power-Amp-Audio-Amplifier-Kit/353344738491?hash=item5244fcd4bb:g:WNcAAOSwS3Ff9oBQ
 
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Offline andy3055

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Offline dbernotasTopic starter

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Re: Shearching audio amplifier schematic
« Reply #5 on: January 07, 2021, 08:44:55 am »
Thanx all for replaying.
I will be trying to do what Le_Bassiste suggested  :)

Seems interesting and not too complicated  8)

Will be updating on how its going :)
 

Offline dbernotasTopic starter

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Re: Shearching audio amplifier schematic
« Reply #6 on: March 26, 2021, 12:09:14 pm »
Hello again good people.

I am back. After some long trials and errors i made some progress :)

I took schematic from this site and made some changes
https://xtronic.org/circuit/amplifier/circuit-power-audio-amplifier-with-tda2030-2-1/


My approach looks like this
https://drive.google.com/file/d/1zsTLtkXBN6R8aFa591uhQWQGm2qU3U-l/view?usp=sharing

Difference is that I replaced TDA2030A amp circuit. I took it from datasheet.

And as for my power supply I didn't have transformer with center tap, so I found schematic how to make power rails.

And now i have some question:
  • Is it good to use such power supply without center tap transformer?
  • I use "pre AMP circuit" NE5532, but I don't understand why it is used, as I can hear my bass speaker is much more louder than left and right speaker. Maybe I could/should this kind of pre amp circuit on left and right channel ?
  • how to make effective low pass filter, because now my subwoofer sounds like big loudspeaker, I can hear great amount of mid range sounds?
  • Is it necessary/recommended to add electrolytic capacitor in series to speaker to save from dc voltage? What would be cons and pros ?

Thank you in advance.

 

Offline mariush

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Re: Shearching audio amplifier schematic
« Reply #7 on: March 26, 2021, 12:30:02 pm »
I'd suggest going up to TDA2050, as it allows you to go with as low as 9v (so you can power it from a 12v power supply, or a laptop adapter 16.5 .. 18.5v if you want to) and it's dead simple to use.

You can still buy clones from lcsc for under 50 cents each:

1. HGSEMI TDA2050TB : https://lcsc.com/product-detail/Audio-Power-OpAmps_HGSEMI-TDA2050TB_C434516.html

The datasheet also contains very clear schematic and explanations : https://www.st.com/resource/en/datasheet/cd00000131.pdf   (I've also attached it to this post)

The clones probably won't have same maximum power and will probably have smaller transistors inside so I probably wouldn't power them with near the maximum voltages,  but should still be good for 20-25 watts.

Here's a DYI project with it,  though they use the split power supply version, using a transformer to get negative and positive voltages : https://diyaudioprojects.com/Chip/DIY-TDA2050-Hi-Fi-Chip-Amplifier/

Keep in mind that these chips are only around 65-70% efficient, so you really need a heatsink on them if you give them lots of voltage and aim for high wattage.
 

Offline pqass

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Re: Shearching audio amplifier schematic
« Reply #8 on: March 27, 2021, 12:10:10 am »
In case you are not aware, a wonderful resource for all things audio can be found here: https://sound-au.com/
The project descriptions and articles are thorough.  A very good start for a beginner.
I'm not affiliated; just a happy user.
 


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