Building an Audio Amplifier

[krips]

I'm currently working on building an Amplifier for a desktop speaker. I have created my circuit but need help analyzing the circuit. I am using a class AB amplifier and wanting to achieve a power of 5WRMS in my output using my phone as input signal. I am unsure of how to analyse the circuit and what values i need to achieve this. I have posted a picture of my circuit. If anyone can help me analyse or provide suggestions to improve that would be greatly appreciated.

 

[davenn]

hi krips

welcome to EP

I would be very surprised if you would get 5W from a 3904/3906 pair
why don't you use a IC amp like a TDA 2030 or similar would be so much easier

Dave

 

[ramussons]

The R6 connected to Q2 will result in a +ve feed back leading to Instability / Oscillations / Output DC latch up. R6 should go to base of Q1 and not Q2.

 

[BobK]

Like Dave said, the transistors you are using will not produce 1W, let alone 5W. You would need power darlingtons to output that much power.


Bob

 

[Colin Mitchell]

You can buy a 3w amp for $5.00 post free on ebay

 

[davenn]

You can buy a 3w amp for $5.00 post free on ebay

Colin, I'm getting really annoyed with your ongoing posts like this without providing links to the eBay page
If you continue to do this I will just delete your posts.
Now provide a link to this eBay reference !!

Dave

 

[Colin Mitchell]

Here's a stereo amp 3watt 3watt class D $1.00 post free !!!!!!!!!!!!!!!

http://www.ebay.com/itm/Terrific-Di...133?pt=LH_DefaultDomain_2&hash=item43d5123d1d

 

[davenn]

thankyou