LM741 Op Amp

MrChips

Joined Oct 2, 2009
21,394
Well, sooner or later Audioguru is going to come by and tell you to scrap the ol' 44-year old 741 op amp and get something modern.
 

Wendy

Joined Mar 24, 2008
22,146
The fact is the old op amp has many uses, but audio is too fast for it. You could go with a TL074, which is 4 more modern op amps in a DIP package.

All the same op amp theories apply. The LM741 is an excellent teaching tool, but not the best part in the bin for general purpose work.

Are you wanting simple amplifier schematics? What kind of gain do you think you need?
 

bountyhunter

Joined Sep 7, 2009
2,512
Can anyone please let me where I can find simple schematics for a LM741 Stereo MP3 amplifier with great sound. Thank You.
There is no such thing as any type of audio amp using a 741 that has great sound.

I agree with the choice of TLO74/TLO84 for audio amps processing line level signals. LF356 is also decent.
 

Wendy

Joined Mar 24, 2008
22,146
I can draw up something if you want. I will not have tested it of course, but it is pretty basic. You are wanting to drive some headphones?

Audio Guru is pretty good with this stuff. Since you mentioned a 741 (which he hates with a passion) I expect he'll be around shortly.
 

Audioguru

Joined Dec 20, 2007
11,249
Since his teacher asked him to use a lousy old 741 opamp then I guess he will use it.

What will the opamp be used for? An MP3 player already has an excellent output.

Oh. This is his 3rd thread about an audio power amplifier.
First he asked about a low power LM386 power amplifier, then a TEA2025 amplifier that he could not make work.
 

Thread Starter

Bill Holben

Joined Feb 12, 2012
12
Ok everyone. Like I said before, let's start fresh. What are some of the modern, up to date amps that i can get. This is going to be a cell phone I will be using. I will be using two 6watt speakers. I am going to be using this on my bicycle so I want it to be loud with good sound. It will be powered by nine volts.Remember I am new at all this and I am learning as I go.
I appreciate everyones help. Please keep it coming.
 

debjit625

Joined Apr 17, 2010
790
Why don't you use an audio amplifier IC like TBA820 the simplest one I can think of.
Download the datasheet from STMicroelectronics,inside it you will find the circuit diagram.

Good Luck
 

Audioguru

Joined Dec 20, 2007
11,249
A little 9V battery can supply about 400mA for a few minutes. After about 10 minutes its voltage has dropped to only 7V and it is close to being dead.
Then its average power is 8V x 0.4A= 3.2W.

Most simple audio amplifiers produce heat in addition to output power so when the total power is 3.2W then the heating is 1.28W and the total sound power is only 1.92W.
Only 1W per channel from a stereo amp is not loud.

An ordinary audio amplifier like an LM386 produces only 0.45W into an 8 ohm speaker when the battery is 9V and its output power drops to 0.28W when the battery has dropped to 7V.

A TBA820 audio amplifier IC produces 1W in an 8 ohm speaker when a 9V battery is new and the power drops to about 0.64W when the battery has dropped to 7V. Its distortion is fairly high.
 

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Audioguru

Joined Dec 20, 2007
11,249
When I hear MP3 I tend to assume earphones. What I'm reading says speakers. So which is it?
In another thread he said he made a TEA2025 power amplifier that did not work.
In this thread he wants to use a 741 opamp as a power amplifier to drive his speakers, but it also will not work because it cannot drive a speaker.
He also wants to power this stereo power amplifier from a little 9V battery.
 
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