LM3915/LM741 amplifier

Thread Starter

AR_BO1021

Joined Nov 28, 2015
4
Hi

I have built a vu meter with the LM3915 IC and i want to amplify my audio signal because its to low from my mp3 which is 300mV.
To how much should i amplify the voltage and why?
Is lm741 a good amplifier to use?
Is there any difference between using ±12v or 0v and 24v to supply the lm741 amplifier?

Thanks,
 

Lestraveled

Joined May 19, 2014
1,943
Hi
First, what did you set the reference voltage to? Now is a good time to post a schematic.
 

dl324

Joined Mar 30, 2015
8,860
Is lm741 a good amplifier to use?
Probably not a good choice for your application.
Is there any difference between using ±12v or 0v and 24v to supply the lm741 amplifier?
Yes. LM741 is spec'ed to have a common mode input range to about 3V from the rails. If you use a single supply, the input couldn't go below around 3V. With dual supplies, oV would be supported. If you don't already have a negative supply, I'd use something else.

As mentioned, you should post a schematic so we don't have to guess about your circuit.
 

benta

Joined Dec 7, 2015
101
1: no need to amplify anything, just insert a voltage divider between REF-OUT and R-HI.
2: The LM741 is NOT a good amp to use in ANY situation. Send it to its grave and RIP.
3: not relevant.

Benta.
 

dl324

Joined Mar 30, 2015
8,860
2: The LM741 is NOT a good amp to use in ANY situation. Send it to its grave and RIP.
It will work fine for many applications. I have dozens in my parts bins and find them still quite useful.
 
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