which op amp would be suitable to amplify a 400mV peak signal ten times, i thought about using a transistor but it takes to long to get the transistor amp to work perfectly

 

What is the frequency range of the signal you need to boost?

hgmjr

 

You can probably use an LM358 or LM324 op-amp. There are several specs you are leaving out and therefore I can't help you more unless I know what you need. Like, is the input and output voltage DC and if so, are they both required to be positive? If your input is AC, can you tolerate an inversion in the output signal? What power supply voltage(s) do you have available or is this to be a battery operated unit? What bandwidth do you need? What gain accuracy do you need? Although it's not a complex problem, there is more to it than you might expect. It's always better to get these details out in the open before breadboarding. Also, I highly recommend that you simulate the circuit first to ensure that your output will give you what you expect. There is a great free spice simulator with no node limit and no time limit that's better than the ones they charge thousands of dollars for. It comes with a free schematic simulator and post prossesing graphic tool and has great documentation. Do a google search for LTSPICE or go to the Linear Tecchnology Corp website and put LTSPICE in for the search term.

 

its an ac input, i can tolerate phase shifts,the signal can lose its shape i am not going to use it again, after the the 10 gain amplifier i am going to rectify it to a dc voltage., well i don't have a restriction on supply voltages, the freq it should work anything from 0 Hz to 5kHz.

 

What are you planning to do with the derived DC from this circuit?

hgmjr

 

Feed it into a pic axe and store the dc value in a variable. So what op amp do you guys reccomen

 

I think not enough current to drive the PIC... Better use AC to DC converter..