DIY Amplifier Modules

DIY STUFF
1

I do not want to clutter the Verified Stripboards space with my inexperienced questions, so am going to refer back to Verified Stripboard Layouts! - #215 by BlackDeath here. :slight_smile:
I’ve built this module, trying to replace an amplifier module I made when starting out (using a TL072 mixing module in the hopes that running signal through the OpAmp would make it louder).

This is all for the purpose of increasing the amplitude of my audio and CV signals so that my triangle and square waves sound close to the loudness of my saw waves, and so that effects such as filter cutoffs are manipulated on a bigger scale.

Unfortunately, neither of these modules make the signal any louder, meaning that it now just acts as a passive attenuator. Am I missing something? Would the pot I have placed after the circuit reduce the amplitude back down even if it is turned all the way up? Might I need to disconnect this from ground (left pin) to allow the signal to be louder?

Thank you all!

2

There are some good tutorials around on amplifier designs with op amps. The short answer is the gain depends on the ratios of the resistors connected to the op amp.

Here’s the circuitry I used in my 3340 VCO design to make all three waveforms the same amplitude and center them on zero:

image
image513×602 21.9 KB

The voltage dividers (R52, R54 and R53, R55) reduce the pulse and saw amplitudes to the same 0 to 4 V as the triangle, and then the op amps boost all three by a factor of 2.5 and subtract off 5 V.

3 Likes
3

Okay, I see. Thanks for this. So R54 and R52 divide the saw amplitude by a half as the resistance is the same in the resistors?
And then the pulse is reduced by roughly a third as well?

Also how could I implement this into my already existing circuit, just add resistors in the same format, 1 on the input directly and then another splitting off to ground?

Thank you!