Designing a diode ladder filter from scratch

[analogoutput]

If you don’t have an oscilloscope, you can try using an audio probe as discussed here:

Need some help with the kosmo vco w/ tuner. Please! I’ve lost weeks

I think you should find out which parts of the circuit are working and which are not. And I agree with @analogoutput that you should concentrate on the analog side of the circuit first. One way of tracing AC signals, if you do not have any specialised equipment like an oscilloscope, is to use an audio amplifier. It basically boils down to that you probe the circuit and listen whether you can hear a signal where you would expect one. This should work with an oscillator as all it will produce (mo…

Starting from the signal input you can trace the path forward until you find where it (almost) disappears. That should give a clue what the problem is.

Main places to check would be outputs of op amps, + inputs where an audio signal should be, and before the input resistors on the - inputs where an audio signal should be.

Are you working from this schematic Designing a diode ladder filter from scratch - #17 by Dud or this one Designing a diode ladder filter from scratch - #34 by sharptrickster or something else?