Audio coming out of Input Jack and Filter is not working?

This is my first build so please bear with me and thanks in advance. I am getting no audio out of the “Output” jack, but am getting audio out of the “Input” jack?

Also, it seems that the filter is not working at all. All the voltages were correct during the power supply testing phase.
The jumper is on the “4 pole” selector as well.

Any ideas on where to start looking?


Have you inserted the chips in the right places/directions? Please Check!

The audio input is supposed to be… an input, so don’t be surprise if strange things happen is you do incorrect things.

Try probing the signal on those points (probe wire to the tip of a jack, other wire connected to the sleeve of a jack), and let us know at which stage the signal chain is broken.

I had this problem on my unit and it turned out I had inserted the LT1054 backwards because the chip had a dot rather than a half circle indent on it.

Like fcd72 recommends I’d check all the IC orientations first.

I did this too. Check all the chips are the right way round.


Everyone, thanks for the responses!
First I thought it best to just attach a photo of how I currently have all the chips inserted.
If someone could take a look and let me know if I have one seated incorrectly it would be greatly appreciated!

@pichenettes - if the chips are seated correctly, could you be more specific as to exactly how to probe the signal points again. Am I checking for continuity between points?

Thanks again!

Chips are inserted correctly.

No, you don’t need to check continuity between points. You need to “listen” to the signal coming from each point by connecting this signal to an amp.

Take an audio jack, attach a wire to the “sleeve”, and put this wire on a GND pad. Attach another wire to the “tip”, and use this to probe the circuit. I want to know what you hear at each of those points…

Ok, got it.

The only place I hear anything when I play a note is on point #1. I don’t hear anything when I play a note and make contact with any of the other points.

Any ideas where else to check?

Check all solder points around IC2.

Thank you for the great support, it is appreciated!
Got it figured out, I missed some solder points on IC2, but I’m sure you already knew that :wink:

It’s sounding great and I am getting ready to put it pin it’s case shortly.

Thanks again!

Nice bc3 congratulations and welcome to the shruthiversum

yay congrats!