Obsidius Only Squeal

[horrorfan]

Hello,

I finished the Obsidius build and I am only getting a high pitched squeal.
The noise is not related to how loud the bass is played and is present if any amount (above zero) of level or blend is used together. It is not tied to the amount of drive.
In fact if the squeal is there.... there is no effect audible.
I have swapped the TL072’s with no remedy.
However if I leave out the TL072 that is on the right side , the squeal is gone and the controls work. The effect and drive are just weak.
If I place a brand new IC in that socket the squeal resumes again.

Any ideas?

Sorry .... I tried to describe that as best as I could.

 

[PapaBear]

Can you post pictures?

 

[Robert]

The noise is not related to how loud the bass is played and is present if any amount (above zero) of level or blend is used together.

Just to clarify...
If you turn both Level and Blend all the way down, then turn up one or the other (not both) does it squeal? Or do you have to turn up both?

 

[horrorfan]

Just to clarify...
If you turn both Level and Blend all the way down, then turn up one or the other (not both) does it squeal? Or do you have to turn up both?

The squeal is only when turning up both level and blend.
Level 1% to 100%, Blend 0%= no squeal
Level 0%, blend 1% to 100%= no squeal
Level 1% to 100% AND blend 1% to 100%= squeal and no effect to bass signal.

Remove the one TL072, no squeal, weak effect but it present and controllable.