Echo Rockit: Potentiometers behave strangely

Ruebezahl

Hiho!

A few months before i built the Echo-Rockit together with a friend (each of us one). It is all working great, except one thing: The Potentiometer, behave like they are logarythmical ones. One Example: The Oscillator starts with an almost subsonicly slow squarewave on the left. If i turn it more right it becomes a Basstone like maybe up to 150Hz and then in the last quarter it becomes almost immediatly a high beep. The same goes for all of the Controls like Cutoff, Resonance, the Delay Controls, all of them behave in a logarythmical manner.
The Pots we used i boughtfor 5cent a piece at taobao, this chinese website, and the information was just in chinese. so our theory was that we just bought 400 logarythmical Pots, instead of linear ones. well, shit happens Laughing

BUT: Today i was finally kicking my ass and replacing some of the potentiometers. I used pots from a source i was buying before a lot of times, and never had problems. To my horror, it turned out that they behave exactly the same. Now i really dont know what could be the problem.

Did anyone experience this problem before? Or has anyone an idea what could be wrong there?

Thanks a lot!