I have an op-33 it stopped working, I contacted teenage engineering and they advised that it's because I was using rechargeable batteries. From what I remember I couldn't see anywhere in the instructions where its stated that I couldn't use them, again from what I remember I think I explained this to customer service.Either way, teenage engineering sent me out a new unit free of cost and told me I could keep the old one for spares.What more could you ask for?I can't remember the exact date this happened but it was a while back.
