I kept reading about the impedance switch...and I thought "WHERE is this thing?!"
Well, I finally found it. I take it that I remove the plastic piece and replace it where I want it? For low, or high? It's set to medium.
I need to pick up some Deoxit eventually. That stuff is expensive, man!
You don't need a lot of the Deoxit, the 7.4ml bottle has lasted me about 2 years and there is still about half left, don't get the spray, the brush works better and get good lint free cleaning cloths like a microfiber or the ones they used to clean tape heads or transport rollers.
When changing the impedance switch remember to set both to the same setting and you can do this while the amp is in use so you can hear the changes quickly.