Hi I have a Wollensak 4300 3M that plays cassettes well but cannot play audio over volume 2 on the volume knob. When I select a volume above 2, the device seems to base boost extremely loud. The device comes with an internal speaker which works but it is too quiet to hear well at level two. I plugged in a separate amplifier to demonstrate the problem further. I have disconnected the internal speaker. I am wondering what could be the root of this problem or if there is a way I can get to the root of the problem. I am still learning how to properly fix old technology so any information is appreciated. Thank you.