A friend found this old Univox bass amp cheep, only it didn't work properly. I ripped it apart and found that the impedance selector was fried. I disconnected it and hard wired the 8 ohms tap and it sounds great. All it needs now is cleaning of the pots. http://schematicheaven.com/bargainbin/univox1050bass.pdf I found something interesting. The chassis isn't grounded!!!. All power grounds are run to the first filter cap which is floating. The controls are grounded to the input jacks. So the question is should I ground the power after putting in the 3 pronged plug or leave it floating?