Pioneer A-717 Sound Issue

Pioneer a-717 of this amp has low sound on one side. When the direct button is turned on, both sound the same. Then there is no tone control effect. Is the problem in the volume control? In the preamp? give advice
 

Attachments

  • schimb-pioneer-a-717-ii-amplificator-19kg-304254.jpg
    schimb-pioneer-a-717-ii-amplificator-19kg-304254.jpg
    88.3 KB · Views: 54