BOSS 4-Channel Stereo Mixer BX-4 I am selling this mixer as I am decluttering, after having stored it for about 30 years. I have tested its functionality prior to listing it. Power: It turned on using a 9V battery. Each channel input was confirmed, but there is some crackling. Panning and gain adjustment are possible. Stereo output is OK, but there is some crackling. Although there were no problems as far as I tested, since it is old equipment, I will consider it as junk. There are scratches, sticker residue, and dullness on the main unit. I have not tested it with an adapter. This is a personally stored item, so I cannot accept exchanges, returns, or refunds after purchase. Please be aware of this. The listing includes the main unit only. There are no accessories. #boss #roland #bx-4 #stereomixer