This JBL UREI 6290 two - channel power amplifier is in working condition. Instead of regular knobs, it has caps installed.

To use this JBL UREI 6290 two - channel power amplifier, first connect it to a suitable power source. Make sure all your audio devices are properly plugged into the amplifier's input ports. You can then adjust the audio settings according to your needs. Although it has caps instead of knobs, it still functions well. When not in use, turn it off to save energy. Keep it in a dry and cool place to avoid damage. Periodically check the connections to ensure a stable audio output.