Review on 🔊 CT Sounds Universal Bass Knob - Digital Voltmeter, Blue LED Display, Remote Gain Control, Power Switch: Enhance Amp Performance with Durable ON/OFF Push Functionality by Brandon Pratt

I've read reviews that the voltmeter turns on when the amp is turned off and turns off when the amp is turned on. Now I'm just guessing, don't make it obvious when you press the button to turn the amps on when the display says 'off' and say 'on' when you turn them off? No ok, swap the blue and yellow wires and watch the magic happen before your eyes! Are you using RCA to send the signal to your amp? If so, it's VERSATILE and will work universally for you! Crazy true. NOW it works exactly as written and does a phenomenal job of doing it. I have 3 of these in my cars and no problems and I drive 140 a day so there is no problem with vibration. Please learn how to install or use a product before rating anything below 5 stars and that goes for any product. Just amazing Revain allows such ignorant incompetent negative reviews.