So to start off, let me quickly explain my setup which is in my Bar.
I'm using a Yamaha network receiver as my "Audio Switcher" with an output to a professional 70v amplifier which is connected to all my speakers throughout the Bar. I'm using this Yamaha receiver because I can connect to it via an Ipad and switch between various audio sources on the floor throughout the night without actually going into my AV closet.
My audio sources are 5 DirecTV boxes, Sirius Radio (integrated within the Yamaha Receiver) and a Chromecast Audio (used with the Spotify App on the ipad). My issue is that all these inputs have different line levels. Basically the integrated Sirius Radio is louder than my DirecTV boxes which is louder than my Chromecast Audio.
My current solution to this is to use a line level booster (see link below) on each input. My problem is that every time I add a new input, I have to buy and add another one of these line boosters. I'm planning on adding more inputs soon and I want to see if there is a better solution than buying more of these.
Basically what I'm asking for is something like the following device exists and what would it be called. One device that I can add at least up to 8 inputs, that each have their own individual outputs in which this device would have a knob (line booster) for each input. I'm not looking for a mixer because the Yamaha receiver is basically my mixer/switcher. I need one device that could replace all my line boosters for each of my inputs.