I want to connect a graphic equalizer to my Onkyo TX-NR595 receiver. It has a zone B output but the audio inputs are all taken except for the phono input. That might be complicated. Any suggestions/help would be greatly appreciated.
You can only hook one channel of an EQ to the sub output of that AVR. Not a good idea as you could damage the sub if you boosted any frequencies. You could reduce the bass where it was excessive safely.
You can't hook up an EQ to that AVR for any other channels. There are no connections that will work.
An EQ could be connected to two channels of the AVR by using a speaker to line level converter and external power amp.