How to connect jacks from gemini stereo graphic equalizer eq2010 to harmon kardon avr40

I couldn't find the manual for this receiver, so you may have to adjust some of the terminology below to the labels used on the HK.

Be advised that the engagement of any device in a Tape Monitor loop will effectively tie the receiver down to stereo-only analog sound reproduction. I'll explain.

The connections themselves are fairly simple but it pays to understand what happens in the loop.

In general, any Line-Level external processor (EQ, dynamic range expander, etc) will go into a Tape Monitor loop on a receiver. A Tape Monitor, when engaged, sends the stereo analog signal Out to the Processor, massages it and returns it to the receiver via the Tape Monitor IN connectors to be passed on to the receiver's internal processes (volume, tone, whatever).

Old school analog stereo-only receivers consistently work this way. Newer digital and audio/video receivers introduce a couple of problems: 1) digital sound processing to simulate a variety of soundfields; 2) multiple output channels, either discrete or digitally-generated.

The latter requires that whatever signal is being processed experiences a maximum of one analog-digital-analog conversion.

EVERYTHING analog coming into the modern digital receiver is automatically converted to a digital signal for internal processing unless you choose a STEREO-only or STEREO-Direct setting. Consequently, no further external analog-digital conversions would be allowed if, say, a Tape Monitor circuit was activated, and a possible feedback loop could otherwise be created in a digital-sourced selection (output to its own input), so the unit is wired to treat the Tape Mon as the first analog step in the process and defeats any pure digital sources.

In a multichannel unit, what would happen to the other channels if you sent ONLY the Front Left & Right out for processing? That logical problem also plays into the decision to defeat digital sources if the Tape Mon is activated. I don't totally agree with the engineers but that's the way it is. Nature of the digital beast.

Okay, back to the hook-up: Receiver Tape- or VCR Out to the External Processor (EQ, whatever) Preamp-, Amp-, Tape- or Rec-In; Receiver Tape- or VCR In from the External Processor (EQ, whatever) Preamp-, Amp-, Tape- or Rec-Out.

If you actually want to use an analog recording deck you could place it within the typical Equalizer's own Tape Monitor loop(s). Many have two to facilitate equalized dubbing between decks.