Need to make a Mic/Line Level Mixer to solve Talkback issue while recording???

[Jasonmatthew911]

Hi guys, I've been needing a Talkback in my Studio setup for a few years now...I think in order to solve my problem, I need something similar to a Whirlwind PodMix (A Passive Mixer with Mic input, 1/4" TRS Stereo Line level input and both Mix to a TRS Stereo Output)...I need to mix a Microphone input for Talkback and the Headphone out of my old version Apollo Twin interface (That doesn't have the included talkback Mic) and summon the 2 sources to a 1/4" TRS Stereo Output that would then go into my Headphone Amplifier, rather than a balanced Mono output like on the Whirlwind PodMix, I'd like to stay stereo at the output if possible, and I'm hoping I can do this as a Simple Passive device...I'd also like to just add an SPST Momentary switch that makes Mic connection to talk only when pressed...Can anyone here guide me as to what schematic/circuit I need to wire up between my Momentary SPST Switch and XLR/1/4" jacks, or would just some 1K resistors between connections where they come together be enough?...This seems like a simple enough project if it's passive, but I'm not a 100% on how I should wire it up, or if the Mic won't need some kind of Pre-Amp circuit...Any help with this to do it right from the get go would be greatly appreciated, thanks.

[Jasonmatthew911]

Would this work as a simple passive talkback mixer or not that simple? (Check drawing)...I just need to insert a Mic into the headphone out signal of my interface...My interface doesn't have the built in talkback mic and I'm usually using all other inputs on my old version Apollo Twin, including the ADAT inputs when I'm recording Live drums, so all I can think of is that I need like a Mixer to Mix a Mic input into the output of my headphone signal which when then feed the 2 sources to my Headphone Amp...Please let me know if this is practical or not?...Wondering if this will work, or if my Mic signal would be too weak going into the headphone amp since it has no Pre-Amp?...

[PRR]

Your mike signal is too weak.

Your resistor network will spoil your stereo to about 12dB separation (I doubt that is critical if you use two poles so the two sides don't interact in non-TB mode).

I used to cut-up discarded $13 cassette recorders but I guess they are "collectable vintage" now.

[Jasonmatthew911]

Your mike signal is too weak.

Your resistor network will spoil your stereo to about 12dB separation (I doubt that is critical if you use two poles so the two sides don't interact in non-TB mode).

I used to cut-up discarded $13 cassette recorders but I guess they are "collectable vintage" now.

So basically, I need to add a simple Pre-Amp between Hot/Pin2 of XLR and SPST switch before going to the output?...And my resistor network should be ok wired this way or should I reconsider my connections and/or resistor values?...Please let me know if you recommend another way to do this...Thanks again for taking the time to reply.