My name is Lucas and I'm writing you from Chile. So ... Excuse my english.
Well, I would like to make a box that offers the option to give a mono out from a stereo signal at the input.
The stereo signal at the input comes from the last pedal of my set-up, an eventide time factor that sometimes i use in stereo.
To achieve this, i took the GGG simple guitar mixer circuit. With a 3PDT i would like to select betwen stereo (stereo in - stereo out, just routing) or mono out (Left in and Rignt In mixed).
The third row of the 3pdt will be used for led indicators: Mono or stereo.
Also, i would like to use this as a standar routing box. Sometimes I use the mono out of the eventide or other effect. For that, i added a switched input jack for the R-In. If the jack is unplugged, the right signal that goes into the mixer is muted (grounded). Then... the output will be only the L/mono input.
This goes like this, to match the "mono led".
The other way is seting the 3pdt to stereo mode (just routing) and then just use the L/mono-in and L/mono-out, but the "stereo led" will be on.
i'm planning to put thi on the breadboard probably the next week, but before that i would like to ask you for maybe some correctios or improvements to the proposed idea (Noise performance - Should add a Pf capacitor on the feedback loop of first op amp?, maybe use NE5532, What about impedances?)
Hope you can help me, here is the design.
Thanks in advance, best regards... happy new year!