Thank Jim !
I need a solution to :
1. input my studio mixer bus out (to send external synths to my modular).
I didn't see a vca in your rack - I would get a quad cascading one (also doubles as a mixer) that actually amplifies (most vcas do not) - mutable veils has always been my first choice and you may be able to find one new still, otherwise a used one, or an intellijel quad will do...
- lower the modular output to get into my studio mixer but in fact especially for headphones : stéréo out 1/4 jack (to not need any adaptor) TRS if available and a 'volume' knob.
have you tried just going straight from your eurorack mixer? is there clipping? if so attenuators or an output module will work - it'll probably be fine just going straight into your mixer with the appropriate cables - 1/8"->1/4" - I did this for a long time with a basic 15 year old 10 channel yamaha mixer
- send/return - send modular signal into a Beebo or an Organelle and returning with eurorack level. The Organelle output level is so low that i think it might be guitar level, perhaps so a 'gain in' knob can be very useful.
AISynthesis make an inexpensive pedal interface and you can get 2 in 4hp, if you need that... they are reasonably simple DIY builds - you'll need appropriate cables though (see above)
Don't know if it helps but here's my rack :
https://cdn.modulargrid.net/img/racks/modulargrid_1962355.jpg
please post an actual link (the url) to your public rack - jpgs are next to useless - and there are almost 10k modules - so the chances that I (or anyone else) looking at your rack ad not knowing at least one module is pretty high...
"some of the best base-level info to remember can be found in Jim's sigfile" @Lugia
Utility modules are the dull polish that makes the shiny modules actually shine!!!
sound sources < sound modifiers < modulation sources < utilities