OK. Pad before input transformer gives us "line" option.
Active buffer before input transformer for DI. When jack inserted, relay takes care of this.
Insert after micpre, right before the EQ will give us "only EQ" option.
Insert can be done with relay and active line receiver/driver....
This complicates a bit and requires +/- audio power supply instead of single + or - 24V
(depending on how old the Hel**s model is...)
Just a thought. Older Hel**s modules were using -24V supply. We need +24V for makeup stage (second half of BA283).
So, why not use +/-24V power supply and power from here switchable insert's balancing driver/receiver?
This way we have (if insert is "on") balanced micpre out and balanced input into EQ.
When insert is off, relay takes care of insert and sound does not passing thru balanced driver/receiver.
Carenhills can be easy sourced, but I will try to fit here standard RM10 inductors for folks
who want to save some money and wound inductors by themselves.
Regarding the Elma switch. The easy and cheap solution is next.
One Lorlin takes care of low cut, second takes care of low boost.
We can have even more settings with single 12-pos switches which is allways wellcome (more OPTIONZZ!!!!)
With use of dual on-on-on toggle, we can apply boost, cut, or both-oops, new feature!!!

For those who can't find on-on-on dual toggle, with use of dual on-on toggle (on same pcb) there will be boost or cut only option.
So, than, the thing will be not exactly original Hel**s, BUT this is what we want.
Ahemmmm....Thoughts?

? Oppinions?