Celsius input buffer, bicolor led & dpdt as bypass

[Riccardo Turacchio]

Hi folks! Almost finished to build my Celsius, just waiting fo some caps and a metal can 2n2222A...so in the while I decided to check here on the forum for possible issues with this circuit and seems like a common problem is a treble drop when switched on high sensitivity mode
Many agreed that a solution would be a buffer before the input....
So my plan was to use a simple 3 X mixer before the preamp input and I was wondering if working with the right resistor values could be enough as buffer stage or would be better to use also a circuit like the simple jfet buffer or kliche buffer??

Here a schematic of the mixer

 

[Riccardo Turacchio]

I was reading somewhere that is possible to use a dpdt as bypass instead of a 3pdt
Cons....no more led for the status....in my case that wouldn't be a problem because what I'm building is more a "desktop version" than a stompbox...
On the other side I would be more interested to include a bicolor led that to goes from green to red when level is at max...
Suggestions ?