the A-176 VC source module where I can apply fine tune to the a-110.
My Doepfer is an A-110 3-VCO system.

I'm using a chromatic tuner to tune my OSCs, but I just wonder what
pitch they should be tuned exactly to, is it A (440hz) or C. Or
should I just my ears to tune my osc.

I also want to add another 6U to my 12U I have just now. I want to add
a double A-155 sequencing unit. Can anyone tell me if this a good
choice of modules, or what modules I should need, thanks.

This is my choice:

Upper Row: A-155; A-156; A-150; A-151; A-160; A-161; A-142; B2-Blank

Lower Row: A-155; A-154; A-176; A-125; A-180; B2-Blank

G6 (2x84HP) Case.