The C1 hashing boards are S3 family boards.

So, yes - they are capable of changing the voltage.

I have a C1 Batch 1 and a C1 Batch 2.


The best settings for Under-volting/Under-clocking were suggested by another user:

0675/200      530W      803Ghs      0.66W/Ghs

0760/250      790W       1008Ghs       0.783W/Ghs

I set mine to 803GHs now because it's summer here and heat is an issue.
In the winter, 1008GHs.

Hope this helps