I have 10 $55 Bitmain coupons which are expiring in 2 days (Nov 30th 2018). Don't need them so I'll send them to the first person who contacts me (privately).

Cheers!

EDIT: Coupons now expired. No takers - even for free. Lol.

[I TAKE NO RESPONSIBILITY FOR YOUR MINERS. USE AT YOUR OWN RISK.]

Update: So the firmware I posted earlier apparently has a hidden dev fee as pointed out by another user here. Have updated the title accordingly. Works fine though.

Original post:

I recently purchased firmware offering full voltage/frequency control and claiming to have no dev fee from ebay. Sharing it here for those who may be interested.

NOTE: I've used this for about a week now and see no issues on five of my S9's. I can't guarantee that there's no "hidden" dev fee but prima facie - there doesn't appear to be any.

I TAKE NO RESPONSIBILITY FOR YOUR MINERS. USE AT YOUR OWN RISK.

What I achieved:
1) Consistent reduction in voltage consumption by 15% or so. About 150w per miner give or take.
2) A marginal reduction in hash rate too. I was averaging about 14 TH/s per miner per day using standard bitmain firmware. With this firmware, though there is a reduction in power consumption, my hashrate is about 13.85 average over 7 days.
3) Note that my intention was NOT to overclock. I just wanted to reduce power consumption. OVERCLOCKING IS DANGEROUS. USES MORE THAN 1600W SO YOU'LL NEED MORE POWERFUL POWER SUPPLIES.

First download link from mega.nz - free account so download rate limited:
https://mega.nz/#!mbxSBCxR!gAcTMktLj94PoubgELS8nuqga84Lb1VnoYLVF9FuWjg

Second download link from Google drive:
https://drive.google.com/open?id=1gbEnUfsKisDEYsWosvVpH_sJt575zLcO

Some screenshots:
https://imgur.com/Mh3DEV0
https://imgur.com/evbDXSQ
https://imgur.com/wYP9t3z

Cheers!