On Crypto Mining Blog Jabberwock (April 6th, 2014 at 00:46) http://cryptomining-blog.com/1839-another-new-voltmod-update-for-the-gridseed-5-chip-btcltc-asic-miners/#comment-842 measured 33k for R139 (what we call  R52 for easy reference). 

Thanks Zig, this might be exactly what I've been hoping for.  For me, I think it is easier to add a new axial resistor than to remove that tiny smd resistor. And, it could be easily re-bridged later if a SHA coin rises to and stays at the top of the profitability lists and you want to mine it.