I would buy one multimeter ifI were you, a cheap insurance
But to answer your question;
I have had a really hard time to shade it down to 1.0 kOhm with a 4B pencil that is very soft, and that has given me 1.415 volts 3D.
I now bench @ 958/1250 no problems, this core scales like a dream
So if you go nuts on the shading I doubt you will get more than 1.45 volts out of it anyway, and that is pretty safe even on the stock coooler.
Bookmarks