I have heard a sound like a creaking metal heater warming up, but holding it near my head I also hear a constant even little ticking sound that I believe indicates a PWM approach to temperature control. Turning the temp down did seem to slow the pulses, so I’m pretty sure that’s what’s going on.
Glad to hear it was just battery issues for you too
@Tombudster ! I should also give an update about my own battery issues.
I managed to try a Molicel P26A again, and I realized what screwed me up before. As any of these batteries drain they provide less power at once, so it heats slower (and vibrates less strongly). The P26A at full charge seems to provide more at once than the VTC6 and also maintains that super fast heating longer, but they do both drop off.
I was failing to sufficiently adjust my pre-heat time and draw speed/length as the batteries drained, especially with the VTC6.
I would still consider the P26A better than the VTC6 here (both were new) so I still want to figure out how to use the Molicels without worrying I won’t be able to get them out again, but I am also getting good results with the VTC6s now.