I were checking continuity of a headphone cable looking for shorts between pins and in a crazy moment I had the “amazing” idea of checking continuity looking for shorts with the cable connected to the headphones. It was a very brief testing and I began to hear some popping noises and suddenly I understood I was sending DC to the headphones coils. The headphones are very expensive ones (HD800S 300ohm). I tried them after and they seems ok but I’m very worried if I had damaged the drivers or affected to their performance or characteristics in some not so evident way (they are carefully matched drivers).
Any comments will be very welcomed!
Any comments will be very welcomed!
i reckon the chance of damage is very small indeed because the current involved when using a multimeter for continuity is of the order of a milliamp. Whereas the AC currents into headphones when playing audio are in the region of tens of milliamps.
A sharp probe point going through the driver seems to me the quickest and easiest way to damage one using a multimeter.
A sharp probe point going through the driver seems to me the quickest and easiest way to damage one using a multimeter.
Thanks for your comments!!��
I have measured the voltage used by my multimeter when chwcking continuity and its 1.015V and 0.320mA.
So, what do you think?
Thank you so much and happy (and healthy) new year to everybody! ��
I have measured the voltage used by my multimeter when chwcking continuity and its 1.015V and 0.320mA.
So, what do you think?
Thank you so much and happy (and healthy) new year to everybody! ��
1 V is well below the max rating of the Sennheiser headphones. If I recall correctly, they're rated for 200 mW, which is nearly 11 V, peak, into 300 Ω.
Getting 320 mA to flow in 300 Ω would require 96 V, so the meter will be limited by the amount of voltage it can produce in the continuity test.
In summary: Don't worry about it. It's probably not a good idea to leave the meter connected to the headphones for days on end, but for a brief measurement I highly doubt you did any damage.
Tom
Getting 320 mA to flow in 300 Ω would require 96 V, so the meter will be limited by the amount of voltage it can produce in the continuity test.
In summary: Don't worry about it. It's probably not a good idea to leave the meter connected to the headphones for days on end, but for a brief measurement I highly doubt you did any damage.
Tom
Thanks Tom! Your comments really give me peace of mind. By the way I measured 320uA (0.320mA) so I suppose it’s better.
Thanks!!!������
Thanks!!!������
Ah. 320 uA. My bad. Thats 31 uW. Nothing to worry about, but enough to make some scratchy noises in the headphones.
Tom
Tom