Plugging Keyboards, phones etc. Into mic sockets.

[Bazz339]

Plugging Keyboards, phones etc into mic sockets that have phantom power on them.

 

Many of the cheaper desks only have global phantom power on the mic inputs, I am fully aware of DI boxes, balancing and other interface boxes and use them.

 

 

Yesterday someone plugged a keyboard into a phantom powered mic sockets using a MXLR to Jack lead (No idea of wiring) No damage to keyboard and did work but an interesting extreme oscillation when a brass band kicked off presumably caused by the induction loop that the keyboard was in the field of. Inserting a DI box got rid of that, however it set me wondering.

 

Has anyone ever damaged an item of equipment such as keyboard, phone, walkman by plugging it into a socket with phantom power on it?

 

I have always assumed damage to equipment was something that was theoretically possible and sought to avoid the situation.

[mackerr]

Plugging Keyboards, phones etc into mic sockets that have phantom power on them.

 

Many of the cheaper desks only have global phantom power on the mic inputs, I am fully aware of DI boxes, balancing and other interface boxes and use them.

 

 

Yesterday someone plugged a keyboard into a phantom powered mic sockets using a MXLR to Jack lead (No idea of wiring) No damage to keyboard and did work but an interesting extreme oscillation when a brass band kicked off presumably caused by the induction loop that the keyboard was in the field of. Inserting a DI box got rid of that, however it set me wondering.

 

Has anyone ever damaged an item of equipment such as keyboard, phone, walkman by plugging it into a socket with phantom power on it?

 

I have always assumed damage to equipment was something that was theoretically possible and sought to avoid the situation.

 

Yes. Blew up outputs 1 & 2 of my Roland Octacapture that way. Good thing it still has 6 jack outs...

 

Mac

[sunray]

Plugging Keyboards, phones etc into mic sockets that have phantom power on them.

 

Many of the cheaper desks only have global phantom power on the mic inputs, I am fully aware of DI boxes, balancing and other interface boxes and use them.

 

 

Yesterday someone plugged a keyboard into a phantom powered mic sockets using a MXLR to Jack lead (No idea of wiring) No damage to keyboard and did work but an interesting extreme oscillation when a brass band kicked off presumably caused by the induction loop that the keyboard was in the field of. Inserting a DI box got rid of that, however it set me wondering.

 

Has anyone ever damaged an item of equipment such as keyboard, phone, walkman by plugging it into a socket with phantom power on it?

 

I have always assumed damage to equipment was something that was theoretically possible and sought to avoid the situation.

Yes a brand spanking new HP laptop, purchased specifically for the event. It has been loaded with the software to play the files with, tested with headphones, taken to the venue for dress rehearsal - it worked into a 100W mixer amp with mono jack line level I/Ps. Next day full audio system installed & laptop plugged into mic I/P, playback stopped - forever.

Personally I like to add an isolating transformer for such devices, on almost every type of I/P. That also avoids noise introduced by SMPS chargers.

 

I purchased a 'B stock' Soundcraft SX mixer from a well known supplier, most of the O/Ps didn't - I always assumed something like this had happened to it.

Edited August 17, 2021 by sunray

[MarkPAman]

I killed a phone’s h/p output :(

[J Pearce]

I banned all XLRM to minijack leads at my last job for exactly this reason. 3 macs got their output fried before I started.

[Simon Lewis]

I banned all XLRM to minijack leads at my last job for exactly this reason. 3 macs got their output fried before I started.

 

A similar tale when I worked at a Uni.... It may have been embellished a little with the telling, but the story went that having failed to get music out of one Macbook using a 3.5mm to two XLR cable (with phantom accidentally applied) that the hapless user then plugged the cable into two more devices and fried those as well...

 

The XLR based cables were confiscated...!

[Bazz339]

So my caution was justified. I do seem to remember making up a mini jack to MXLR lead with some capacitors in the plugs for something. Not best practice but needs must sometimes.

[richardash1981]

I got burnt (fried output on an iRiver audio player) by factory reset.

The equipment was a ClearOne XAP800 matrix mixer, which has phantom-power capable microphone preamps on 8 of the inputs. The same connections also switch (software) to accept line inputs. I had long since switched phantom power off everywhere (as never used as microphone inputs) using the per-input software controls, and wired 3-pin phoenix blocks to various connectors, including a 3.5mm jack.

Then at some point I got the software configuration in a tangle, and pressed the factory reset button. It turns out that in the factory reset state, the first 8 inputs are in microphone mode and have phantom power enabled ...