Microphonic pickups and pick tapping

scanfield

New member
Hi Everyone,
The humbucker pickup on one of my guitars has started squealing with high pitched feedback when used in high gain scenarios – very similar to this video: https://www.youtube.com/watch?v=Q5pAn055Ezs.

A search on the internet implies it is “microphonic”, and in fact, I can talk into my pickup and hear my voice come through the amp.

Coincidentally, I can also hear the tapping sounds through the amp if I tap the pickups or bridge with the pick, similar to this video (https://www.youtube.com/watch?v=rbMsOMqNYMY).

So I started checking all of my guitars – only one squeals like the first video, but for most of my other pickups I can hear the tapping similar to the second video. This includes several manufacturers’ pickups – both single coil and humbuckers, and active and passive. (Interestingly, my SD JB TB4 and Jazz SH2N didn’t transmit the tapping, but my SD Blackouts did.)

This makes me wonder if:

a) The second video is really a valid test of a “microphonic pickup”, and if so, is that a sign that my other pickups are degrading and will start squealing at some point in the near future?

Or

b) The second video is a bogus test.

If the second video is valid, then I wonder why my pickups are deteriorating. Is it something in my house (temperature/humidity changes, electronic field, WiFi signals, etc.) that is causing this?

Thanks.
 
Re: Microphonic pickups and pick tapping

Welcome to the forum.

In my opinion, the second video demonstration is an adequate demonstration of the mechanical noise transfer that can be expected from an unpotted covered pickup.

The obvious question here is, why are you tapping on your pickup covers in the first instance? :scratchch
 
Re: Microphonic pickups and pick tapping

Good question! Too much time on my hands? :onder:

Just trying to proactively see if I've got something strange which is negatively impacting my guitars (other than my playing, of course!) Several of the pickups which exhibit the tapping sound are advertised as wax potted, and some are only a couple of years old. Yet I still hear the tapping transmitted through the amp.
 
Re: Microphonic pickups and pick tapping

The coils of the open bobbin humbuckers in the second video are almost certainly wax potted. The critical thing is that the air gap between the bobbins and the metal cover is not filled with wax.

The usual description for this would be double wax potted.
 
Re: Microphonic pickups and pick tapping

Thanks. So it sounds like I'm worrying for nothing? Most of the pickups I tested have metal covers.
 
Re: Microphonic pickups and pick tapping

If you don't hear it during normal playing, I wouldn't worry about it. Add enough gain, and everything is microphonic at some point.
 
Re: Microphonic pickups and pick tapping

Luckily I don't go around tapping my pickups during normal playing... well, not intentionally! Considering my guitars are in the same room with my Wifi setup, plus an ethernet over powerline setup, I was worried that something might be making them degrade. I'll just turn it up and not worry! :headbang:
 
Re: Microphonic pickups and pick tapping

The critical thing is that the air gap between the bobbins and the metal cover is not filled with wax.

As in completely filled, or where the cover meets the top of the bobbins? I put a bit of wax in covers when putting them on, usually without any issue, but have noticed a hollow sound on at least one, so now wondering if I'm going about it the wrong way :-S
 
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