What is the deal with Mosrite pickups?

[tdbajus]

Novak makes a Mosrite for JM pickup. Wondering what the difference is between a Mosrite pu and a P90- anyone know?

[adamrobertt]

Pretty sure they're similar to P-90s - single coil, bar magnets, screw type pole pieces. The main differences are string spacing (Mosrites had super narrow necks) and they are very hot, like 10k or something like that.

[tdbajus]

I noticed the bar magnets are ribbed. Does mean anything?

[Jaguar018]

I noticed the bar magnets are ribbed. Does mean anything?

Yes. PLEASURE.

[tdbajus]

I served up that softball and it took three days for someone to swing at it?

[Embenny]

It should be noted that there was some evolution of the mosrite single coils over the decades they were made, but one important distinction I see from a P90 is that Mosrites seem to be wound with an "air coil" rather than around a bobbin:



This is not dissimilar to how Burns Trisonic were wound, although Trisonics notably had the magnet placed within the coil rather than underneath it like the Mosrite, so screw polepieces were unnecessary in Burns' case:



The proximity of the coil to the magnet/polepieces very strongly affects its behaviour. Look how much closer the coil gets to the polpieces on a P90 bobbin:



I think that this is likely the primary reason Mosrite pickups don't sound like P90s of equivalent resistance, even if wound with the same gauge wire and using similar magnets. The spatial relationship between coil, magnet, and polepieces is just plain different.

I don't know enough to tell you how this would affect inductance and those other properties that are important to a pickup's tone, though.

[tdbajus]

This is what I was hoping to see. Thanks.

[Jaguar018]

I served up that softball and it took three days for someone to swing at it?

I was busy over the weekend; if I had seen it sooner I would have made the the same obvious joke.

[Danley]

Had no clue about that pickup construction, seems like major feedback potential; am I wrong?

[Embenny]

Had no clue about that pickup construction, seems like major feedback potential; am I wrong?

From what I've read, most Mosrite pickups, at least of a certain era, were filled with or attached to the covers with epoxy, which would cut down on the feedback.

As for the Burns trisonics, they were notoriously feedback-prone, and Brian May filled his with something along the lines of epoxy early on (I'm sure the Red Special fans could tell you the exact product, it was something super British-sounding).

Edit: Found it. It was called Araldite, and it was indeed a two-part epoxy.

[windmill]

In case anyone is interested

The Ventures "Live in Japan 1965" album has been suggested as a good example of the sound of Mosrite pickups.

Here is an link to one of the tunes


The Ventures-Slaughter on 10th Ave

[hwestman]

My impression is that they sound thick and overwound based on what I have read and heard on YouTube videos.