What mags for a vintage soapbar P-90?

[belwar]

Hey Guys,

Im messing around with some P-09's right now and im wondering if anyone knows what mags would be used in the mid 50's soap bars. I do intend to experiment myself, but im just wondering if anyone has any recommendations of type and brands.

I plan to experiment with A2, A3, A4, A5, Iso A5, and Cobalt Steel.

Alot of people seem to like A5, but I dont recall reading that gibson used much of that in the mid fifties.

Any thoughts or comments on what I can expect from each? IS there any which should just be ruled out?

[voodoochild]

Hey Guys,

Im messing around with some P-09's right now and im wondering if anyone knows what mags would be used in the mid 50's soap bars. I do intend to experiment myself, but im just wondering if anyone has any recommendations of type and brands.

I plan to experiment with A2, A3, A4, A5, Iso A5, and Cobalt Steel.

Alot of people seem to like A5, but I dont recall reading that gibson used much of that in the mid fifties.

Any thoughts or comments on what I can expect from each? IS there any which should just be ruled out?

A3 Nails it IMO. A2 is too mushy and A5 is too sharp if you are comparing to original stuff. A3 has that beautiful upper mid range and growling lows that you hear distinctly in "good" vintage P-90's.

[belwar]

Wow, I didnt expect someone to say A3! I thought A2 was too mushy too. A5 was OK to my ear but I havent got that sweetness yet. I thought A4 "might" nail it, but now im curious about the A3!

[kevinT]

Spence would be a good resource for this question. I hope he chimes in.

[EFK]

I'm fairly positive Gibson used a good amount of A3 prior to maybe 1952-54. I've had early 50s p90s which I feel were definitely not A5 or A4.

[Possum]

...

they used the same magnets as PAFs which means they used anything they could buy for cheap....

[LtKojak]

they used the same magnets as PAFs which means they used anything they could buy for cheap....

If Gibson worked its "mojo" through getting everything for cheap, then today's p'ups coming from China would be the most "mojo filled" p'ups of all time!

Of course, people would know it only let's say, forty years from now?

[Spence]

The P90s that we all know and love were either A3 or A5. That early P90 of Jonson's is magnet steel cut from one double-length bar. Early examples of some soapbars had the fat DeArmond alnico magnets that were seemingly broken off to length. These also used a braided hookup with 4 strands per platt on the outer and an orange plastic insulated inner.
There's nothing to stop you using A2 or A4 in P90s. I have done both. A4s are quite good when used as a PAF substitute such as a P90-in-a-humbucker can.
Just think about the application when choosing a magnet.

[belwar]

spence et all.. thanks for the help so far. I guess that leaves me with a few question... how do we know they were A3? did someone have them analysed? or did that come off the wikipedia page? or does A3 just sound right. I was listening to make sound clips last night and there is something special about those early fifties p90s that I really like. I thin k I've got to set my recording rig up and do some objective tests.

[Spence]

Yes, they have been tested. I wouldn't rely on Wikipedia. There's no point in guessing these things when you can get them tested so easily these days.

[JGundry]

There is apparently no perfect method for testing Alnico. If you send a vintage magnet to a magnetics house they will fully saturate the magnet and do some sort of non destructive black magic testing that probably includes looking at the crystalline structure under a microscope and taking magnetic flux and a bunch of other readings. They are able to duplicate the magnet based upon these tests.

An x-ray spectrograph seems like a good way to test Alnico but apparently it has a wide enough tolerance that you can't really duplicate the mix of the original magnets from the results. On top of this Alnico is not a perfectly even distribution of metals. You have to take several sample readings from different parts of the magnet and then average out the result. In the end you get some interesting numbers but it is still an average reading with a fairly high tolerance.

You can do an inductance comparison with a pickup test bed. But the problem with this method is that it is purely comparative and each magnetics house will have their own tweak to any given Alnico mix so you can't really use it to compare magnets that are from different foundries without having a reference magnet from the source foundry to do the comparison.

I think there is a bit of a myth about Gibson using whatever magnets were cheapest. I know the names of 4 different magnetics companies that Gibson used and I'm sure there are probably more they used. Gibson probably shopped around for price. But apparently Gibson was not good about paying in a timely manner and they had supplies that over time refused to work with them because of it. But I think it is unlikely that Gibson called up a place and said give me the cheapest .125"x.50"x2.5" Alnico magnets you have. A magnetics company is a foundry. Everything is usually made to order and requires a drawing spelling out the size, tolerance, finish, Alnico to be used... If Gibson used Alnico 3 it would have been because they specified it in the order. But whatever Alnico was chosen would have been a little bit different mix from different magnetics companies and would sound a bit different even if it was the same grade. I talked to an engineer that worked for two different companies that used to supply Gibson and he confirmed that each place had their own version of Alnico 5, 2...

Given all of this the best thing to do is probably to find a vintage P-90 you like and pull the magnets and have them tested at a good magnetics house that makes magnets at the same facility that the test will be done at.

[Possum]

...

I've repeated this story many times, Jim at WCR talked to a retired magnet salesman who sold to Gibson during the classic PAF era, the salesman told him Gibson always bought their "reject" magnets for best price. What that actually means I don't know. Chipped or damaged, burnt, wouldn't hold a full charge, failed mix test, over or under spec dimensions? I don't know, but it is pretty clear that Gibson was cheap and saving a buck was as important to them as it was to Leo Fender. Magnets back then were the same they are now, meaning that each factory makes their own proprietary mix. Really what it boils down to is try every alnico you have access to and see what sounds best then use it. My current PAF set uses alnico 5 but I use 2 different manufacturers to best effect. Mix 'n match :-)

[voodoochild]

spence et all.. thanks for the help so far. I guess that leaves me with a few question... how do we know they were A3? did someone have them analysed? or did that come off the wikipedia page? or does A3 just sound right. I was listening to make sound clips last night and there is something special about those early fifties p90s that I really like. I thin k I've got to set my recording rig up and do some objective tests.

I don't know for sure it was A3 originally. All I know is that I have listened to plenty of vintage P-90's to know that today's A3 magnets match the sound you hear in the old ones perfectly. I mean the good old ones. I have heard plenty of vintage P-90's that sounded bad to me. You mentioned the word "sweetness" and that is what I associate with A3. Its always difficult to use the right word when describing a certain tone but "sweetness" says it. Thats the word.

[David Schwab]

I don't know for sure it was A3 originally. All I know is that I have listened to plenty of vintage P-90's to know that today's A3 magnets match the sound you hear in the old ones perfectly. I mean the good old ones. I have heard plenty of vintage P-90's that sounded bad to me. You mentioned the word "sweetness" and that is what I associate with A3. Its always difficult to use the right word when describing a certain tone but "sweetness" says it. Thats the word.

This made me think of my own P-90 experience. I once owned a Gibson ES-330TD, which is the fully hollow version of a 335. I think the scale length is different as well. I have no idea how old the guitar was. It had chrome dogear P-90s and a Bigsby. I'm pretty sure the guitar predated humbuckers.

The P-90's had a very sweet tone. The neck pickup in particular had that great hollow sweet tone like you would hear on a good Strat, only fuller and warmer.

While I owned that guitar I had someone give me a set of P-90s from an SG. He had me put humbuckers in the guitar. These P-90's sounded nothing like the ones in the 330. They had more mids and a harsher tone. They barked.

I have no idea what magnets they used, but I do know they were about 9K while the ones in the 330 were about 8K. So I unwound one of them down to 8K and stuck it at the neck in my Sekova LP Custom copy, and it sounded really nice. That same guitar had a patent label PAF in it. Hey, they were just used pickups! I didn't know much about pickups back then, and didn't even know there was different kids of alnico!

I'd bet the pickups in the 330 had different magnets than the SG's. The SG's were very likely A5s... they just sounded that way... more bite and all.

[Possum]

....

It might not have been A3. One fact you are overlooking is gauss levels. Alnico 5 put in a vintage P90 has both magnets repelling eachother, over 60 years they lose strength. When you have a P90 with low magnetic power they sound wonderful because you got a fat coil assembly with low magnetic drag on the strings so you can hear the fretboard and guitar's wood. MOst vintage magnets are alot softer/darker sounding than modern Chinese stuff so it wouldn't be hard to confuse A3 and A5 if dropped to similar gauss levels. Most old A5 is much smoother than the modern stuff is....