Mojotone P90 kit

[Bill Scheltema]

Hi guys,

I just got my P90 kit in and reviewed the parts.
I noticed that the A5 bars are magnetized, will they need to be remagged or will they be fine from factory, they seem weakish but that might just be me.

Bill

[Bill Scheltema]

cont....

Well just for fun here is the guiatr the P90 is going into, its headed to Norway.

Enjoy.

Bill Scheltema

[davos]

I always re-charge bars that come magnetised. I find it better to completely remove the charge first

[Rumblemeister]

Very nice. Please continue to post progress - I'd love to see how it comes out.

[tomatmojotone]

We precharge our magnets with a "Mojo built" high energy, capacitive discharge magnetizer.
They will be fully saturated when you receive the kit. That being said, there is nothing wrong
with experimenting with partial saturations and using rare earths to "hand" energize to various
levels.

[Bill Scheltema]

la Caliente update (formerly la Cabronita)

Hi guys and thanks for the responces.

I will be winding this pup real soon.
Here is where I am at right now.

[Bill Scheltema]

Oh I forgot one thing,

Is it customary to pot the P90's?

Bill

[copperheadroads]

They were not potted in the 50's
im not sure when gibson started potting p-90's but im guessing late 60's early 70's

[David Schwab]

They were not potted in the 50's
im not sure when gibson started potting p-90's but im guessing late 60's early 70's

I had a set of P-90s from the early 70s, and they weren't potted either. They came out of an SG. They had the clear bobbins.

[davos]

I also have a couple of 70s ones that weren't potted. They squeal like a pig fighting a baby! I always pot the ones I wind, you can get away with not doing it if you only play at bedroom levels but playing through a big rig live can make them uncontrollable.

[RedHouse]

Wind slower and be frugal with tension. Potting isn't always necessary unless you wind loose and/or at high speeds, then the baby-vs-pig thing applys.

[marku52]

Wind slower and be frugal with tension. Potting isn't always necessary unless you wind loose and/or at high speeds, then the baby-vs-pig thing applys.

Ok RH, I'm a little unclear here. "Frugal with tension". You mean too much tension can lead to microphonics? Or the opposite? I would think more tension would reduce microphonics, and it makes sense that slower winding would too.

[RedHouse]

Well I guees "frugal" is a lousy word here, sorry.

I meant more like be "on your game". When you wind fast (900-1400 RPM) it throws the wire out in an oval shape across the bobbin (which can be good, but) then, when you go to the tape-up stage you can tend to press the wire into the shape the bobbin actually is made, which makes for a loose coil, which will tend to microphonics.

Winding slower "lays" the wire on down, in nice tight (w/o excessive tension/stretch) layers, which after tape-up tends to help dampen itself from the tendancy toward microphonics. It's not yin/yang or black/white it's just a way of laying down turns so that potting isn't "always" necessary.

YMMV.

BTW, where is "SW Oegron"?

[big_teee]

Well I guees "frugal" is a lousy word here, sorry.

I meant more like be "on your game". When you wind fast (900-1400 RPM) it throws the wire out in an oval shape across the bobbin (which can be good, but) then, when you go to the tape-up stage you can tend to press the wire into the shape the bobbin actually is made, which makes for a loose coil, which will tend to microphonics.

Winding slower "lays" the wire on down, in nice tight (w/o excessive tension/stretch) layers, which after tape-up tends to help dampen itself from the tendancy toward microphonics. It's not yin/yang or black/white it's just a way of laying down turns so that potting isn't "always" necessary.

YMMV.

BTW, where is "SW Oegron"?

I agree with Brad!
If you keep everything tight and well taped, I like UnPotted P/Us.
Don't know if they would pass the Full Stack JCM800 Test or Not.
B_T

[Bill Scheltema]

Thanks guys, my instant email doesn't seem to work although it is checked off.

I will be winding the P90 real soon and have video too.

Bill