4001 treble pup Ohms details etc magnet

[Seans]

Hi,
i recently bought an early 72 4001 Jetglo, non wavy groovers, non skunk, walnut wings etc. But the bridge pup is very quiet, so I measure the ohms and it reads 12.5K ( should it be 6.5k ? or was this the norm? ), the cap has been removed and replaced by a wire, all this makes me think it should really be kicking out some volume . So looking at other 4001's from this period, they all seem to have very small magnets and perhaps mine just needs re magnetizing, which is what it needed when someone put some more coils on the pup?. The toaster is nice and full and measures 6.5K.

Any ideas, cheers, Sean.

[rickaddict]

Welcome, Sean.

I'm not an electrical whiz-bang, but there are quite a few on this forum who will probably be answering shortly.

But I have had a '72 4001 and a '71 4001 with the skinny magnet on the bridge pickup and both of them had lower output than my later 4001's.

Here's a photo of my Jan '71 wiring harness, if it helps:

http://www.rickresource.com/register/us ... llsize.jpg

Your reading seems a little high. I think my '71 bridge pickup is more like 6 or 7K.

I would think that with a hotter wound pickup and no bass-cut capacitor your 4001 would have good output.

[ken_j]

Early high gains have had issues with the magnet de-gaussing. Since you are getting a good resistance reading on the coil I would try adding another magnet or replacing the one that is there. I have seen this before but am not sure how common it is.

[heinpete]

Hi Sean,

that white wire of your bridge PU does not seem original. Did you check all circuit (with and without wire)?

[Seans]

Thanks guy's for the quick responses. Love that 71.
I have checked the ohmage with the pup removed, but only at the end of the white wire, not at the pup end. As the white wire seemed non original I had thought it may have been rewound, as I wasn't sure they made high output versions this early.

Need to look into this further, has anyone had good results re magnetizing these rubber magnets?.

[BAD RONBO, KiLLeR DWaRfS]

i see his .0047 cap missing/bypassed. he could also have a slight short to ground somewhere ? try wiring the pickup to an external jack and re-install the pickup top see if it is louder or the same. if it is the same volume i'd suspect the magnet. i had purchased rubber magnets from radio shack years ago that were like the current larger rick size. maybe rick could sell you a current regular sized magnet or cut one for you like the early slim mags.

[johnallg]

Trimming a new one wouldn't be too hard to do. Anyone with a magnet in the parts box??

[teeder]

If it was mine, I'd make it like a '73 size.

[BAD RONBO, KiLLeR DWaRfS]

well...as his coil has been fudged with , i think upgrading to the larger mag would be accepable...or he could find some real shoes to surround it !

[rickcrazy]

Hm... Indeed, something's wrong with that particular high-gain. I'd love to take a look at it, as something tells me it's been tampered with

[Seans]

When I get chance I will post some detailed pic's, minus the black tape etc.

[BAD RONBO, KiLLeR DWaRfS]

do not take the tape off !!! you may catch some windings in the adhesive and kill the coil if they snap. (unless you want to rewind it or unwind it back to original resistance.)

[johnallg]

Ron is right. The #44 wire is finer than hair.

[Seans]

Ok, so I'm hunting around for some NOS cap's, as this is missing for the pup, I find these and order them. In the mean time I find a very nice 73 pup sometimes these things just happen , no slot head pole pieces but still the ally base. I measure it and we're looking at 7.3K, as mentioned before it's got the bigger magnet and this is healthy, in we go and , now we're cooking on gas, it's got volume, punch and oodles of tone. Now to sort out the original pup, will keep you posted.

[johnallg]

Thanks for the update Sean. Love the 70s pickups! Let us know what you find with the original one too.