Mylar 50's Bumble Bee Capacitors, Not Paper In Oil?????

[Mookakian]

depending on the value being exact i have to say the GE was a little more appealing, it may have been that the Bee wass a lower value but i hear some shrillness in the Mylar that is not present in the GE PIO, the mylar has an almost hi-fi tone in comparison. Thanks for the clips

[Luckynumber3]

Originally Posted by 5F6-A

it´s only normal that a thread about paper in oil caps becomes a "sticky"

Cool thread though. So, does this still mean that gibson's bumblebee caps are complete crap and nothing other than a dressed up cap, or do they have some sort of significance (even if they aren't PIO)? Obviously I would never spend $100 for Gibson Bumblebee reproductions, but if you have them in an r9 or other VOS, is their usefulness being sold short?

[cooljuk]

Originally Posted by Luckynumber3

Cool thread though. So, does this still mean that gibson's bumblebee caps are complete crap and nothing other than a dressed up cap, or do they have some sort of significance (even if they aren't PIO)? Obviously I would never spend $100 for Gibson Bumblebee reproductions, but if you have them in an r9 or other VOS, is their usefulness being sold short?

They are just Wesco polypropylene caps inside. I wouldn't call them complete crap. They function. Definitely not generally considered desirable tone caps among the guitar community, though, and absolutely NOT worth the price.

[cooljuk]

Has anyone else here made their own capacitor before? ...I mean from raw materials, not a special order from a rolling house.

[jonesy]

Originally Posted by Luckynumber3

Cool thread though. So, does this still mean that gibson's bumblebee caps are complete crap and nothing other than a dressed up cap, or do they have some sort of significance (even if they aren't PIO)? Obviously I would never spend $100 for Gibson Bumblebee reproductions, but if you have them in an r9 or other VOS, is their usefulness being sold short?

This same subject came up in back in 2005, here is Gibsons reply ...more pics, and data sheet about the Wescap Poly film capacitor at the link below.

Edwin Wilson's Bumblebee Capacitors




Edwin Wilson on reissue Bumble Bees

Regarding a letter from Edwin Wilson the program manager of the Custom, Art & Historic Division at Gibson
which was posted at Gibson Guitar: Electric, Acoustic and Bass Guitars, Baldwin Pianos in late 2004.
While this letter is long-gone from Gibson's website, it is saved here with some additional information from
the Les Paul Forum and Wesco, the company that manufactures the reissued capacitors.





I am writing this in response to some concerns on both the UNOFFICIAL LES PAUL FORUM and the Gibson Custom Shop Forum about our Bumble Bee capacitors and their authenticity, construction, specifications and the approach to reissuing any hardware on Gibson Historic Products.

First of all, to all those that are experts regarding capacitors just work through the first part of this with me because there are so many people that I have heard toss around descriptions like ceramic, oil filled, foil, mylar,teflon, and paper I feel a little general information is necessary to clarify. The actual definition of a capacitor is: An electronic circuit element used to store charge temporarily, consisting in general of two metallic plates separated by a dielectric. One of the main differences between the various styles of capacitors is the dielectric medium used. In a ceramic capacitor the dielectric is ceramic. The parts used in this style of capacitor consist of the metal plates which have the solder leads attached to them and the dielectric which is ceramic. This is also the most inexpensive capacitor available with the poorest ability to hold a charge. The next one is a mylar capacitor. With this one, it also consists of two metal plates which are the points that you solder and the dielectric which in this case is mylar. The capacitor with the highest quality material and performance is a teflon capacitor.


Reissue bumblebee leads
Typically this style is used in higher end custom audio applications where exacting tolerances are necessary. If you go back to the days of antique radios, you will notice some of the first capacitors were oil filled capacitors. With this style capacitor it consists of two conductors which are the metal plates and the dielectric material which is oil. Typically these parts had a metal can around them so that the oil would be contained. There were many materials used as the dielectric material including paper and foil. As many of you know also on any old electronic part the variations in different tolerances were much greater than now. What was considered a high quality part in the 40's and 50's was a variation of +/- 20%. By today's standard that is totally unacceptable. Once again the bottom line is the metal plates generate a charge when a signal is sent into them and the dielectric material holds the charge and releases it on a constant. So with all of that said let me get into how this project was approached.

So many times when I R & D parts or models for reissues I get assistance both positively and negatively from many sources and all input is appreciated. But in addition to this input I also have access to a vast amount of engineering documents,blueprints, and purchasing records dating back to the '40s, '50s, '60s etc. So many times when it appears that someone at Gibson has not reissued a part or a guitar to a particular individual's idea of what it should be, the closest most realistic information from a manufacturing standpoint is the documentation that we used to make the parts/guitars originally (even though sometimes there are variations between what the blueprint says and what the part ends up looking like).


Reissue BumbleBee foil


When I started this project I contacted Sprague (the original manufacturer of Bumble bee capacitors), and got as much information from them as I could. Next I went to our purchasing records and searched until I found the vendors that were the distributors and actually sold Gibson the parts. On these documents I found not only the vendors names but also the exact description of the parts and the specifications. Next I went to see if there were any blueprints but I did not have much luck there. Oh one other thing I forgot to mention one of the things I keep in my possession here at the Custom Shop are many original pickup, control assembly, and pickguard sample parts from as far back as the 40's including an original Double 12 wiring harness dated on March 1958 on the inventory/tracking tag.

So once I found a vendor* willing to listen to my request I sent him 5 original Bumblebee capacitors to run tests on with the specifications from my purchasing records. Once he ran the tests he informed me that to a degree there was a varied range of the voltage and capacitance. Two of the capacitors read exceptionally high indicating some kind of breakdown within the dielectric material (foil).
*WESCO

Three of the capacitors were right on with what I had found in our records and with what the capacitor was supposed to be spec wise according to the color bands on both the original and the new. It was very easy to see but we still ran the test to make sure the color bands were actually what the part was. For those of you who do not know how to read the color bands on a capacitor, (it is different than a resistor), I have attached a sheet explaining. Next I discussed the actual construction, material and dimensions. I wanted the wire size on the leads, shape, color bands, tooling marks,color and all to be as close as possible but most importantly it had to be a foil capacitor with a dielectric at least comparable to the original brown craft paper and the specifications had to match the original bumble bees. On the reissue bumble bees the dielectric material we ended up going with was a poly film that exhibited the same properties as the craft paper did. This decision was made based on numbers and manufacturing issues. It is simple math, if one material conducts at a certain rate then if you find another comparable material and make the necessary adjustments be it in size, thickness, or turns the you end up with the same desired result. On the first samples they sent me they were plain without the shell just the foil and leads showing so that I could approve the construction. Next came the outside shell with the color bands and tool marks. Finally came the finished part.


Original bumblebee foil

I did not take these and x-ray them but as with all good R&D'd projects, there are sacrifices. So attached I have put some of the tech sheets from my vendor for you to read over, along with some detailed pictures and my measurements I took of an original bumble bee I took apart and some other ones of a recent new reissue bumble bee's so that everyone is very clear that this is not a ceramic capacitor in a nice package but truly a foil capacitor, like the original bumble bees, in an injection molded case, like the original bumble bees.

Earlier on in this I said I appreciate all input and I do; it helps all of us at Gibson make better decisions about the product. But I still find it amazing that some people still think that someone is out to get them. I remember '80s Les Pauls that were not even the right shape, had the wrong necks, peghead shapes, routes, made from African Mahogany not even the same species, wrong binding size, wrong hardware and at that time this is what the company offered as a reissue style guitar! Yet now in 2003 when we go through the greatest lengths to make the guitars correct, when we use the highest quality materials ever in the company's history, the body shapes, necks, pegheads, neck tenons, pickups, pots, capacitors, and aluminum stopbars are more accurate and close to an original that ever, there are still individuals that feel we are out to pull one over on them. The things I mentioned above are the most important elements in any guitars sound and playability, except for one thing I left out..... the guy playing it.


Original BumbleBee leads


Our intent with the bumble bee capacitor was to make a reissue capacitor as authentic as possible using the same basic elements that the original ones used, with the same specifications and performance, to make a part that in 20 or 30 years was still going to perform as well then as it did new, to improve the quality of sound of the guitars and be another contributing factor in making these guitars one step closer in sound and playability to an original, And the greatest guitars that anyone could ever own. And we feel very strongly as do many others that we have accomplished this. If there are any further questions about this or any other parts/guitar issues, before any wrong assumptions are made, please feel free to get in contact with me directly at ewilson@gibson.com, or use the Historic Program Discussion Forum found at Gibson Guitar: Electric, Acoustic and Bass Guitars, Baldwin Pianos.

[Luckynumber3]

Cool, so they are pretty good then- I still wouldn't pay $100 for them.

You are the person who deals with caps- have you ever got your hands on the bees and saw if they sounded any better than the average cheapo cap in usa gibsons?

[jonesy]

Originally Posted by Luckynumber3

Cool, so they are pretty good then- I still wouldn't pay $100 for them.

You are the person who deals with caps- have you ever got your hands on the bees and saw if they sounded any better than the average cheapo cap in usa gibsons?

All I can say is that I have provided dozens of 50's style LP harnesses with new old stock .022 paper in oil caps to players that have taken these Wescap Bees and stock pots out of their Historic LP's because they found them to be harsh and un-appealing. As a vendor if I say anymore my post will probably get deleted.

[5F6-A]

Originally Posted by Mookakian

depending on the value being exact i have to say the GE was a little more appealing, it may have been that the Bee wass a lower value but i hear some shrillness in the Mylar that is not present in the GE PIO, the mylar has an almost hi-fi tone in comparison. Thanks for the clips

no probs.... this is what I have had until recently in my LP



although very nice looking and sounding caps I have swapped them for General Instruments... (can´t find the camera to share a pic with you lot) the GI PIOs just sound a bit creamier. Very nice indeed...

[tazzboy]

Originally Posted by cooljuk

Has anyone else here made their own capacitor before? ...I mean from raw materials, not a special order from a rolling house.

Yeah I am Curious about that.

[jonesy]

Originally Posted by cooljuk

Has anyone else here made their own capacitor before? ...I mean from raw materials, not a special order from a rolling house.

Yeah I made some a few years ago with tin foil and plastic wrap, they were about the size of a short cigar when I was done and it was hard to keep the oil from running out when you don't have a metal case and sealed ends.

[cooljuk]

Originally Posted by jonesy

Yeah I made some a few years ago with tin foil and plastic wrap, they were about the size of a short cigar when I was done and it was hard to keep the oil from running out when you don't have a metal case and sealed ends.

Nice, man.

It doesn't take much to make a cap. It definitely takes a great deal of skill and tooling to make a reliable one though. Much less, more than one or one that is a reasonable size.

I played around with Leyden jar types when I was younger and only recently became interested in building PIO caps.

[lorenzo]

Great post, jonesy! Thanks!

[jonesy]

Originally Posted by lorenzo

Great post, jonesy! Thanks!

Thanks, glad you liked it and you're welcome

[jonesy]

Originally Posted by cooljuk

Nice, man.

It doesn't take much to make a cap. It definitely takes a great deal of skill and tooling to make a reliable one though. Much less, more than one or one that is a reasonable size.

I played around with Leyden jar types when I was younger and only recently became interested in building PIO caps.

Yeah the theory behind a capacitor is pretty simple, making them is a different story. And I agree it's hard to get them into a small compact case. If you do make some caps post a thread I would be interested to see how they turn out and how they sound

[Mouse]

Originally Posted by Mookakian

Even after a soapy wash that sticky gunk has left an oily film on my fingers, i reckon id be a bit quicker on the fretboard!...but dinners cooking, best get out the lighter fluid

haha I know the feel, you should hear balalaikas in your head after few days

[tazzboy]

Yeah I like to see how it's done as well.

[5F6-A]

the theory behind capcacitors is not hard to grasp but actually building them at home as if we were baking biscuits with the kids on rainy Saturday evening is a different issue. Still, most of the caps out there are good and fishing for the right one for your guitar and style is a very rewarding experience.

[David Collins]

Okay, here's an old PIO Bee that I took apart. A bigger one, .220μf / ±20% / 400v it appears, already cracked when I found it.



The curious point I hadn't given much thought to before was how they were assembled. For some reason I just assumed that the plastic was molded around the foil wrap, but as said, I hadn't thought much about the manufacturing process before. It seems from looking at this one that the housing may have been molded in two halves, then pressed and joined around the foil roll.



Here you can see how the rolled foil seems pressed in to the irregular shape of the molded housing.



Unrolling it there were several wraps of paper beyond the foil -



Completely unwrapped, this measured roughly 5' of foil, 1_5/16" overlap.



With the foil extended on opposite ends and mashed over to meet the leads, it seems traditional "Extended Foil" production.



For whatever it's worth, just though I'd add these pics in to the mix.

[jonesy]

Nice pics David, looks like that Bee had an oil filler tube on one end. Did you notice any oil left inside when you unrolled the foil or was it dry?

[David Collins]

No loose oil, but the paper was certainly still saturated. I have a few more I got with a box-o-caps which are still intact that I may break apart. I won't be back in the shop until at least Saturday, so maybe I'll crack another open this weekend.



The ones on the right are PIO, Mylars on the left. And I got a big nasty old ball of wax to play around with as well -

[David Collins]

And speaking of what's commonly referred to as the "oil filler tube", this got me wondering about that as well. From a manufacturing perspective, if the foil/paper were actually rolled dry and filled later, it seems to me that even if you were to put the cap under full vacuum, it would be awfully difficult (if not impossible) to fully saturate the paper after assembly.

If my assertion that the housing were pressed together from pre-molded halves around the rolled foil is correct (still not sure about that), then it seems more likely that the tube would have functioned as a pressure release as the casing was joined by heat, or perhaps shrunk as it hardened?

Dunno. It seems like saturating paper wound tightly with foil, with crushed ends, and only one tube in with no escape vent would make filling the cap with oil after assembly near impossible. Maybe it actually functioned as pressure release tube during construction?

[martin6string]

Originally Posted by David Collins

And speaking of what's commonly referred to as the "oil filler tube", this got me wondering about that as well. From a manufacturing perspective, if the foil/paper were actually rolled dry and filled later, it seems to me that even if you were to put the cap under full vacuum, it would be awfully difficult (if not impossible) to fully saturate the paper after assembly.

If my assertion that the housing were pressed together from pre-molded halves around the rolled foil is correct (still not sure about that), then it seems more likely that the tube would have functioned as a pressure release as the casing was joined by heat, or perhaps shrunk as it hardened?

Dunno. It seems like saturating paper wound tightly with foil, with crushed ends, and only one tube in with no escape vent would make filling the cap with oil after assembly near impossible. Maybe it actually functioned as pressure release tube during construction?

Excellent post. It's certainly a plausible theory.

There is definitely some mystic behind the original Bee's, whether they are PIO or Mylar, regardless if they are the flavor of the week cap.

I have them installed in a few of my Historic's and there is just something different about them that steps above the rest of what I've tried.

[jonesy]

Originally Posted by David Collins

And speaking of what's commonly referred to as the "oil filler tube", this got me wondering about that as well. From a manufacturing perspective, if the foil/paper were actually rolled dry and filled later, it seems to me that even if you were to put the cap under full vacuum, it would be awfully difficult (if not impossible) to fully saturate the paper after assembly.

If my assertion that the housing were pressed together from pre-molded halves around the rolled foil is correct (still not sure about that), then it seems more likely that the tube would have functioned as a pressure release as the casing was joined by heat, or perhaps shrunk as it hardened?

Dunno. It seems like saturating paper wound tightly with foil, with crushed ends, and only one tube in with no escape vent would make filling the cap with oil after assembly near impossible. Maybe it actually functioned as pressure release tube during construction?

The oil may have been put into the paper and foil right before the case was molded on and the outer layer of paper kept it in? It would be really interesting to see how that whole manufacturing process was done at Sprague back in the 50's.

[Mookakian]

Originally Posted by David Collins

And speaking of what's commonly referred to as the "oil filler tube", this got me wondering about that as well. From a manufacturing perspective, if the foil/paper were actually rolled dry and filled later, it seems to me that even if you were to put the cap under full vacuum, it would be awfully difficult (if not impossible) to fully saturate the paper after assembly.

Maybe they heated the oil to thin it and increase the absorption process, pump a little oil in and then let it sit in a temp controlled environment to soak in

Maybe a few sprague workers also worked in area 51 and slipped out a few of the ET's secret starship components, so the BEE was limited stock

[guitar_slinger8]

jonesy your doing an awesome thing with this thread!!!

[jonesy]

Originally Posted by guitar_slinger8

jonesy your doing an awesome thing with this thread!!!

Thanks bro!

[jonesy]

I dug out mt stash of Original Sprague Bumble Bee Capacitors from the late 50's and took some fresh pics and meter readings. As you can see many of these old Bees drift way beyond their original specs. This is one reason I have gotten away from trying to source them. You can also see the solder blob/filler tube on the ends of these that indicate paper in oil construction.

I also noticed on the .010 Mylar film Bees the case molding is slightly different on one end compared to the PIO .010 Just for comparison I metered an .022 Sprague Vitamin Q and .022 HYREL and after 40-50 years they still read right within original specs. More pics of these Bees in my jonesyblues Photobucket account...Bumble Bee Capacitors Sprague Original 1950s pictures by jonesyblues - Photobucket

[jonesy]

New Old Stock PIO 10% tol. .047 Bee reading .072

[5F6-A]

great info Jonesy...

Mylar bees seem to fare better than PIO bees in the "drifting" department, don´t they?

[jonesy]

Originally Posted by 5F6-A

great info Jonesy...

Mylar bees seem to fare better than PIO bees in the "drifting" department, don´t they?

Thanks!



No not really Hilario, I have quite a few Mylar .010 Bees that actually now read .033 or greater so that's 3 x darker than original specs.