About a decade ago, I loaned an MFD pickup from my L2500 to a friend who had a legit pickup building business. The patents had been expired for some time and he wanted to reverse engineer the L2500 pickups and see about offering a replacement. Unfortunately, that project didn't get off the ground before things went off the rails and he had to close shop for personal reasons. I never did get that pickup back, but I bought a replacement from the G&L store and it's been in the bass for a long time now.
Anyway, there's no reason besides the initial investment in tooling and NRE that someone couldn't start building MFD pickups based on those original patents. But I don't see anyone else picking up that mantle, and I know that it's not an insignificant investment. I can't imaging getting that off the ground for less that $50k (maybe more) by the time you pay for NRE, tooling, equiment, inventory, etc. I don't see that kind of investment being easily recouped in a timely manner.
I'm sorry to hear your friend never returned your pick up but, glad to hear you were able to buy a replacement.
I contacted G&L a year or two ago saying I wanted to order several of their jazz pickups to put in other basses. They told me they don't sell them for use in other brands.
What equipment are you talking about?
Here's a pickup winding machine for $600
Build custom electric guitar pickups with the Mojotone Automatic Pickup Coil Winding Machine. Precision winding, digital controls & pro-level consistency.
www.mojotone.com
wire spool for $60. This'll make more than one set.
This is the highest quality pickup coil wire available. Perfect for repair and manufacturing. This is over 1/2 lb of vintage spec 42 ga. Heavy Formvar Min-Nom. This is the same type of wire that was most commonly used on vintage Fender pickups. 1/2 lb. will yield approximately seven single...
mojotone.com
Mojotone sells various other parts -- magnets, bobbins, etc, for $2-6 for the pieces I've seen. I admit that I haven't thoroughly put an order together. They also sell pickup kits for $12-34.
An authentic Mini Humbucker replica kit using the highest quality materials available. Sorry no substitutions for different parts. If you need something different than what is offered in this kit, we sell all of our pickup parts individually for your convenience. Included....(1) 50mm Nickel...
mojotone.com
So, to me, it looks like it's quite possible to get off the ground with a handful of pickups to sell for <$1,000. For most adults without children, or otherwise are several years into the industry they have a dayjob in; for those who can spend $1,000-5,000 on a single instrument, I'd say dropping a few hundred on parts to make pickups is a non-issue.
Granted, I have not yet sourced other specs for other DIY pickups. I'm sure there are companies out there willing to cut the metal into different sizes and magnetize what you want. I don't know what the minimum order would be. Considering Mojotone is selling pieces at markup for $6, unless the minimum order is 1k, this is not out of reach. I suspect 100 units would be likely.
Okay, 50 pairs of pickups in that scenario. Make a few one offs of any type as proof of concept to show legitimacy. Then start crowd funding and open preorders.
The expensive parts are networking, stocking gross amounts of inventory, storage space, paying
somebody else to build a website (DIY is cheap!), and most of all: advertising. Any established business has everything in place already.
What do you mean by "NRE" here? First thing that comes to me is something presumably unrelated to this. lol.
I think the only reason nobody else has started is that there isn't enough demand for it. I think most of us have been fairly loyal to G&L thus far. We simply seek out their instruments if we want that sound. Too few ask other companies to do it.
Didn't take me much time using DuckDuckGo web search to find a good list of G&L tech:
and specifically the MFD patent from the above:
https://www.freepatentsonline.com/4220069.pdf
Here's a video of DTT where he takes apart a wide MFD from an ASAT guitar. He talks about the magnet, materials, winding, sizes, etc.
Contrary to what I said above, people do ask him about this. I think I heard him say somewhere (not in this video) that if people want something like these, just to reach out and he'll do them custom. No idea what
his bass pickups are like.