L-100 fund raiser project

[Rusnzha]

I tried to do a search on L100 replacement caps or something close to that and I wound on on a thread about people getting kicked off the forum. I am collecting the parts to rebuild my L100A crossovers. I have 4 50 Watt/8 ohm Lpads from Allied (Parts express was out till August), 4 .01 ufd Kimber polypropolyne caps from Parts Express and 4 5100 pf polystyrene caps purchased locally. The question is - should I replace the existing caps on the crossover and what do you recommend in their place?

Thanks, Russ

[4313B]

I wonder why those Kimber metallized polys are more expensive than the AudioCap film and foils...

I wonder what it is lately with these expensive metallized dielectrics like Kimber and Auricap... too many damn cap choices these days

Anyway, I'd just install the bypass caps you got and see what you think. The cheapest replacement main caps might be those Carli mylars Madisound sells.

[Rusnzha]

I finally finished upgrading my L100 crossovers. I used .1 ufd (not .01) Kimber polypropylene caps and 5100 pf polystyrene caps. I got 50 Watt L pads from allied with 3/4" shafts. I used UnDo to lift the foilcals and it worked like a charm. With all of the L100's innaccuracies and their wonderful results, I never considered the L166s or L112s to be upgrades. This was an upgrade! It was a little like listening to them on acid. They had a new clarity, definition and spaciousness. I want to say thanks to all of you answered my questions and shared your knowledge through Lansing Heritage. These old JBLs have even more value because of you.

There was one problem about shaft length. With the Parts Express L pads, they had to be backed off with plexiglass because of the 1" shaft length when you installed them. When I found the 3/4" shafts at allied, I thought I had it made. When I took the speakers apart, it looked like I needed 1" shafts due to the thickness of the cabinet plus the thickness of the board the crossover was on. The end result was that my crossover knobs are recessed 1/4". Obviously, I won't go back to the old L pads, but does anyone have a solution for this one. Are there some extenders or something that I can use to get them flush again? Thanks again -- Russ

[Don C]

There must be more than one way of measuring the shaft length. I think that Parts Express just gives the length of the threaded portion of the shaft. I don't know how to fix too short, too long was easier.

[scott fitlin]

There is such a thing as shaft extensions for pots, give this pot company a call!

http://www.state-elec.com/

[Ralphh]

After reading this thread, I have a question on the crossover updates. What does the .1ufd bypass Cap. do?

[Earl K]

Hi

Here's a link to a thread specifically designed to answer questions about "Bypassing" & Charge-Coupling ™ .

Cheers

[Ralphh]

Thanks for the information, which leads to another question. I have read descriptions of several members modifications to the L100 crossover. What would be the difference in using a .1 or a .01 bypass capacitor? Thank you for your response.

[Zilch]

They both work.

I believe JBL started out using 0.1 uF, but settled on 0.01 in later designs.

If it's in parallel with a 1.0 uF capacitor, you can see 0.1 uF will shift the value 10%. Not good, unless you want that.

Used with a 20 uF capacitor, it don't matter one whit....

[Ralphh]

Thanks for your response.
In reading this entire thread, I didn't find a description by "Audiobeer" of the finish applied to these cabinets. Could you post the steps you did in the refinishing process, and what products you used? The results look wonderfull.

[Earl K]

Hi

Please read : "Dolly Gets a Face Lift" . AudioBeer explains all of his magic within that thread .
- Please "BookMark" it for future reference .

- ( found with the Search Function by a senior )