Caps, L Pads and 5-Way Binding Posts for L100 & 4311

[cooperj]

Hello fellow JBL fans,

I’m hoping one of our sage members can help me with a few questions, please.

First, I’d like to replace the capacitors and L pads in my L100s and 4311s. I’m not looking for an upgrade or anything fancy, just replacing the components with high quality modern-day components. My hope is to maintain the sound characteristics of the original speakers. I searched the site and am aware the caps are 3 and 8 uf, but I’ve never seen anything about the voltage spec. Does anyone what that spec is? Also, what brand are considered high quality and where can I buy them? Unfortunately, the many links I’ve found here to companies that sell them are now dead. Similar questions for the L pads. Are there quality components out there and who sells them? I know they should be 8 ohms, but should I also consider linear vs audio taper? Again, the goal is to duplicate the original specs to the degree possible.

I also want replace the push-spring connectors used to connect speaker wire with quality, gold plated 5-way binding posts. There are numerous companies that sell them but I assume the dimensions are important so they fit properly. I’m fine with drilling out the hole to accommodate a larger diameter connector, but should the overall length, and the length of the connector inside and external to the speaker be considered too?

Many thanks in advance.

[Mr. Widget]

Agreed on the binding posts… those spring clips were terrible! I would use decent five way binding posts from Parts Express.

Parts Express should have appropriate L-Pads and a wide assortment of caps too.

Regarding the caps; I wouldn’t bother, but pick the caps of your favorite flavor. 100v or 250v will more than get the job done. The voltage rating just tells you what they can take before they arc. The rating shouldn’t affect the sound… but then neither do liquid cooled anti-vibrational speaker cable risers, but some will say, “Getting these cable risers was the best investment I have ever made in audio. They gave me a whole new record library.”


Widget

[RMC]

RE Widget's "...pick the caps of your favorite flavor. 100v or 250v will more than get the job done.

Recently purchased a dozen of Solen's yellow, 160 volt, 5% tolerance, polyester type caps for small satellite boxes in the making. Measured their capacitance on half a dozen of these caps with a precise multimeter. They were within 3% or so tolerance! nice surprise since this is the usual tolerance for their more expensive 250 volt caps... I measure these, as well as resistors i use, to minimize having a shift or using an odd one with poor value. Only a cap suggestion.

[FSTP]

I just got some nice vintage L100's. I too would like to replace those push spring binding posts. I don't know which binding posts I'm going to get yet but I look forward to seeing how you replace them. How do you get the old ones out? Are they screwed in or glued in? I assume one has to remove the woofer to get to them?


Thanks,
Jess

[Swerd]

I just got some nice vintage L100's. I too would like to replace those push spring binding posts. I don't know which binding posts I'm going to get yet but I look forward to seeing how you replace them. How do you get the old ones out? Are they screwed in or glued in? I assume one has to remove the woofer to get to them?I removed the woofer, and easily unscrewed the old spring binding posts from inside the cabinet. On my L100s, the binding posts were mounted through small Masonite boards, roughly ¼" thick. These short (13 mm long) binding posts worked well as replacements in the same holes that the spring posts used.

These posts now cost $3.25 each post. Order one black and one red post:
https://www.madisoundspeakerstore.com/yung-binding-posts/posts-g-postb-binding-post-black/
https://www.madisoundspeakerstore.com/yung-binding-posts/posts-g-postr-binding-post-red/

For $3.40 each you can get insulated binding posts:
https://www.madisoundspeakerstore.com/wbt-binding-posts/posts-sg-post-safety-binding-post-black/
https://www.madisoundspeakerstore.com/wbt-binding-posts/posts-sg-post-safety-binding-post-red/

[Riley Casey]

Five way binding posts allow larger wire and sometimes banana plugs but these also allow more stress on the masonite panel. These ( https://www.valuetronics.com/product/2383-0-pomona-accessory-new?gclid=CjwKCAjwieuGBhAsEiwA1Ly_nbmYAo4mYUzwVl3Z fetzkla-hSqojQq6VFseGb0i_BobGqWpUdzTzxoCycoQAvD_BwE ) were the standard of the industry for electronics test equipment and power amp outputs for decades and most custom made studio monitors used them too. The plastic base stiffened the masonite panel. If you don't use something like this its a good idea to add some flat washers under the posts on both sides of the masonite.

[grumpy]

I'd go a step further and just replace the masonite board altogether... it was often just glued and stapled in.
I've been able to push them in with a finger (perhaps my examples were less well cared for).
The staples vs screws thing could be specific to 4311a/b models.

Toss the whole thing in the bottom of the speaker for the next owner as an original item surprise. :D

[Mr. Widget]

I'd go a step further and just replace the masonite board altogether... For my projects I usually 1/4” thick black acrylic, but then I have saw blades specifically designed to cut acrylic. 1/4” black painted birch plywood would work well too.


Widget