Type & brande of capacitors in L-55

[moinau]

Good Morning,
Hi, I'm new here, and glad to join this forum.

I would like to know the type and the brand of capacitors, if possible, used on the L-55. I know this model use two 8uf capacitors, but would like to know more about them.
At this time, I can't open the speakers, take the driver woofer out, and take a look inside. As of now, I have the technical manual (crossover)
Thanks

[speakerdave]

Why? Are you planning on replacing them? They are probably a more or less generic NPE. You could replace them with Solens or the equivalent and bypass with small film and foil or polystyrene. If you want to optimize (and spend more money) you could get four double size Solens per speaker and charge couple. Or you could spend up on caps, as some people seem to prefer. There is much to read in these forums and elsewhere about crossover caps.

[fpitas]

If you plan on replacing them, it's hard to go wrong with a polypropylene cap, like this:

http://www.parts-express.com/kimber-...citor--027-884

You can also find cheaper polypropylene caps, although 8uF is an odd duck sort of value.

Francis

[Altec Best]

Agree with Dave on this..Speaker manufacturers used cheap generic caps back in the day with tolerances around 10-20%.Today you can buy them with tolerances at 5% or less.And they are the standard..The caps today are much better than the ones they made 30 years ago IMHO.Solens or Daytons are just fine, and they are reasonably priced.

Some values you may have to get in 2 different places like Parts Express or Madisound.. I usually shop at Madisound..For my Model 19 crossovers I had to use both places as I couldn't get a 3.9 Ohm resistor at PE.

https://www.madisoundspeakerstore.co...fast-cap-400v/

[fpitas]

Agree with Dave on this..Speaker manufacturers used cheap generic caps back in the day with tolerances around 10-20%.Today you can buy them with tolerances at 5% or less.And they are the standard..The caps today are much better than the ones they made 30 years ago.Solens or Daytons are just fine, and they are reasonably priced.

Some values you may have to get in 2 different places like Parts Express or Madisound.. I usually shop at Madisound..For my Model 19 crossovers I had to use both places as I couldn't get a 3.9 Ohm resistor at PE.

https://www.madisoundspeakerstore.co...fast-cap-400v/

Yeah, I agree; that Solen cap is fine for the job, and is a lot cheaper than the Kimber cap above.

Francis

[moinau]

Yeah, I agree; that Solen cap is fine for the job, and is a lot cheaper than the Kimber cap above.

Francis

Agree with Dave on this..Speaker manufacturers used cheap generic caps back in the day with tolerances around 10-20%.Today you can buy them with tolerances at 5% or less.And they are the standard..The caps today are much better than the ones they made 30 years ago IMHO.Solens or Daytons are just fine, and they are reasonably priced.

Some values you may have to get in 2 different places like Parts Express or Madisound.. I usually shop at Madisound..For my Model 19 crossovers I had to use both places as I couldn't get a 3.9 Ohm resistor at PE.

https://www.madisoundspeakerstore.co...fast-cap-400v/

If you plan on replacing them, it's hard to go wrong with a polypropylene cap, like this:

http://www.parts-express.com/kimber-...citor--027-884

You can also find cheaper polypropylene caps, although 8uF is an odd duck sort of value.

Francis

Why? Are you planning on replacing them? They are probably a more or less generic NPE. You could replace them with Solens or the equivalent and bypass with small film and foil or polystyrene. If you want to optimize (and spend more money) you could get four double size Solens per speaker and charge couple. Or you could spend up on caps, as some people seem to prefer. There is much to read in these forums and elsewhere about crossover caps.

Thanks to all, Dave, Francis, and Altec Best, for the replies, and your help.

Dave, sorry about that, I should of explained a bit better what my intentions were.

This is my first JBL speakers, I usually collect and repair (enclosure) AR speakers, but will be my first time replacing caps.
When I first got these, I did test them for a few minutes, making sure there was sound from all drivers. The speakers are in excellent condition, with the usual repairs expected. First, the U shaped supports glued or maybe nailed underneath, 1 1/2" by 2" pieces of mdf wood. Intend to replace same with plywood.

Second, the felt on top was rotten. I already scraped the residue, and will replace with new tick black felt, hot glued to top of speakers. Glass are in excellent condition, and so is the walnut veneered sides.

Next will be the Lansalloy suspensions. There is very little movement remaining with the surrounds, they are very stiff, and dried. I did read about the brake fluid approach, but decided to go with new surrounds. Decided to buy the surrounds from Mr. Cobb, and also some for some AR and PSB speakers, should receive them this week sometime.

Now for the caps. I've little or no experience how to re-cap speakers, but will learn by reading lots of your posts, and with some help here.
I was asking about type and brands of caps. I know that poly will last a very long time, but the ESR is quite different from NPE caps. I also read about Mylar caps, having similar ESR to the electrolytic.

Now my question is, is this a good way to go this route, understanding that Mylar and electrolytic wont last as long as poly, but should be much closer to the original voicing of this speaker. What do you think of this approach.

Since the Lancer takes two 8uf caps per speaker, I was thinking of four Carli MET 8uf NP Mylar 150v +/-10%
or, 4 Alcap 8uf high power 100vdc electrolytic +/- 2% or maybe the +/- 5%

Also, any advantage, better overall sound, better definition with the HF, etc... in using two 4uf caps in parallel to make the total value,

Last question,
What is a bypass cap, and what is its function. I understand it's usually of a very low value, 0.1uf or lower maybe.
I understand that some people use them, while other, don't.

Thanks all for your help,

André

A few pics,

[speakerdave]

You are sensible to try to avoid spending excessively on this project. Probably wouldn't worry myself much about the original voicing, since my guess is that this speaker design was targeted at acceptability and no more. If I were going to be putting in the time and energy I would be looking for little improvements. I'm not familiar with the caps you mention, but if the speakers are working at all I don't think I would get my hands into the Fiberglas to solder in a 95 cent replacement capacitor.

I would look for a solution among the suggestions that have already been made, but if you want to try something else, work out.

[moinau]

Hello Dave,
Thanks for your input, much appreciated. Good point in mentioning this fibreglass fill that was commonly used in the 70s, and 80s, nasty stuff if one doesn't take proper precautions.

What little improvement would you expect to see with this model, and where should I direct time and energy/money to achieve it.
I did some reading about this model. The L-55 has quite a good woofer, but sadly lack with its choice of tweeter, although some members here have grown to like this speaker.

André