Old JBL caps are not soo bad!

[Guido]

Last night I modified one of my 4343 xovers with new caps.

I bypassed the 72 (Bass) and 52 uF (**) (Mid) with 0,01 polyprops and polystrenes.
The 20 uF of MF, the 13,5 1,5 and 4 uf of HF were replaced with Audyn caps and bypassed with 0,01 polyprops.
The 1 (*) and 1,5 uF of the UHF were replaced with extreme expensive Caps Audyn Plus (no Bypass).

Yes. the sound is improved. But I must say that the stock 4343 which i will keep stock for some more weeks sound close!

Surprised!

(**)
The schematic says that in some units a 4uF cap is paralleled to the 52uF. My crossover has this. What could have been the reason?

(*)
The 2 uF cap from the UHF part is in my xover a 1 uF as it was in the 3141. Why this?

Anybody knows about this?

[4313B]

Originally posted by Guido
Yes. the sound is improved. But I must say that the stock 4343 which i will keep stock for some more weeks sound close!

Surprised!

Yes, very surprised. The guys at JBL notice a substantial difference.

JBL would never bother with adding the cost of bypass caps into any system if the practice didn't offer a marked improvement. I'm not going to go on a JBL rant as it would serve no purpose. I will say, if you don't notice a very pleasant difference then something else is wrong. I've bypassed a veritable plethora of older JBL loudspeaker systems that were manufactured before the L110A and the results have always been quite decent. Not a single person ever said "Yes. the sound is improved. But I must say that the stock JBL sounds close!" Not one. In fact, the usual comment is "Wow! That's some bang for the buck!"

[4313B]

Set the switch on the back to bi-amp mode and get that 52 uF cap out of the circuit. See how the 10-inch 3-way with the new fancy caps sounds then.

[Tom Loizeaux]

(**)
The schematic says that in some units a 4uF cap is paralleled to the 52uF. My crossover has this. What could have been the reason?

(*)
The 2 uF cap from the UHF part is in my xover a 1 uF as it was in the 3141. Why this?

Guido,
My 4343 crossovers had this 4uf paralled with the 52uf as well. I've read that bypass caps should be around 1% of the original cap's value. It appears that JBL decided to bypass the 52uf to improve the overall performance and also felt that the 52uf value could be improved by making it 56uf!
Since I bi-amp my 4343s, I don't run any signal through these big caps anyway.

I am curious how you would describe the differance imn the 2405s since changing the 1 and 1.5 caps to "high end" versions.

Tom

[Guido]

Hi there!

I wouldn't start another cap rant!

First of all I think that the new caps must break in. Today everything start to sound a little bit less "edgy"

I need to listen more carefully. I just didn't have this Wow feeling Giskard described. But I was tired anyway.
And we should not forget that I still don't have the 2121. But it is on the way thanks to giskard


Giskard, one is for sure: With the 5235 and Bi amping the sound is much more improved.
Thats why I wondered why JBL installed this 52 uF before the upper 3 ways.
I will keep one 4343 stock until I receive the 2121 from you and then will do extensive testing with internal and external xover.

[Rafael]

This is no surprise: the difference between the yellow foil caps JBL used and most of the „audiophile“ caps is mainly the color and the labeling. All caps are relatively cheap made and the materials used are not so expensive. We tried many types of caps using switches for correct a/b tests. We found out that the caps sounded slightly different but there was no way a certain cap could be clearly auditoned as “better”. The slightly smooth sound of the stock JBL caps is no disadvantage with compression drivers.

Regards,

Rafael

[4313B]

We could go round and round with this cap crap until the cows come home and still end up with nothing. If you can hear a difference between something like a Hovland and an old metallized mylar then great, if you can't then you just saved some money. Go take a girl to dinner and a movie instead then. Whatever...

[Mr. Widget]

Originally posted by Giskard
Go take a girl to dinner and a movie instead then. Whatever...

You know, I think I'll stick to playing with caps. Everytime I play with the girls my wife gets really pissed.

Widget

[Guido]

Widget:
Wise Wise

Giskard:
I wrote no rant please.
I just wanted to share my first impressions. You're right. All this can only be discussed while all together sitting in front of a stock and a modified speaker and doing A/B a whole night.

[4313B]

Originally posted by Guido
Hi there!

I wouldn't start another cap rant!

First of all I think that the new caps must break in. Today everything start to sound a little bit less "edgy"

Actually the rant I was avoiding going on had to do with generally cutting costs as opposed to caps specifically.

You appear to be right about "breaking in" caps. I've noticed this phenomenon before. I've found that after installing bypass caps and then acclimating to the loudspeakers for a period of a few weeks then removing the bypass caps the difference was "Eeeew!" I ran across this several times when I was trying different dielectrics and would listen between taking out the previous bypass and putting in the replacement bypass. Anyway, whatever floats your boat.

Originally posted by Mr. Widget
Everytime I play with the girls my wife gets really pissed.

Well, there's that...

[boputnam]

Originally posted by Mr. Widget
Everytime I play with the girls my wife gets really pissed.

Well, Widget, I gotta say I never saw that side of your wifey...

[Mr. Widget]

Let's just say it isn't pretty.

[Ian Mackenzie]

Widget,

I hope I don't get you guys into trouble....LOL

Ian

[Mr. Widget]

Originally posted by boputnam
Oh well, my humour here is sooo abstract, that not even a San Franciscan can get it - guess I'll delete and move on...

Bo,

Is there something you want to tell me?

[Alex Lancaster]

Widget:

How about boys?