Have these Caps been bypassed in this picture ??

[scm]

This is a picture of the capacitors (circled) for the midrange on some speakers I`m going to freshen up.

I`m going to replace those 4 Nichicon`s with a single higher rated cap. The originals are about 34 years old.

What I`d like to know is, is it worth putting in a more expensive cap with tighter tolerances ?
I ask because the original caps are soldered to the 'Green Box' shown in the picture which says +- 10% ?

 

[scm]

Ok, almost 50 views and no answer yet, so in the mean time... 'What IS that green box, and can/should be replaced with something better ??'

 

[Scottmoose]

Yes, from a quick glance it looks strapped across the electrolytics. Probably a Vishay (as now) MKT1822 or similar.

 

[tsmith1315]

Those electrolytics appear to be parallel pairs wired in series, bypassed with the green cap.

 

[Brinkman]

Yes, it looks like those four 50v 100uf electrolytic capacitors have been combined in a series-parallel combination to create a single 100v 100uF capacitor. That green box looks like a poly stacked film capacitor and looks like it is bypassing it. No way to be sure without multiple angles.

 

[Kay Pirinha]

Yes, it is a film capacitor. Capacitance value, voltage rating, manufacturer and type are written either on the other side that shows towards the board, or on the top (the left handed side in the pic).
Best regards!

 

[ICG]

Yes, that's how it's connected, 2 parallel in series with an identical pair. The purpose is to double the voltage rating of the capacitors. Not a good decision sound wise but good for handling high(er) power and safety - the electrolytic capacitors can explode if fed too high voltage.

 

[scm]

Thank you gentleman.
So before I order new caps/cap would it be worth it to put a nicer cap in, like a Clarity or Solen rated somewhere between 250V-400v ?

Should I eliminate that Green film cap altogether then ?

I`ve got a few more pics of the entire crossover including the subwoofer if need.

 

[ICG]

Replacing the 4 serial/parallel caps with one of the same capacity as one of the 4 will improve the sound quality by a great margin. The quality of film caps are generally higher than the electrolytic ones, even if they are older. It will not change much in SQ and since the film caps don't age like the e. caps, I'd keep it. It's likely there to increase the value of the Cs anyway and needed for the filter setup.

 

[scm]

Replacing the 4 serial/parallel caps with one of the same capacity as one of the 4 will improve the sound quality by a great margin. The quality of film caps are generally higher than the electrolytic ones, even if they are older. It will not change much in SQ and since the film caps don't age like the e. caps, I'd keep it. It's likely there to increase the value of the Cs anyway and needed for the filter setup.

Thanks..So I can put a single higher quality cap in and notice better sound, I like that.
But, being uneducated in this stuff I need to ask; Can I can put a better film cap in with tighter tolerances than the +- 10% one that`s in there now ? and will I hear an improvement ?

 

[ICG]

Thanks..So I can put a single higher quality cap in and notice better sound, I like that.

Yes, a single 100µF one with a higher voltage rating will bring more clarity and resolution.

But, being uneducated in this stuff I need to ask; Can I can put a better film cap in with tighter tolerances than the +- 10% one that`s in there now ? and will I hear an improvement ?

You can replace it but I doubt you'll hear a difference. The capacity is almost completely given by the electrolytic ones anyway, so if you want to have tighter tolerances, you'll have to start there.

 

[AllenB]

100uF is a value more easily found in electrolytics, otherwise it is quite large. Maybe this is in the woofer circuit, and maybe this setup isn't causing a problem. Nichicon are not a bad brand.

 

[scm]

100uF is a value more easily found in electrolytics, otherwise it is quite large. Maybe this is in the woofer circuit, and maybe this setup isn't causing a problem. Nichicon are not a bad brand.

Hi, this is the mid section for certain. Here`s a picture of the caps for the subwoofer section. The caps are glued to the side wall of the cabinet.

I can`t get the second picture orientated correctly You can see the mid range caps which would be the floor.

 

[oon_the_kid]

Since it is only 100uf, you can actually replace the electrolytic with a film cap. Panasonic has a PP for about US$20+ from Farnell/mouser/digikey..
Edit:

Here it is..

EZP-E50107MTA Panasonic | Mouser Singapore

Oon

 

[Kay Pirinha]

Replacing the 4 serial/parallel caps with one of the same capacity as one of the 4 will improve the sound quality by a great margin.

Yes, a single 100µF one with a higher voltage rating will bring more clarity and resolution.

I'm sure you have some proof for this claim, don't you? Or an explanation, at least, that's based on science?
Remember: This series-parallel onnection of four equal capacitors not only keeps the capacity of a single one, but also it's ESR. So, where should any sonic difference result from?

OTOH, I doubt it's use as well. Why do we need a voltage rating of 100 Vac in a - proposedly - home speaker? This would equal 2500 watts @ 4 ohms or 1250 watts @ 8 ohms?!?
Best regards!

 

[eriksquires]

Seems like they are attempting some of the same construction some boutique film caps use.



The reason Mundorf Supremes are so large is their series construction.


The parallel/series electrolytics probably helps reduce ESR, but may add inductance.



I would absolutely replace every single cap there. Replace the electrolytic banks with Mlytics, and the single SCR caps with anything decent.





However, it may be worth while measuring the electorlytic banks first, to ensure you don't severely change ESR.

 

[Kay Pirinha]

Yes, I'd also do, 'cause I'd not regard hotmelt glue as good engineering practice .
Best regRDS1

 

[Cal Weldon]

This appears to be a homebuild using K3 or particle board and hot glue. The holes were cut by hand with a jigsaw and there does not appear to be any rebating. The person appears to have used what was on hand to achieve the desired values.
Please tell us more about these speakers before you go too much further.

 

[scm]

Seems like they are attempting some of the same construction some boutique film caps use.



The reason Mundorf Supremes are so large is their series construction.


The parallel/series electrolytics probably helps reduce ESR, but may add inductance.



I would absolutely replace every single cap there. Replace the electrolytic banks with Mlytics, and the single SCR caps with anything decent.





However, it may be worth while measuring the electorlytic banks first, to ensure you don't severely change ESR.

Thanks Eric...I`ll need you to dumb it down for me if you will...sorry but I`m not very knowledgeable as to what some of those are that you mention.
Like what is a "single SCR cap" ? and what is ESR ?

So far, from what I`ve gleaned from various forums, I was thinking of using 2-Mundorf Ecap`s 100uf 100v to replace the 8 Nichicons going to the subwoofer.

And, either a Solen PB-MKP-FC 100uf 400v for the midrange or a Clarity CMR or CSA on the upper end (to me).
Or an Audyn that had been suggested for not a lot of money instead.

Thoughts ??

 

[scm]

Yes, I'd also do, 'cause I'd not regard hotmelt glue as good engineering practice .
Best regRDS1

It`s some sort of epoxy I think, hard as rock !