Replacing Old Filter Caps...And Why You Should

[wkcchampion]

I agree Marty, a lot to learn here.

 

[diesect20022000]

I'm so glad you put this up. I just got asked today aboutt his and i had to give the run down on it but, this is much more in depth and gives some info on the effects of not replacing them too which is great!

 

[TwinACStacks]

First thing I did when I traded the DSpLexi for my 2204 is order caps from AES. I went with the CE. Great caps I've used them before never had any problems with them, are the F&T that much better?

TWIN

 

[peterichardz]

When I change caps, I date code them so I (or the next guy)knows how old they are.

 

[lespaulboy]

I've got two new F&T 500V 50uF/50uF caps coming today for my JCM900 and have a really basic question.

My old LCR caps have a ground or common terminal, a "yellow" terminal and a "red" terminal. I don't have the F&T's yet, so I don't know if they are color coded the same. At the end of the day (as long as you have correctly identified the ground / common terminal) does the color coding really matter... this is essentially two 50uf caps in one convenient package... correct?

 

[Lane Sparber]

The terminal by itself is negative...the two next to each other are positives. No color coding necessary, and, yes, these caps can be thought of as two separate caps with a common negative. When replacing, just follow the layout and orientation that's in there now and you should be golden.

For example...OLD caps (LCRs) BEFORE:

Finally, NEW caps (F&Ts) AFTER:

-Lane

 

[lespaulboy]

Awesome... thanks for the quick response!

 

[Lane Sparber]

Hey, folks!

I'm just popping by for a sec to update/revive this thread in order to clear up a couple of misconceptions I've seen floating around here recently.

1. ALL electrolytic caps dry out over time. Yes, even the filter caps in solid state amps. After 10 years or so, they should at least be checked on a decent capacitor checker. If you don't have a cap checker, why not simply replace the caps as a precautionary measure at the very least? Especially on said solid state amps, the caps are VERY cheap to procure, so why not get those old caps out of there and sleep a bit easier at night?

2. Almost all electrolytic caps are NOT sealed. This is why they all dry out over time. It is true that if you use the amp often, it slows down the process considerably, but I assure you that they DO degrade, and often in this circumstance (frequent usage), their deterioration is so gradual that you don't really hear it happening...until a new set of caps is installed, that is.

The techs (myself included) aren't just saying this for our health. I don't own stock in F & T, Sprague, Mallory or any of the others. We've just learned through research and hard-earned experience how the components we work with behave - it's our job! For the record, most of the data sheets for electrolytic caps list their life-cycle expectancies. What does that tell you?

Cheers for now!

-Lane

 

[Lowlife]

Good thing to revive this thread, it really should be stickied. It's one of Wilders best in my opinion. I linked to it recently, because i haven't seen as good info elsewhere, took me a while to find it though.

 

[FourT6and2]

Sorry for the old-thread bump. But hey... I gots me some questions

Building a 50-watt clone. Kind of a 2204 circuit. The first cap after the standby switch has a 220K bleeder from the first 50uF section to ground. I disconnect that bleeder from ground, then place a 100K/2W resistor in series with the other side's 50uF positive terminal to the SS rectifier? Then just power the amp up (no tubes)?

 

[Exotic]

why do people use photobuckets? photobuckets go bad? fuzzy blurry?

 

[FourT6and2]

why do people use photobuckets? photobuckets go bad? fuzzy blurry?

You bumped a 10-year-old thread to complain about Photobucket?

 

[mickeydg5]

*****E-x-o-t-i-c-!*****

 

[Dogs of Doom]

why do people use photobuckets? photobuckets go bad? fuzzy blurry?

photobucket used to be considered the internet standard for free image hosting. Then, 1 day, they decided to change, that they were going to charge for the image space, or, they would stop allowing images to be seen in forums.

Using their site for image hosting, for forum posts was their largest usage, so, they literally killed millions of threads, as far as being viable for illustration, or archive...

 

[Exotic]

omg that was so great i haven't laughed so hard in a very long time!
of course i did just wake up from a nap and i'm feeling a bit loopy

 

[MickeyJ]

yes I see the logic.
I'm going to change my 50y/o caps which work and make my amp sound non-bright and non- shitty, for shitty bright sounding modern caps!
All because the mains fuse may not blow?
No thanks, Ill keep my caps.
You left the bit out that says,' for some reason old filter caps sound great.'
When they balloon at the top, or when I hear ghosting, I'll change them.
Thanks for being so concerned about my amp.

 

[MickeyJ]

For the record, most of the data sheets for electrolytic caps list their life-cycle expectancies. What does that tell you?

Judging by the amount of amps I've seen in the last year with original filter caps that are up to 55 years old, it tells me it's a pile of bullshit.

Judging by the amount of amps I've repaired in the last 20 years that distinctly lacked catastrophic secondary effects of a filter cap short, I submit a further bullshit call.

Why oh why would a manufacturer tell anyone that they need to give them more money every ten or fifteen years?

The original ones used in fender with paper around them, I agree. Cap cans, I don't agree unless there is leakage, blown out top or ghost notes.

 

[paul-e-mann]

yes I see the logic.
I'm going to change my 50y/o caps which work and make my amp sound non-bright and non- shitty, for shitty bright sounding modern caps!
All because the mains fuse may not blow?
No thanks, Ill keep my caps.
You left the bit out that says,' for some reason old filter caps sound great.'
When they balloon at the top, or when I hear ghosting, I'll change them.
Thanks for being so concerned about my amp.

Judging by the amount of amps I've seen in the last year with original filter caps that are up to 55 years old, it tells me it's a pile of bullshit.

Judging by the amount of amps I've repaired in the last 20 years that distinctly lacked catastrophic secondary effects of a filter cap short, I submit a further bullshit call.

Why oh why would a manufacturer tell anyone that they need to give them more money every ten or fifteen years?

The original ones used in fender with paper around them, I agree. Cap cans, I don't agree unless there is leakage, blown out top or ghost notes.

I'm no tech but I feel the same. My amp is almost 40 years old and looks and sounds great why change anything! My tech looked it over and said more or less the same, he did make me aware an old amp will need a cap job eventually and educated me on what to look for but did say everything looks fine so no hurry to change anything right now. So as a preventive measure I open my amp up about once a year and do a visual inspection and check the bias which never needs adjusting its rock solid.