Do caps need to "warm" up..?

bcbud3

Well-Known Member
I purchased a pair of rtr tower speakers recently. I didn't listen to them before refoaming. I checked the continuity on the woofers before and they were fine. Once I got the woofers back into the cabinet and fired up they sounded dull and eventually tripped the resettable breaker. Pushed the button and they fired back up. Left them playing on low volume and they started to wake up. Same thing happened with the other tower as well. Is this normal? Just the electrons flowing through an old, dry cap..? Should I be worried? Is this normal with old speakers that haven't been played in a long time? I realize that a recap would be a good idea anyways at this age.
 
Those circuit breakers are junk...just bypass them. That's what I did on my RtR's and also on Norman Lab Model 9's. If you feel the need for protection, replace those old junk breakers with fuses. Otherwise, just practice safe sound. ;) Also, replace those old caps. Especially if they are those black caps with the red ends. Use some Dayton, Women, Audyn, ClarityCaps, etc...it will be tons better.

Which model RtR? Post some pics of them and maybe the crossover network.
 
When caps sit for a while they need to be reformed, which means slowly putting power to them. Basically using them for a while is similar to reforming them. If they are still good, a while on with power from an amp will reform them somewhat.
 
Is this normal with old speakers that haven't been played in a long time? I realize that a recap would be a good idea anyways at this age.

I've had that exact experience with long idle and old speakers. They sounded awful at first but improved dramatically the longer they played. This is from any electrolytic capacitors reforming. However, some won't reform and would remain sounding bad. At this point just replacing them all with new ones is not a bad idea.
 
On the subject of reforming: Electrolytic (polar) caps undergo this process because they have a paste with electrolytes (salts). Film caps do not have electrolyte, only dielectric (plastic) film between the foil layers. I don't know of a mechanism by which a nonpolar film cap could reform;. I've been surprised before though so don't take my word for it.
 
At the risk of taking the discussion about women's apparel off-topic... :)

I've read that the "newer" formulations of capacitor electrolytes don't need, or possibly aren't able, to be reformed. What general era (50's, 60's, 70's, etc.) are the capacitors from that would benefit from reforming?
 
I don't know the answer to that one.

And many speakers do not have electrolytic caps in them at all. You could tell by looking at the caps in yours. If you can post a pic it might be revealing. Any idea how old these speakers are?
 
On the subject of reforming: Electrolytic (polar) caps undergo this process because they have a paste with electrolytes (salts). Film caps do not have electrolyte, only dielectric (plastic) film between the foil layers. I don't know of a mechanism by which a nonpolar film cap could reform;. I've been surprised before though so don't take my word for it.

Mineral oil if I remember correctly from my military days. I don't believe there's a breakin, I think it's more of the listeners ears warming up than the caps.
 
As a collector, I power almost everything up for a time every now and then. My accountant, which I am going to see next Monday, has had the same Technics receiver running for decades as his personal office music source. IMO, I think caps live to be in constant charge (its their job).

Now that I think about it, my uncle Clarence (the farmer) had the same radio tuned to the same station for decades in the barn. It was never shut off, it was always on the same station (WCCO) and it must have kept the cows happy during milking or when they were in the barn during the long nights of the winter.

Funny how some things work (and some don't).......:)
 
I tried woman caps, but my wife complained when I tried to stuff her into the speaker cabinet. Besides I can only afford enough for one cabinet.
 
I don't know of a mechanism by which a nonpolar film cap could reform;. I've been surprised before though so don't take my word for it.

I give up on that one too. I have never had a film cap test bad, unless it was damaged (either physically or by some sort of other failure resulting in a high voltage spike). Just don't confuse an old PIO cap with a more modern film cap--totally different animals. Electrolytics are kind of a no-brainer, as it is a chemical reaction (think rechargeable battery) where upon charging, it may or may not return to function.

Back to the OP's original question, I don't know if the caps are electrolytics, but simply replacing the surrounds may have impacted the sound until they "loosen up". Sometimes new surrounds need a bit of time to get rid of stiffness and allow the driver to function properly.
 
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