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Leaking caps question
Posted: Sat Jun 16, 2007 5:57 am
by fordtough1
I know the caps leak on MS, M, and ZX amps due to age. Is this going to be a problem on other amps as they get older. Like the Ti amps for instance, or Xenons?
If so, how often should you open the amp and looks for signs of leaking? Or is it a good idea just to replace them?
Posted: Sat Jun 16, 2007 9:47 am
by marko
good idea just to replace them especially as it's an easy job on the zx and ti amps! apparently it was a bad batch of caps that made themselves into many old pg amps, i did one of my ms amps recently and it was a pain to do as there's all the devices to undo etc.. still got an ms2125 and ms2250 to do as well!
Posted: Sat Jun 16, 2007 1:22 pm
by 1moreamp
ALL electrolytic caps fail with time. Caps have a 5 year shelf life by most manufacturers. I would go with the manufacturers rating of 5 years of age MAX just to be safe.
The caps your talking about take a beating from the high frequency energy coming off the power supply, and your noisy 12 volt system, and hard cycling through charge and discharge. They do a dirty job well but for only so long.
Class D amps are even harder on caps.
I found some litmus paper on e-bay and I use it like a wick and slip it underneath each of the caps.
If it comes back wet, and or changed in color YOU have bad caps and they must be replaced or at least removed quickly. Of you will be sending your amp to the good Doctor Fosgate for circuit board repair.
Hope this helps C

Posted: Sat Jun 16, 2007 1:56 pm
by fuzzysnuggleduck
I need to do this on both my M44 and my M100.
Posted: Sat Jun 16, 2007 2:14 pm
by 1moreamp
fuzzysnuggleduck wrote:I need to do this on both my M44 and my M100.
Theres a guy on e-bay < located in China> that sells Panasonic 8200 ufd 16 volt caps that are the exact same size as you old 2200 ufd 16 volt caps. They cost a little less than $2.00 each with shipping. They are high grade 105 degree C rated, or you can order them from Digi-key, Jameco, Mouser.
I use this search engine to find then in the US:
http://www.findchips.com/avail
Just type in the description of the cap and hit search
C

Posted: Sat Jun 16, 2007 7:35 pm
by fordtough1
1moreamp wrote:ALL electrolytic caps fail with time. Caps have a 5 year shelf life by most manufacturers. I would go with the manufacturers rating of 5 years of age MAX just to be safe.
The caps your talking about take a beating from the high frequency energy coming off the power supply, and your noisy 12 volt system, and hard cycling through charge and discharge. They do a dirty job well but for only so long.
Class D amps are even harder on caps.
I found some litmus paper on e-bay and I use it like a wick and slip it underneath each of the caps.
If it comes back wet, and or changed in color YOU have bad caps and they must be replaced or at least removed quickly. Of you will be sending your amp to the good Doctor Fosgate for circuit board repair.
Hope this helps C

Yeah, that was exactly the information I was wanting. I thought that was probably true, but I wanted to hear it from someone with electronics experience. Good info as always. Thanks Cecil.

Polypropylene vs Polyester vs Electrolytics
Posted: Fri Jun 22, 2007 4:27 pm
by easy
I have old school Orion XTR450 that uses all of those caps.
Would like to replace them all.
What is the general rule?
Can I replace them all with electrolytics if place permits?
Note: On X100.4 or X200.4, I see 470uF 25V input caps. Can 1000uF 16V be used? What is the highest input voltage that these caps see?
Re: Polypropylene vs Polyester vs Electrolytics
Posted: Fri Jun 22, 2007 9:26 pm
by 1moreamp
easy wrote:I have old school Orion XTR450 that uses all of those caps.
Would like to replace them all.
What is the general rule?
Can I replace them all with electrolytics if place permits?
Note: On X100.4 or X200.4, I see 470uF 25V input caps. Can 1000uF 16V be used? What is the highest input voltage that these caps see?
16 volt will work. If you blow your alternator you might see more than 16. Most 1 farad caps are only rated at 20 volts DC.
Orion's generally are just like any amp, so yeah replacing your electrolytic type caps in the power supply will improve the amps SQ and operation.
ALL ELECTROLYTIC CAPS wear out with age and use, and abuse. The makes of caps only give them a 5 year lifespan and thats in a perfect world.
I replace 2200 ufd 16 volt caps with 6800 and 8200 ufd at 16 volt caps. because :
1: cap technology and Chemistry has changed over the last 15 years, SO you can get caps 4 times bigger inside, and still the same size outside.
2: New caps with better chemistry are supposed to last longer.
3: Increasing the capacitance on the 12 volt side will only help the power supply.
Orion likes to use Tantalum caps in the audio circuits as bypass capacitors for the + & - 16 volt power supply. They use these at every Op-amp in the front end of the amp. These like to short out and cause the amp to blow. Hifonics and others use Ceramic caps. Ceramic caps rarely if ever short out, and according to most folks you can't hear the Ceramic caps . So look into replacing your tantalum caps with Mylar or ceramic. Of all of those I prefer Mylar type caps anywhere near the audio circuitry. Buts thats just me.
I hope that explains things well enough for you, most of it is IMHO C
