I have a Sony TA-f808es integrated amp not working I posted on another thread. I was advised to test the filter caps, so hence this posting about the caps.
This post is about testing and locating replacement for the massive screw-type electrolyte filter caps (show in the enclosed photos).
They are Elna 'for audio' 15,000 uf, 63v, 85ºC behemoths, measuring 63mm dia. x 104mm high to screw terminal. (Diameter is important as they fit into a plasitc clamp mounting bracket.)
I have a Fluke 179 multimeter, but capacitance test limit is 10,000uf so testing them reads 'OL' (over the limit/range).
I'm a novice and don't know how to test leakage, but here are my other readings if they mean anything:
Left cap: / Right cap:
41.04 ohms / OL
.985 DC volts / 1.2 DC volts
Do my results mean anything, and how do I test leakage?
Do my results reveal that I need to replace them?
I searched high and low and can't find replacements to match on-line?
This post is about testing and locating replacement for the massive screw-type electrolyte filter caps (show in the enclosed photos).
They are Elna 'for audio' 15,000 uf, 63v, 85ºC behemoths, measuring 63mm dia. x 104mm high to screw terminal. (Diameter is important as they fit into a plasitc clamp mounting bracket.)
I have a Fluke 179 multimeter, but capacitance test limit is 10,000uf so testing them reads 'OL' (over the limit/range).
I'm a novice and don't know how to test leakage, but here are my other readings if they mean anything:
Left cap: / Right cap:
41.04 ohms / OL
.985 DC volts / 1.2 DC volts
Do my results mean anything, and how do I test leakage?
Do my results reveal that I need to replace them?
I searched high and low and can't find replacements to match on-line?
Attachments
When you say "not working"...did you measure the power supply voltages? The best way to measure an electrolytic cap is with an E.S.R meter. You can use a bigger cap like 18000uf or even 20000uf...not a problem. As long as they are same voltage rating or higher all will be fine.
I do not know how old is your amp but, usually when a cap is very old (20 years or more) you should change it!
I do not know how old is your amp but, usually when a cap is very old (20 years or more) you should change it!
If you've got the caps out of the amplifier, try them with a DC supply to see if they are the cause of the failure.
Amp is from '93.
The caps are out of the amp, but don't know how to test w/ dc supply.
By the looks of the caps terminals is looks like there are two caps in each can so I could cut them open and put 2 caps in each can so they will fit back the amp if I have to.
The caps are out of the amp, but don't know how to test w/ dc supply.
By the looks of the caps terminals is looks like there are two caps in each can so I could cut them open and put 2 caps in each can so they will fit back the amp if I have to.
Don't cut them open.
Search for the method to measure leakage current and the method to determine ESR.
Download the datasheet to see what the specification is.
Search for the method to measure leakage current and the method to determine ESR.
Download the datasheet to see what the specification is.
Try these: LNT1K153MSE Nichicon | Mouser
just hold them with black silicone on the sides.
I found the same brand in 22000uf but it is 63.5mm dia.
just hold them with black silicone on the sides.
I found the same brand in 22000uf but it is 63.5mm dia.
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Other way just place back the caps, plug the cord & measure the DC voltage on them...
usually DC voltage on caps is VAC * 1.414 or just a little less...
if you can disconnect all the load, just trafo, bridge diode & elco's...
That for now so we know what cause this amp dead, maybe no by the elco's they looks good 😀
usually DC voltage on caps is VAC * 1.414 or just a little less...
if you can disconnect all the load, just trafo, bridge diode & elco's...
That for now so we know what cause this amp dead, maybe no by the elco's they looks good 😀
Since your amp is 20 years old, I would check "ALL" those electrolytic caps. and also check for bad connections on the bottom of boards. Those Sony "ES" series run really hot and that heat will help drying out caps and end up with bad solder joints too.
PS: I would NEVER trust an electrolytic cap for it's look.
it can be a "brand new"...but it can be dry-out!.
it happened to me a few times when I used to fix electronics. (old stock)
PS: I would NEVER trust an electrolytic cap for it's look.
it can be a "brand new"...but it can be dry-out!.
it happened to me a few times when I used to fix electronics. (old stock)
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I check electrolytic caps with a calender. Once the amp *****s up, age>20 years, out they go, starting with the ones near the power transformer. The meter with ESR scale for that big a capacitance is $140 at newark.com, or 6 months of fiddling with a schematic off this site. And a diy meter is not calibrated. I hate buying new meters, they last only 1 -2 years seems like; if something is not cheaply built the company is bankrupt these days.
The new caps I buy >3000 hour service life if I can get it.
I've made cap sandwiches out of scrap polycarbonate plastic, 18 ga bus wire, 2" #6 machine screws, and silicon seal glue, to save money on giant caps. 6 each 4700 uf caps are way cheaper than two 15000 uf caps. I screw the assembly to the board some way, as these things are heavy and could break loose if the amp was banged around.
The new caps I buy >3000 hour service life if I can get it.
I've made cap sandwiches out of scrap polycarbonate plastic, 18 ga bus wire, 2" #6 machine screws, and silicon seal glue, to save money on giant caps. 6 each 4700 uf caps are way cheaper than two 15000 uf caps. I screw the assembly to the board some way, as these things are heavy and could break loose if the amp was banged around.
If no ESR meter is present, one can also look at ripple on the supply rails with a scope.
BTW, these big can-type caps from reputable manufacturers usually last a long time in regular domestic use. Good quality parts can be as good as new after 40 years in some cases. Even if they do fail, nothing dramatic happens - you may not even notice the reduced peak power until eventually the unit starts to produce audible hum. We're usually talking ~35-year-old units at this point.
Obviously, a PA amplifier that has seen its share of abuse in hot climate is a whole 'nother kettle of fish. Plus, a sample size of one may deviate from statistical average by an arbitrary amount.
BTW, these big can-type caps from reputable manufacturers usually last a long time in regular domestic use. Good quality parts can be as good as new after 40 years in some cases. Even if they do fail, nothing dramatic happens - you may not even notice the reduced peak power until eventually the unit starts to produce audible hum. We're usually talking ~35-year-old units at this point.
Obviously, a PA amplifier that has seen its share of abuse in hot climate is a whole 'nother kettle of fish. Plus, a sample size of one may deviate from statistical average by an arbitrary amount.
Just connect them to a DC supply and see if they charge up. Then disconnect the DC supply and see if they hold their charge. This will be a VERY BASIC indication of their functioning. At this moment you are just trying to ascertain what has caused the amp to fail. They might well be leaky and they might well be faulty but if they still function as caps the amp will work to a fashion.
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There have been some very good posts provided on the forum in response to your question about testing BIG caps but if you are a novice some of the advice may not be appropriate or easily applied with your present knowledge, so let me summarize some reasonable options for you.
a) First of all finding out why the amp is not working would be my first priority, and if it is because of the CAPS then great, but if not you still have a more important task to pursue.
b) Agree with the post that talks about measuring the ripple on the power supply with the caps in-circuit, this will tell you much about the health of the power supply (PS) circuit (but not thoroughly determine individual CAP characteristics) and you would need an oscilloscope and the know-how for hooking it up safely to measure the AC ripple on the DC voltage rails of your amps power supply...again maybe not your thing and there is high amperage here that can be dangerous and harmful.
c) Since you already have the CAPS out of circuit (and hopefully properly discharged them!) you can do some easy static testing as follows:
i) Buy a proper capacitance meter and measure the total capacitance on each CAP
- my experience is that this won't tell you much - bad CAPS can often measure at the right capacitance, even when bad
ii) Buy a cap charging meter that used a 'rising' tone to detect charging and 'intermittent' tone to detect leakage of the cap
- may be useful but not if the problem is internal resistance
iii) Buy an ESR meter to measure the internal resistance of the cap - over time caps build internal resistance and often fail
- caps that are 3 - 10 times the internal resistance stated by manufacturer are problematic and could fail catastrophically
- by far the best choice for older or suspect caps is an ESR meter - you can build one in 3 days from this kit:
Ana Tek Corporation
After static testing is done you will know how healthy the caps really are and whether you even need to replace them. There is no expiration date on these BIG caps, but the ESR (equivalent series resistance) will usually tell you if an older cap is in trouble. This meter sends a 'smart' pulse-signal through the cap at VERY high frequencies to cleverly measure equivalent series resistance inside . Regarding replacement parts, finding exact replacements for caps/clamps is part of the 'fun' of this hobby since most manufacturers of original caps are long out-of-business by the time they actually fail, finding the right size and specifications for any cap requires careful research and plenty of money ($$). Good luck with your amp project.
a) First of all finding out why the amp is not working would be my first priority, and if it is because of the CAPS then great, but if not you still have a more important task to pursue.
b) Agree with the post that talks about measuring the ripple on the power supply with the caps in-circuit, this will tell you much about the health of the power supply (PS) circuit (but not thoroughly determine individual CAP characteristics) and you would need an oscilloscope and the know-how for hooking it up safely to measure the AC ripple on the DC voltage rails of your amps power supply...again maybe not your thing and there is high amperage here that can be dangerous and harmful.
c) Since you already have the CAPS out of circuit (and hopefully properly discharged them!) you can do some easy static testing as follows:
i) Buy a proper capacitance meter and measure the total capacitance on each CAP
- my experience is that this won't tell you much - bad CAPS can often measure at the right capacitance, even when bad
ii) Buy a cap charging meter that used a 'rising' tone to detect charging and 'intermittent' tone to detect leakage of the cap
- may be useful but not if the problem is internal resistance
iii) Buy an ESR meter to measure the internal resistance of the cap - over time caps build internal resistance and often fail
- caps that are 3 - 10 times the internal resistance stated by manufacturer are problematic and could fail catastrophically
- by far the best choice for older or suspect caps is an ESR meter - you can build one in 3 days from this kit:
Ana Tek Corporation
After static testing is done you will know how healthy the caps really are and whether you even need to replace them. There is no expiration date on these BIG caps, but the ESR (equivalent series resistance) will usually tell you if an older cap is in trouble. This meter sends a 'smart' pulse-signal through the cap at VERY high frequencies to cleverly measure equivalent series resistance inside . Regarding replacement parts, finding exact replacements for caps/clamps is part of the 'fun' of this hobby since most manufacturers of original caps are long out-of-business by the time they actually fail, finding the right size and specifications for any cap requires careful research and plenty of money ($$). Good luck with your amp project.
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