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Post by nguyenphananh on Mar 16, 2021 18:32:23 GMT -5
I have a XPA-2 gen 1. Recently I need to open it up for service .... while the unit was opened, I notice on the main board, all the big capacitors were of cheap,unknown-chinese name, and seem like some of them started leaking (the amp still function fine). There are many discussions of this issue on this forum for many years now. Anyway, my question is if I replace these cheap Capacitors with HIGHER END, HIGHER QUALITY, brand name, equivalent or better specs/value.... will that improve the sound quality? significantly (can I hear the different)?? Have anybody experience with this?? any input or advice??. Thank you
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cawgijoe
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Post by cawgijoe on Mar 16, 2021 21:20:27 GMT -5
I have a XPA-2 gen 1. Recently I need to open it up for service .... while the unit was opened, I notice on the main board, all the big capacitors were of cheap,unknown-chinese name, and seem like some of them started leaking (the amp still function fine). There are many discussions of this issue on this forum for many years now. Anyway, my question is if I replace these cheap Capacitors with HIGHER END, HIGHER QUALITY, brand name, equivalent or better specs/value.... will that improve the sound quality? significantly (can I hear the different)?? Have anybody experience with this?? any input or advice??. Thank you Not sure if you will hear a sound quality difference, but if they are bulging or leaking, you should replace them. |
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Post by leonski on Mar 21, 2021 18:04:47 GMT -5
Bulge / Leak......REPLACE IMMEDIATELY.
Use a tier 1 capacitor.
https://gist.github.com/komidore64/2e6a342c91fc9b5e9bc457f48c5b0bae
Either Asian OR USA made would be fine. Replace with same temp rateing.....usually 85c or 105c. Some specs differ between the temp ratings.
Also? Several different connection types. I couldn't find DIRECT replacment for the 40 year old ELNA in my Kenwood KA-7100 integrated. Best I could do was
a different SPACING between connnections. Not a problem....and if I go ahead with this? I'll hold the cap in place with a DAB of Hot Glue while I solder. I like the screw-top caps, but those
are typically in larger sizes. You can connect 'em with a copper Bus Bar for the ultimate in conductivity.
If you want me to look? Size / Voltage and connection type would be nice. Digikey has a fine 'parts finder' IF you have the patients......
This is a 'commodity cheap' part and IMO, no reason exists NOT to use a top tier brand. That's just penny pinching of the first order.
CAPS could cost as little ast 3$ or 4$ each. Depends on size / voltage ......
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Post by leonski on Mar 24, 2021 14:40:29 GMT -5
I PM'd nguyenphananh and was told 'wrong guy'.......
Best of luck when those 'cheap caps' decide to pop.
A proper PS cap should last 20 years or more.....in regular use.
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DYohn
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Post by DYohn on Mar 24, 2021 15:15:16 GMT -5
Are you sure they are "leaking" or is what you see mounting cement?
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Post by leonski on Mar 24, 2021 16:54:34 GMT -5
Good Question DY!
I'd like to see a photo......
If I was the OP, I'd seek a 2nd, professional opinion....
Also? Do they solder to the board, if if so, do you know lead spacing?
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Post by vcautokid on Mar 24, 2021 17:32:55 GMT -5
Depending on many factors such as Equivalent Series Resistance, out of specification, bulging or leaking electrically or physically, electrolytic capacitors should be replaced. Seriously doubt if you would hear a difference. Get some good ones like Nichicon, or Panasonic HF and others out there. Digikey and Mouser are your common go too places. Just don't look at the filter capacitors in the power supply. Look at the the other capacitors too! A Gen 1 is getting up there in years and capacitors are cheap. I would recommend replacing all of them as a matter of course. It will prevent other problems down the road. Do it once and be good for another bunch of years.
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Post by leonski on Mar 24, 2021 22:18:24 GMT -5
The caps I listed at the Digikey link are a huge 35$ each.......That's a LOT for a aluminum electrolytic. I also linked a list of 'Tier 1' manufacturers. Sure, Vac, the names you mention are there but so is Elna and Rubycon....And a FEW from the USA..... I'd look for the Nelson Pass article on Capacitors. In it he says they should go 20 to 30 years......which I find to be true. the ELNA Caps in my Kenwood KA-7100 (late '70s?) are still FINE. I just tested it the other day. www.stereophile.com/content/nelson-pass-simple-sounds-better-page-2Pass mentions 10 years for PS caps. BUT, this is for warranty purposes during a major rebuilt.....In other articles he mentions 30 year lifetime for such parts... |
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DYohn
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Post by DYohn on Mar 25, 2021 9:53:40 GMT -5
The caps I listed at the Digikey link are a huge 35$ each.......That's a LOT for a aluminum electrolytic. I also linked a list of 'Tier 1' manufacturers. Sure, Vac, the names you mention are there but so is Elna and Rubycon....And a FEW from the USA..... I'd look for the Nelson Pass article on Capacitors. In it he says they should go 20 to 30 years......which I find to be true. the ELNA Caps in my Kenwood KA-7100 (late '70s?) are still FINE. I just tested it the other day. www.stereophile.com/content/nelson-pass-simple-sounds-better-page-2Pass mentions 10 years for PS caps. BUT, this is for warranty purposes during a major rebuilt.....In other articles he mentions 30 year lifetime for such parts... Yes, unless they are defective or used incorrectly electrolytics have a 30 year life easily. And their normal "failure" mode is not leaking, it is high ESR. |
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Post by leonski on Mar 25, 2021 18:42:41 GMT -5
Didn't know about ESR Failure Mode. Would have guessed 'bulge'. And from drying out thru disuse a distant 3rd....
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Post by audiobill on Mar 25, 2021 20:59:26 GMT -5
These lives are for good quality. Some audio companies prefer the cheap stuff.
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Post by leonski on Mar 25, 2021 21:34:08 GMT -5
Based on what I saw at Digikey, the price difference is minor unless you get something wacky....IOW? No reason not to get a tier 1 capacitor...
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Post by Ex_Vintage on Mar 25, 2021 21:39:59 GMT -5
Electrolytic life is also highly dependent on design derating. Most electrolytic caps are rated at 2000 hours use at rated conditions. Running any electrolytic at or near rating will cause internal heat rise and that combined with poor environmental design (cooling / location) will cause leakage and bulging due to outgassing of the electrolytic material (usually ethylene glycol). Derate current, applied voltage and have them in a cool environment and they will last many years. If you are going through the work to update a treasured piece of equipment, spend the extra few bucks and get quality parts and then keep you electronics cool.
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Post by leonski on Mar 26, 2021 1:40:23 GMT -5
Many 3000 hour caps out there, too. Look at the listing at Digikey......
And there seems to be a differene between 85c and 105c rated....BESIDES the obvious temp rating difference...I dont' know enough to make sense of some of the ratings....
COOL always helps, though, no question....and keeping within part ratings comes under the heading of 'common sense'. Don't use a 1/4 watt resistor where you need 1 watt.....that sort of thing.
I just took a quick look at Digikey. This is just an EXAMPLE......Caps rated for 1000 hours @ 85c. I'd expect a doubling of lifetime or better for every 10c .....OR some such rule of thumb.
And follow Ex-Vintage advice and design conservatively......Stuff run 'to the edge' doesn't last and is far less reliable.
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KeithL
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Post by KeithL on Mar 26, 2021 8:20:51 GMT -5
It's more like 10x the lifetime for every 10 degrees lower temperature on regular electrolytics. (And 105c is really very hot... about 215 degrees Fahrenheit... )
Many 3000 hour caps out there, too. Look at the listing at Digikey...... And there seems to be a differene between 85c and 105c rated....BESIDES the obvious temp rating difference...I dont' know enough to make sense of some of the ratings.... COOL always helps, though, no question....and keeping within part ratings comes under the heading of 'common sense'. Don't use a 1/4 watt resistor where you need 1 watt.....that sort of thing. I just took a quick look at Digikey. This is just an EXAMPLE......Caps rated for 1000 hours @ 85c. I'd expect a doubling of lifetime or better for every 10c .....OR some such rule of thumb. And follow Ex-Vintage advice and design conservatively......Stuff run 'to the edge' doesn't last and is far less reliable. |
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Post by KeithL on Mar 26, 2021 8:47:59 GMT -5
In general, when it comes to electrolytic caps in a power supply, no you are NOT going to hear a difference. And, no, "name brand capacitors" aren't necessarily better just because the name of the manufacturer happens to be familiar to you.
And that goes double for many so-called "audiophile brands"... and obviously "more expensive" doesn't necessarily mean "better". (And a super-expensive part, that works great in a communications satellite, may not be all that good for audio anyway.)
Certain circuit designs require specific types of capacitors in certain locations. For example low-ESR capacitors are required at certain circuit locations in an SMPS. However, that does NOT mean that using over-rated parts in other places will make them last longer, or sound better.
(And, of course, an expensive part won't sound better, or last longer, if it's not right for the job at hand.)
I should also point out that, on many of our amps, the larger caps are stuck down to the board with glue... (It's really to help secure them firmly in place during shipping.) However, while that goop usually starts out clear or pale yellow, it tends to turn brown and sort of nasty looking with extreme age. And, when that happens, a lot of people seem to mistake it for leakage from the capacitor. And, in case you were wondering, slight unevenness in the plastic covering on those big caps really doesn't matter either
I would also add a bit of specific advice about AVOIDING so called "audiophile upgrade parts"... Unless you know exactly what you're doing, it's easy to damage the parts, or the circuit board, when attempting to replace parts.
We've seen many sad cases where a working product was totally destroyed by someone attempting to "upgrade it"... (And a few were perpetrated by expensive "upgrade services" who really just plain didn't know what they were doing.)
I have a XPA-2 gen 1. Recently I need to open it up for service .... while the unit was opened, I notice on the main board, all the big capacitors were of cheap,unknown-chinese name, and seem like some of them started leaking (the amp still function fine). There are many discussions of this issue on this forum for many years now. Anyway, my question is if I replace these cheap Capacitors with HIGHER END, HIGHER QUALITY, brand name, equivalent or better specs/value.... will that improve the sound quality? significantly (can I hear the different)?? Have anybody experience with this?? any input or advice??. Thank you |
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Post by KeithL on Mar 26, 2021 8:59:02 GMT -5
In general almost all capacitors are soldered in place... and, as far as I can recall, that is 100% true in everything we make. This makes them tricky to replace unless you are experienced with soldering and unsoldering components. (Sometimes very large filter caps, especially in older units, may be connected with wires and terminals or with screws alone.)
IF YOU DON'T KNOW WHAT YOU'RE DOING IT'S EASY TO DESTROY THE CIRCUIT BOARD WHEN ATTEMPTING TO UNSOLDER PARTS... IT'S ALSO EASY TO OVERHEAT THE NEW PART, WHICH CAN CAUSE IT TO FAIL OUTRIGHT, OR TO FAIL PREMATURELY...
To be quite blunt...
Soldering isn't all that difficult if you know what you're doing... But it's also quite easy to destroy things with a soldering iron if you don't know what you're doing...
If you have no experience with soldering then changing parts in a working amplifier is NOT a good place to start... (Maybe try a nice kit or two first.... and get yourself a nice temperature-controlled soldering iron and proper solder.  )
Good Question DY! I'd like to see a photo...... If I was the OP, I'd seek a 2nd, professional opinion.... Also? Do they solder to the board, if if so, do you know lead spacing? |
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Post by vcautokid on Mar 26, 2021 12:56:01 GMT -5
Correct, if you don't know what you are doing, you, you maybe doing more harm than good. Understanding proper solder techniques including temperature, duration and so on is vital. You could damage the component in question you are working on, or surrounding components. Not to mention the Vias or circuit traces or pads on the board itself. If you don't know what you are doing, have a professional technician do it for you. Also learning on a kit is an excellent idea. Power amplifiers carry potential lethal voltages and currents and can be very dangerous. If you proceed, you proceed at your own risk. Please be careful.
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Post by nguyenphananh on Mar 26, 2021 13:43:19 GMT -5
Hello everybody, sorry for late reply... I didnt check this post. So to answer some of the question above:
1. Yes, I knew many of the stain on the pcb board were glue, but some of the Caps were already bulging (inspected by repair tech)
2. Following some of the members advice, I already ordered a bunch of new caps and waiting for them to arrive.
3. Like I said earlier, I knew my solder capability... so I will let the tv repair shop replace these for me. In fact, I already dropped off the amp for them to figure out the LEDs meter issue....
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Post by leonski on Mar 26, 2021 15:17:24 GMT -5
In general, when it comes to electrolytic caps in a power supply, no you are NOT going to hear a difference. And, no, "name brand capacitors" aren't necessarily better just because the name of the manufacturer happens to be familiar to you.
And that goes double for many so-called "audiophile brands"... and obviously "more expensive" doesn't necessarily mean "better". (And a super-expensive part, that works great in a communications satellite, may not be all that good for audio anyway.)
Certain circuit designs require specific types of capacitors in certain locations. For example low-ESR capacitors are required at certain circuit locations in an SMPS. However, that does NOT mean that using over-rated parts in other places will make them last longer, or sound better.
(And, of course, an expensive part won't sound better, or last longer, if it's not right for the job at hand.)
I should also point out that, on many of our amps, the larger caps are stuck down to the board with glue... (It's really to help secure them firmly in place during shipping.) However, while that goop usually starts out clear or pale yellow, it tends to turn brown and sort of nasty looking with extreme age. And, when that happens, a lot of people seem to mistake it for leakage from the capacitor. And, in case you were wondering, slight unevenness in the plastic covering on those big caps really doesn't matter either
I would also add a bit of specific advice about AVOIDING so called "audiophile upgrade parts"... Unless you know exactly what you're doing, it's easy to damage the parts, or the circuit board, when attempting to replace parts.
We've seen many sad cases where a working product was totally destroyed by someone attempting to "upgrade it"... (And a few were perpetrated by expensive "upgrade services" who really just plain didn't know what they were doing.)
I have a XPA-2 gen 1. Recently I need to open it up for service .... while the unit was opened, I notice on the main board, all the big capacitors were of cheap,unknown-chinese name, and seem like some of them started leaking (the amp still function fine). There are many discussions of this issue on this forum for many years now. Anyway, my question is if I replace these cheap Capacitors with HIGHER END, HIGHER QUALITY, brand name, equivalent or better specs/value.... will that improve the sound quality? significantly (can I hear the different)?? Have anybody experience with this?? any input or advice??. Thank you I agree in general about audiophile parts. Though in SOME cases, the measureables ARE better. But for PS Caps? TIER 1 is where you want to be. The cost difference is MINISCULE between who-knows-who AND Tier 1. You'll have to educate yourself about some of this stuff, don't rely on ME or even Keith. Tier 1 manufacturers make 'lines' of parts. Usually a 3 letter code or indicator. Sometimes only 2. Again, do some reading. As for 'upgrades'? A good way to destroy the value of a piece of gear. This is so subjective and sometimes simply money driven (maybe greed?) as to be a Massive Red Flag. I would buy a used amp in a heartbeat and HAVE, but only Un Modified. The only gear I ever modded was my old Kenwood. And that has been reversed and it is now 'back to normal'. The OTHER mod I'd do would be to upgrade my speakers. Go to an active crossover and REAL (not passive) BiAmp. But Magnepans are on the exception list. A HUGE body of lore and knowledge exists. Recently while looking at KLIPSCH I discovered an aftermarket company selling crossovers and a few other goodies. A whole slew of aftermarket stands exist and a few (Peter Gunn) will do a total reframe in beautiful solid hardwood....Take your Pick! www.indiespinzone.com/mag/mag4.html |
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