Forgive me for not reading the 90+ pages of the "Best Caps" thread, but after going through a fair bit of it, nearly all the discussion seems to be devoted to smaller capacitors. I am getting ready to change out the original (26 year old) filter caps in my Adcom GFA555 II power amp, which are 15,000 mf at 100 volts). The vast majority of electrolytics recommended for audio use aren't available in such large sizes, so I'm asking advice on these "big boys".
After researching some of the common sources, e.g., Mouser, I am considering several different options. First would be the Nichicon LNR series, which is a can-type with screw connectors. The one I need is a bit undersized so I would have to make a few physical modifications to mount them. It's got a ripple current of 6 amps with no ESR listed. They cost about $34 bucks each and I need four of them.
I could go with the same capacitor but in a higher voltage version (160 volts) which doubles the ripple current to 12 amps and has the advantage of fitting perfectly in the old holders. (Note that this amp has some hardware that mounts to the top of each cap so not only do I want to match the cap diameter, matching the lead spacing is desirable, too.) This cap is a fair bit more expensive at $58 dollars each.
A road less traveled might be the Epcos/TDK B41560 series which lists a huge ripple current of 30 amps and an ESR of only 10 mOhms. It fits fairly well in the chassis. Its also expensive, coming in at about $53.
Finally, an even less traveled path leads me to the Kemet PEH series that has a ripple current of over 17 amps and an ESR of 17 mOhms. Another appealing feature is the claimed extended life of 12,000 hours. The Kemet fits poorly and costs $44.
This is where I'm at right now. I'm sure there are some other options out there, and I would be interested in hearing thoughts and opinions on all of this. Or if this has been covered recently, feel free to just point me to that thread.
After researching some of the common sources, e.g., Mouser, I am considering several different options. First would be the Nichicon LNR series, which is a can-type with screw connectors. The one I need is a bit undersized so I would have to make a few physical modifications to mount them. It's got a ripple current of 6 amps with no ESR listed. They cost about $34 bucks each and I need four of them.
I could go with the same capacitor but in a higher voltage version (160 volts) which doubles the ripple current to 12 amps and has the advantage of fitting perfectly in the old holders. (Note that this amp has some hardware that mounts to the top of each cap so not only do I want to match the cap diameter, matching the lead spacing is desirable, too.) This cap is a fair bit more expensive at $58 dollars each.
A road less traveled might be the Epcos/TDK B41560 series which lists a huge ripple current of 30 amps and an ESR of only 10 mOhms. It fits fairly well in the chassis. Its also expensive, coming in at about $53.
Finally, an even less traveled path leads me to the Kemet PEH series that has a ripple current of over 17 amps and an ESR of 17 mOhms. Another appealing feature is the claimed extended life of 12,000 hours. The Kemet fits poorly and costs $44.
This is where I'm at right now. I'm sure there are some other options out there, and I would be interested in hearing thoughts and opinions on all of this. Or if this has been covered recently, feel free to just point me to that thread.
Amortize the cost of the components, over a five year "lifespan" of the Adcom. It's just a few dollars per month. But the value of your ENJOYMENT is tremendous. Gigantic. Possibly infinite.
With that in mind, I recommend you stop worrying and simply purchase all of your top three candidates. Install them one by one, and listen to the resulting amplifier in each case. If you like one capacitor type more than the other two, boom, decision made. If you like all three equally well, that is a surprising revelation too, is it not? Pick the one that cost the most, or that was manufactured in a factory farthest from your home ("no man is a prophet in his home town"), or whose exterior paint job is sexiest. Who cares, you are indifferent.
With that in mind, I recommend you stop worrying and simply purchase all of your top three candidates. Install them one by one, and listen to the resulting amplifier in each case. If you like one capacitor type more than the other two, boom, decision made. If you like all three equally well, that is a surprising revelation too, is it not? Pick the one that cost the most, or that was manufactured in a factory farthest from your home ("no man is a prophet in his home town"), or whose exterior paint job is sexiest. Who cares, you are indifferent.
Filter Cap Operating Life
To get the longest operating life from a large power supply filter cap, what is the relative importance of each of these parameters?
Using an equivalent cap with higher voltage rating;
Using a cap with a longer "stated" life;
Using a cap rated at 105C instead of 85C?
To get the longest operating life from a large power supply filter cap, what is the relative importance of each of these parameters?
Using an equivalent cap with higher voltage rating;
Using a cap with a longer "stated" life;
Using a cap rated at 105C instead of 85C?
I would say keeping the temperatures downs to sensible levels whatever cap is used (use 105C if you can get it in the size you want) and most important of all, choose a cap with a ripple rating far in excess of what the part will see in use.
Voltage rating would be way down my list as long as it was suitably chosen. For example I'd be happy with 63 volt parts seeing up to at least 56 volts in use.
Voltage rating would be way down my list as long as it was suitably chosen. For example I'd be happy with 63 volt parts seeing up to at least 56 volts in use.
It's against the Rules to start multiple threads on the same/similar topics, your threads have been merged.
nichicon_kg
15000uF / 100VDC, KG Series, Gold Tune, 63mmD x 80mmH, Solder Lug, Each $49.95
Ripple current 8.7A
15000uf-100v-sikorel-105
Price works out to about US$25ea
7~13mR 38A@100Hz-85°C
Search sikorel to find more info about use in audio
regards
james
15000uF / 100VDC, KG Series, Gold Tune, 63mmD x 80mmH, Solder Lug, Each $49.95
Ripple current 8.7A
15000uf-100v-sikorel-105
Price works out to about US$25ea
7~13mR 38A@100Hz-85°C
Search sikorel to find more info about use in audio
regards
james
Thanks, James. This is for an Adcom GFA555 II which has hardware mounted on top of the caps, so adapting to a lug type like the KG series would pose a problem. After a first pass on the Sikorels, I see the same issue.
Any preferences among the ones I listed in the original post, or do you believe like some that the amplifier's sound is unaffected by the filter caps?
BTW, my search for the Sikorel suggests that it is tied to Epcos which is tied to TDK. Does anyone know what the business connections are for these caps?
Any preferences among the ones I listed in the original post, or do you believe like some that the amplifier's sound is unaffected by the filter caps?
BTW, my search for the Sikorel suggests that it is tied to Epcos which is tied to TDK. Does anyone know what the business connections are for these caps?
Sikorels were siemens and are now part of the epcos/tdk group, he one in the link are M5 screw terminals 28.5mm between centres
B41550 data sheet
The main difference i can see between the B41560 & 41550 is the 41550 are higher reliability and longer shelf life
_____________B41560____B41550
ESR min/max__5.0/10mR __7.0/13mR
Zmax 10k____ 10mR______11mR
Ripple I 100Hz
40degC_______45________40
85degC_______30________36
105degC______15________18
When I have changed the main filter caps it has totally changed the character of the amp, i think it has a lot to do with ringing in the transformer and the way the caps effect the diodes etc
see simple-math-transformer-snubber-using-quasimodo-test-jig
regards
james
B41550 data sheet
The main difference i can see between the B41560 & 41550 is the 41550 are higher reliability and longer shelf life
_____________B41560____B41550
ESR min/max__5.0/10mR __7.0/13mR
Zmax 10k____ 10mR______11mR
Ripple I 100Hz
40degC_______45________40
85degC_______30________36
105degC______15________18
When I have changed the main filter caps it has totally changed the character of the amp, i think it has a lot to do with ringing in the transformer and the way the caps effect the diodes etc
see simple-math-transformer-snubber-using-quasimodo-test-jig
regards
james
If you are looking for the best, I would tend to agree that the B41550 either are, or are very close. Not exactly cheap, but very effective, probably the highest current rating I have seen anyways, and are for "highly professional power supplies". That would lead me to think that the connections are well done, and have some redundancy built in somehow, maybe multiple smaller capacitor windings in one case maybe, haven't cut one apart.
They do have screw-on connections, in case you missed that part...
They sound great to me.
They do have screw-on connections, in case you missed that part...
They sound great to me.
The KEMET and EPCOS items have far superior ratings for PSU applications compared to the Japanese options.
However, if you're comparing specs, make sure you browse the datasheets individually and compare both ripple values and ESR at the same operating frequency and temperature. You'll find that mouser/digikey/RS just quote an arbitrary number for those values - as they are often provided at multiple frequencies and temperatures. If you compare the easy way you'll potentially draw incorrect conclusions, so check the datasheet columns carefully.
It sounds like physical fit is a concern for you, so first isolate everything that won't fit. Then pick the option with the highest ripple current and lowest ESR that you can afford, of the items that will fit. I would prioritise all those factors (first) over the temperature rating.
However, if you're comparing specs, make sure you browse the datasheets individually and compare both ripple values and ESR at the same operating frequency and temperature. You'll find that mouser/digikey/RS just quote an arbitrary number for those values - as they are often provided at multiple frequencies and temperatures. If you compare the easy way you'll potentially draw incorrect conclusions, so check the datasheet columns carefully.
It sounds like physical fit is a concern for you, so first isolate everything that won't fit. Then pick the option with the highest ripple current and lowest ESR that you can afford, of the items that will fit. I would prioritise all those factors (first) over the temperature rating.
The originals do look like CDEs
CDE 15kuF 100V
...................................................ESR...... Ripple
..................................................120Hz... 85ºC
..................................................(Ω)....... (A)RMS... Dia x Len (in)
15,000...CGS153U100V4C.... 0.036..... 7.3 ........... 2.000 x 4.125
15,000...CGS153U100W5L.... 0.043..... 8.6 ........... 2.500 x 5.625
15,000...CGS153U100X4C.... 0.051..... 7.9 ........... 3.000 x 4.125
Solid State Power Amplifier Supply Part 3 has some opinions on caps about half way down
CDE 15kuF 100V
...................................................ESR...... Ripple
..................................................120Hz... 85ºC
..................................................(Ω)....... (A)RMS... Dia x Len (in)
15,000...CGS153U100V4C.... 0.036..... 7.3 ........... 2.000 x 4.125
15,000...CGS153U100W5L.... 0.043..... 8.6 ........... 2.500 x 5.625
15,000...CGS153U100X4C.... 0.051..... 7.9 ........... 3.000 x 4.125
Solid State Power Amplifier Supply Part 3 has some opinions on caps about half way down
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