PSU Filter Caps - What Have You Used?

PreCd

I am in the process of replacing the PSU Filter caps in my Adcom GFA-555. What have others used in their power amps? Of course I am looking for low ESR cap. My 555 takes four 15000uf 100v caps.

Interested in hearing what brands others have used for their PSU application and their thoughts on that specific capacitor. What difference did it make?

heiney9

Panasonic FC works really great and won't break the bank.

H9

FTGV

Capacitor design has improved considerably since your 555 was built so virtually anything within reason will have lower ESR.For the purposes of main filter banks I personally don't look for anything exotic prefering to use things like UCC's KMH series or Panasonic TSH.These are good general purpose caps with 105 deg.C rating for a long service life.However these are only available with PC snap mount terminals so you will need to get creative if you want to retrofit them in place of those big cans in your Adcom.

PreCd

heiney9 wrote: »

Panasonic FC works really great and won't break the bank.

H9

Would love to use those but cannot find a 50mmx100mm with screw terminals. Forgot to mention that! I agree that those are good at a good price. I used those on the PCB.

lanchile

I always use Mundorf audio grade caps in all my diy amplifiers. They are excellent caps very low ESR. They are made in Germany. I order them from Parstconnexion.

PreCd

FTGV wrote: »

Capacitor design has improved considerably since your 555 was built so virtually anything within reason will have lower ESR.For the purposes of main filter banks I personally don't look for anything exotic prefering to use things UCC's KMH series or Panasonic TSH.These are good general purpose caps with 105 deg.C rating for a long service life.However these are only available with PC snap mount terminals so you will need to get creative if you want to retrofit them in place of those big cans in your Adcom.

Well said. I have been looking at the ESR ratings for Nichicon Super Through for instance and the Vishay looks better on paper. Plus the Nichicon's are way to big for my cabinet. The Vishays would drop right in but there are some Epcos that rate way better but I would have to drill new holes and do some wiring to get them in.

FTGV

PreCd wrote: »

Would love to use those but cannot find a 50mmx100mm with screw terminals. Forgot to mention that! I agree that those are good at a good price. I used those on the PCB.

Nor would they be available in the large values needed unless you build a custom PC board and parallel a bus load of them.

lanchile

heiney9 wrote: »

Panasonic FC works really great and won't break the bank.

H9

I agreed! these panasonic FC are very good and they are 105c too.

PreCd

lanchile wrote: »

I always use Mundorf audio grade caps in all my diy amplifiers. They are excellent caps very low ESR. They are made in Germany. I order them from Parstconnexion.

I looked for the Mundorfs in the size I need but they do not have them.

PreCd

FTGV wrote: »

Nor would they be available in the large values needed unless you build a custom PC board and parallel a bus load of them.

That can be done! And more of those in parallel would provide more filtering. I am just trying to keep is simple but provide a good degree of filtering at the same time.

Love those FCs though.

lanchile

PreCd wrote: »

I looked for the Mundorfs in the size I need but they do not have them.

Just add 6X10,000uf That will get your 4X15,000uf but way better quality. also you can try the Panasonic FC or the ones that Bryston uses the Nippon KMH 105c. Make sure they are original ones , There are a lot of that are fake ones!!!

FTGV

PreCd wrote: »

That can be done! And more of those in parallel would provide more filtering.

Not to mention paralleling lowers ESR further and multiple smaller caps will have faster charge/ discharge rates which some might say is sonically benificial. I believe the largest FC available in 100volt rating range is under 1000uf so you would need to parallel a few dozen. :cheesygrin:

Love those FCs though.

Yeah I have used them for years in my preamp,dac,active crossover projects.

lanchile

This is from Bryston site! They use just Nippon caps.



FROM ENGINEERING:

Hi James;

Bryston offers a 20-year warranty on our power amplifiers and preamplifiers. For that reason, we do a great deal of research of filter capacitors. We need to be sure they will last longer than the warranty period before needing service.

As with many electronic components, it turns out that the lifetime of electrolytic caps is dependent on temperature, with lifetime cut in half for every 10 degree C increase in operating temperature. Or, to look at it another way, if high temperature electrolytic capacitors are specified, their predicted lifetime doubles for every 10 degree C reduction in operating temperature below their maximum rating. It is for this reason that Bryston uses electrolytic capacitors rated for 105 degrees C minimum. These components are normally specified for 3000-5000 hours of operation at maximum temperature and current. Bryston amplifiers run at approximately 40-45 degrees C average temperature over their operating life. If we subtract 45 degrees C from 105 degrees C, we get 60 Degrees, or doubling lifetime 6 times, equaling a factor of 64 increase in lifetime beyond its 105 degree C specification. 3000 hours X 64 = 192,000 hours, or 22 years of 24-hour-per-day operation, worst-case.

It is very important to recogize exactly what is required to specify and produce a long-life, high-temperature electrolytic capacitor: First, the design must minimize flaws and impurities in all the separate parts of the complete component. Any impurities will lead to unwanted chemical reactions which would contribute to the deterioration, corrosion and degradation of the internal materials, especially as temperature rises, eventually destroying the component. Second, internal electrical connections must be made especially low-resistance, to reduce temperature rise with current-flow, (i.e., ESR must be extremely low, in the low milliOhm range). Third, seals and methods of excluding contaminating influences must be particularly effective and long-lasting to maintain stasis of all internal materials even under brutal conditions. In short, the closer to theoretically 'perfect' design and construction a capacitor is, the longer it lasts, and as importantly, the better it does its job. That means it also sounds better because it more effectively maintains the purity of the musical signal.

There are many 'exotic' capacitor manufacturers making expensive hand-assembled components, but we find that many times they don't stand up to tests of purity and long lifetime. If Bryston finds a better component, based on actual tests of performance and construction that guarantees long lifetime, we use it.

PreCd

lanchile:

Good article. I have read and studied and read and studied on audiophile caps and heard from both sides on the subject. Very interesting and a lot of information to take in.

lanchile

PreCd wrote: »

lanchile:

Good article. I have read and studied and read and studied on audiophile caps and heard from both sides on the subject. Very interesting and a lot of information to take in.

Good for you! it looks like you have done your homework!. make sure you order your caps from a reliable company, since these days even caps are counterfeiting.

PreCd

Done and done. Ordered the Vishays from Digikey along with 3.9kOhm 3W Metal Film resistors which reside on the filter caps at this time. Might as well replace those too.