Power supply cap brands & Specs

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I am comparing some specs for some new Power supply caps i need for my Classe DR-15 amp. I am restricted to a 2" x 4-1/8" size. I found that there are quite a few choices actually, Most are pretty close to the same spec so i am wondering. given the choice. what is more important.

Cornell Dublier has the best selection. But United Chemcon has one that is bigger, yet cheaper. Specs look pretty good but what is the thought about there quality?

I believe N.P. mentioned he likes CDE, i take that with merit. But are the U.C caps no good?

The stock caps are Classe Labeled, 20,000uf 70vdc 85 Deg units.



Here are the basic models i am considering replacing them with.

CDE:

21,000uf 75Vdc 105 Deg ESR 11 ripple 11.5
25,000uf 75Vdc 95 Deg ESR 15.6 Ripple 14.4
30,000uf 75Vdc 85deg ESR 15.6 Ripple 12.1

46,000uf 75Vdc 85 deg ESR 12.1 Ripple 15.5 (2" x 5-5/8" Might work)

United Chemcon
27,000uf 80Vdc 85deg ESR 9.8 Ripple 12.39 (Best priced!)


So out of those specs, what do you guys think?

Prices range fro $19 each to $55 each so there is quite a gap.

With the CDE the specs are all pretty close. close enough that i would think it wouldnt matter. all except the last one with is a 1/2" taller but i might be able to squeeze that in there. But is it worth the extra effort? I would be doubling+ the capacitance over stock

The U.C is the cheapest. but that low ESR number is interesting. The rated voltage is 10v higher then stock and the +/- tolorance matches stock.

So is it worth an extra $30.00 per cap to double in size. or should i be more concerned with Temp or ESR. or are these specs so close it just doesnt matter?

Thoughts on UC VS. CDE??


Zc
 
Member
Joined 2002
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This is a good question...

When I buy caps I always try and get them at the 105 Deg C

I don't pay to much attention to the Ripple or ESR, I also
care about the price so I can pass that price on to my
customers

Certain values I will still buy at 85 Deg C but at a lower
cost...

I'm interested in other comments on the ESR and Ripple
Does it really matter in solid state amps.

Steve @ Apex Jr.
 
it makes a huge difference in fine detail and transient control.

This is the very framework by which the ear 'hears'. So yes, esr, and esl are both as critical as ripple current. As a rule, the longer the cap the better, espeically if it is slit foil, but there is only one manufacturer of slit foil electrolytics, and that is out of the UK, IIRC.

If these capacitors do not have to be screw teminal types, then Digikey's panasonic 4 pin snap mounts are the some of the best ripple current rated caps out there.

I think they have some pretty wildly spec'ed 2"x4" 70-75 volt caps.

Last time I checked, which was quite some time back, Classe's caps were custom labeled mallory caps, made by the Duracap people. They might be making the cde's as well. This is a good opportunity to check the ripple rating. Find the equivalent classe' cap in the mallory listings. You may find it very tough to beat the overall specs on the mallory caps, current delivery wise.

http://www.duracap.com/

The Duracap site has the mallory cap listings/info. I'm interested in their welding caps. That's just gotta be good........

Let's take a look see for the panasonic caps:

page 1192 in the current digikey catalouge. 50x105mm, same size you are looking at. Are you sure you need screw terminal, or not?

39,000uf, 80VDC, 14.34 A ripple at 120hz, 16.49A ripple at 10khz-100khz, and the ripple multiplier says..well..none is listed on these pages. Let's see what panasonic says.

http://www.panasonic.com/industrial/components/pdf/pic_t-up_series_dne.pdf

Panasonic says multiply by 1.5 at 45 degrees celsius, which is right about where you will be. so, that's 21.51A at 120hz, and 24.75A at 10khz-100khz. with an esr of 0.013ohm at 120hz,and 0.010 at 10khz.

Digikey has them at $30 each.

Beat that. The mallory's have a tough road to hoe to beat that.
I like the panasonics. They are good. Excellent selection as well.

I just checked the manufacturing date of 1992, that is definitely a mallory cap. Low capacitance, high ripple current.

This means, solid transient, but no follow up of sustained current delivery. so, good transient resposnse but no body to the tune or the bass. Very brystonish in overall sound quality, I'd wager. no small wonder, they both used the same supplier for their caps.

I'd say ANYONE's capacitors are going to make an improvement in the amp's bass stability and overall presentation, as the amp is likely to suffer from bass control, with such a low capacitance value. Some disagree, but after over 20 years of doing this exact sort of experiment, I'd beg to differ. whatta yah expect from folks who listen to speakers that have holes in their boxes. :p ;)
 
UNfortunatly i do need screw tops. I have a bag of new 15,000uf 80v snap in caps on hand. but they are much smaller and i dont want to redo the whole cap board. I would like to keep the major parts of the amp as stock as possible, but upgrade the parts that fit if i can.

So looking at screw type caps. what do you think of the models i have listed. Dont i want a lower ESR number?

The CDE caps range from double to triple the price of the United Chemcon. I dont mind spending the money as long as there is a substantial difference to be had. or if the UC.s are just bad quality or something.

The big 47,000 caps are three times the price, but is there sufficient benifit to go through the trouble of trying to fit them in, over say the 30,000uf CDE's?

I can order stock units, but i want to go with the best i can within reason.


good info on the duracaps. that is what i have! same red casing and these state type as EAP which i find on the website. there doesnt seem to be any specs listed for any of there caps there however. i will give them a call in the morning.
 
KBK said:
whatta yah expect from folks who listen to speakers that have holes in their boxes. :p ;)

hahahahah now that is funny. I will be using this amp with a pair of Revelation 3 speakers. These are sealed boxes. nad funny thing is in an interview with Paul Hales he makes a comment about how speaker designers spend all this time to make there cabinest stiff and nonresonant, and then they go and design a big one by adding a port. never made sense to him and after reading that, me either!
 
I'd be tempted to go to the united chemicon caps,and then upgrade the rectifiers, as the transient current draw is going to be increased, at turn on. Depends on what rectifiers you have in there now.

Look at the mallory listings for near equivalents of the capacitance and ripple ratings for the caps you have now. go for the 85 degree caps, as the ones you have are unlikely to be 105's. Note how low the capacitance values are, and how high the ripple ratings are. However, classe can order anything they want, so they may be different. but I doubt it.
 
Zero Cool said:



These have part number EAP203U070V4C 3PH

so, they use the same number system as a mallory cap.

a 20,000uf capacitor, 70 volt rating, in a 4C size package. I think, on the last bit. the 3PH part is a bit off. A look at the mallory numbering systems will explain it better.

That sounds custom (I guess I was wrong!), and an older design. You'll have to track down an older mallory catalouge for the ripple ratings.

I think the H means it has 'high' terminals.
 
I just checked and i can fit the 4-5/8" 47,000uf units in there without too much trouble. it is tight but if i add an extra pad below the transformer it won't be tight at all.

But again is going from 27,000 to 47,000uf worth the price difference between the U.C's at $18.58 each and $56.09 each for the big CDE's?

Hmmm decisions, decisions.
 
I like the CDE's. And I ALWAYS buy the bigger gun.

mo'better'bass!

Otherwise, why bother?

I've got ~300kuf in my Belles 450.......

The felsic-safco's I have in there, are 47kuf-100V, and rated at 22A ripple current. Without any temperature multipliers, either. Add that in, and they are around 40A ripple at their usual operating temp. Ouch.

They were NOS closeouts at the original Sonic Frontiers when they stopped doing NOS stuff, the first time around, back in about 1996 or so.

You may have a difficult time exceeding the quality of the caps that are already in there. Mallory has wicked ripple ratings. Call duracap, they may share the info on the caps, but they may not. Instead, they may send you a PDF of old mallory cap listings, which is the same thing, but does not voilate the client/company aspect of their relationship with classe.

The only reason I found out, was that I was looking at getting some custom caps made and I told them, "what if the caps needed to have a name like 'classe' on the side of them, would you do that?"

"Funny thing", the Sales guy says,.."we are making those caps already."

Otherwise, I never would have known.
 
I spoke with Duracap today. they were very nice. told me they no longer supply Classe as they are now made oversea's! that was interesting and they said they sold some caps to N.P. this year! that was also interesting.

They are going to look up the spec's on the caps i have and email me the details. they dont stock any caps so they couldnt help me with replacements but they were very willing to build me custom caps if i needed them! we did speak about another project and i may be in touch with them again. but i think i am just going to go with the big CDE's for the classe.

there is a slight discount if i buy 10 or more, i need 4, anybody else what to get in on some???


Zc
 
shh. yes, I think I might have turned NP onto duracap about 6-8 months ago. I told him that he may as well buy from the source. And I still need to approach duracap about a custom project, with custom electrolyte and foils. My personal ideas on a BG replacement, as they have ceased production, so all bets and holds are off. At that point, no shame on leveraging the work into something else....

I have people I can go to in China, directly, with this. Big problem though. I'm not sure anyone in China can keep any secrets, no matter what has been signed by anyone. The paper carries no weight, so it should be ovious why that is. Makes the russians seem honest at times.
 
Try ampohm in the UK, they can also do custom caps, chokes etc... Contracts probably count for a bit more in t he UK.

I have used some of there polyprop caps, and they are first rate... not only in performance, but even the package had a onepiece durable plastic protection sleeve.. only the copper tips for soldering are exopsed... looks watertight. and 5% rateing at very low prices relatively speaking.

http://www.ampohm.co.uk/

Ampohm Wound Products Ltd announces recent endeavours to assist automotive company in China have paid off

Ampohm Wound Products Ltd announces recent endeavours to assist automotive company in China have paid off.

Based in Launceston, Cornwall, Ampohm, which is part of the GSPK group of companies, has forged a new trading relationship with a significant automotive manufacturer located in the Shenzhen area of China. Manufacturing and supplying volume orders of two bespoke parts, Ampohm have customised a 1µF capacitor and a specially coated inductor to meet the specific needs of the automotive manufacturer.

This particular customer is just the latest in a long line of major global manufacturers placing orders with Ampohm since the introduction of their new website – www.ampohm.co.uk

Ampohm’s success is thanks to their impeccable reputation within industry for service and quality, providing custom made and bespoke assemblies to meet varying requirements across a variety of industries.

Rob Johnston, Director of Ampohm Wound Products Ltd commented – “We are all aware of the en-masse migration of manufacturing to low cost regions, and subsequently this is typically followed by the buyers. We at Ampohm are extremely pleased to have been in a position to quote and win business from a significant Chinese customer. The satisfaction is made greater when we know the factors that influenced the decision were quality and reliability.”
 
Well as it turns out the catalog page i was looking at had a typo that 46,000uf unit is 5-5/8 and not 4-5/8 so those will not fit.

I am going to have to go with the 30,000uf units, but even still thats 10K more uf then stock and they are cheaper too at $38.69 each. I think i am going to try and see if there is any interest in a group buy as the price drops to $34.89 each and 4 bucks is well 4 bucks.


Zc
 
Bill from Duracap emailed me the specs for the Classe caps today.

capacitance -----------20,000uf
voltage ----------- 70 vdc
surge V ----------- 90 vdc
dc leakage ----------- 6.0 ma
ESR -----------.022 ohm

dia -----------2.000 in.
length -----------4.125 in.

terminals -----------10-32 HP


Now that ESR # does not look like the specs i have been looking at. I need to dig up that catalog page and see what the specs are for the CDE caps i have been reviewing and see how that spec compares.


Zc
 
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