DuraCap Capacitors

[Classe DR-9]

Good morning folks,

I have two Classe Audio DR-9 amplifiers that have issues and one of the things that I want to do is replace all electrolytics.

The eight big caps are original and marked Classe EAP353U070W4C3PH which after much online research appear to possibly be Mallory now DuraCap in Canada. (DuraCap - Home)

Would the current DuraCap still be the same quality as the originals... would these be a recommended replacement?

From DuraCaps site:

EAP = Extreme Application Power
353 = 35,000 microfarads
U = -10/+75%
070 = 70 Volt
W4C = 2.5 x 4.125 (63.5mm x 105mm) screw type 1.125 (28.6mm) spacing
3 = Single layer PVC sleeve .008 thick
P = Polar
H = High Post

All of this appears to match what is currently in both amps but they do not show them in their datasheet anymore so before I called for availablity I figured someone here might have some feedback.

Thanks!

 

[AndrewT]

I suggest you switch on and measure the ripple voltage on the smoothing banks before you do anything else.
A stereo amplifier will have at least two polarities and a dual mono will have four polarities which you can compare.
If any one is noticeably different from the rest, you may have a problem that is worth investigating.

Try comparing ripple when idling and when reproducing a sinewave test signal.

 

[Classe DR-9]

Hi Andrew,

I’m just trying to source parts right now. I’m replacing all of the electrolytics because they’re approaching 30 years old. My problem is finding PS caps with the right dimensions and specs, I emailed Classe and have not gotten a response but I heard they closed their doors in Canada so that may never happen.

I was able to decode the numbers on the PS caps on DuraCap’s site but I’m not sure of that companie’s parts as I had never heard of them before though they claimed to have had something to do with Mallory at some point but so did Cornell Dubilier. (I think)

Bruce

 

[AndrewT]

Don't change them just because they are 30 years old.
Measure the ripple before you do anything else.

 

[Andersonix]

I have two Classe Audio DR-9 amplifiers that have issues (snip)

You have two amps that both have issues? What are these issues?
I agree with AndrewT that you need to share some baseline PS voltages to get better help.

Today's caps are going to have more C in the same size can, so take advantage of that, and buy the most C in the original's exact physical package.
70V is not even a standard choice these days, but maybe you can get by with 63V caps? Otherwise you would be forced into 75V or 80V caps.

I used the Mouser search filtering to narrow down your dimensional requirements and came up with a 45mF 75V cap for about $67 each (ouch!):
DCMX453U075CC2B Cornell Dubilier - CDE | Mouser

 

[Classe DR-9]

Sorry, been trying to get a response from Classe but since my original post I read that they may have closed their doors in Canada. I have very very little in the way of a schematic for these amps, only what was on their site.

Amp 1’s DC protect circuit relay is not closing and amp two has crackling and snapping in one channel.

I’ve had both for many years (one since almost new).

I’ve got a DR-6 Preamp that’ll probably need attention too.

All are absolutely mint and never been touched other than bias adjustments.

Andrew: We had a hurricane come through a few months back and I stored all of my test equipment and haven’t set it all back up yet, I was trying to do some research first.

Andersonix: If you think those are expensive... I figure based on current research that PS caps similar to what’s in the amp will run about $150 each so that’s $1,200 for both amps.

 

[Classe DR-9]

You have two amps that both have issues? What are these issues?
I agree with AndrewT that you need to share some baseline PS voltages to get better help.
101C353U075CC2B Cornell Dubilier - CDE | Mouser
Today's caps are going to have more C in the same size can, so take advantage of that, and buy the most C in the original's exact physical package.
70V is not even a standard choice these days, but maybe you can get by with 63V caps? Otherwise you would be forced into 75V or 80V caps.

I used the Mouser search filtering to narrow down your dimensional requirements and came up with a 45mF 75V cap for about $67 each (ouch!):
DCMX453U075CC2B Cornell Dubilier - CDE | Mouser

Mouser also has what I was looking at cheaper than the $150 each but not much and a 14 week lead time. $940.80 plus shipping for eight ($117.60 each)

101C353U075CC2B Cornell Dubilier - CDE | Mouser

 

[Classe DR-9]

Mouser also has what I was looking at cheaper than the $150 each but not much and a 14 week lead time. $940.80 plus shipping for eight ($117.60 each)

101C353U075CC2B Cornell Dubilier - CDE | Mouser

Or these at about half the price: DCMX363U075CC2B Cornell Dubilier - CDE | Mouser

 

[egoo59]

Hi Bruce,

I have just completed replacing the original EAP main caps in my pair of Classe DR-8 amplifiers. Original caps were 20000MFD 50v and I have replaced them with Kendeil (K01063223) 22000uf 63v caps which are the same dimensions.

Maybe worth looking at the Kendeil range of caps if they are available in US?

By the way the amps sound a lot cleaner after the recap so well worth the effort.

Good luck with your search for replacements.

Erik

 

[Classe DR-9]

Hi Bruce,

I have just completed replacing the original EAP main caps in my pair of Classe DR-8 amplifiers. Original caps were 20000MFD 50v and I have replaced them with Kendeil (K01063223) 22000uf 63v caps which are the same dimensions.

Maybe worth looking at the Kendeil range of caps if they are available in US?

By the way the amps sound a lot cleaner after the recap so well worth the effort.

Good luck with your search for replacements.

Erik

Thanks Erik,

I’m waiting for B&W (Classe parent company) to contact me, they said they’d get back to me in two days. I haven’t had the time to do proper troubleshooting yet, I still need to check ripple and decide whether or not to risk leaving the old PS caps alone.

Bruce

 

[cbdb]

Neither of those issues sounds like a PS problem. You might want to fix the issues before you upgrade.

 

[Classe DR-9]

Neither of those issues sounds like a PS problem. You might want to fix the issues before you upgrade.

I agree, I’m just trying to get a line on all the parts that I might need before I take them apart for anything. I only want to disassemble them one time.