Question about replacing can capacitors in Seeburg amps

[jeffinmn]

I'm wondering how long can capacitors last. 

Some years ago I recapped a couple of Seeburg Amps. One is the HFMA1-L6 for a V200 and the other is the MRA5-L6 for an HF 100R.

The MRA5-L5 was back in 2004 or so and I was able to get a couple of new old stock Mallory can capacitors with blue printing on them, 40MFD at 450 volts  which replaced two of the existing capacitors on the top of the amp. The other was a 4 section CE Manufacturing capacitor with all 4 sections at 20 MFD at 475 volts. I combined two of the sections to create 40 MFD and used the two 20 MFD sections to replace 2 20MFD sections from the original 4 section can. The 10MFD section was replaced with a 10MFD cap mounted under the chassis. 

I like the amps to look original on top and neat inside on the bottom. 

I also rebuilt the HFMA1-L6 at about the same time but I didn't have any can capacitors.  I was able to install replacement caps underneath and they looked nice. I left the original can capacitors on the chassis. The amp itself seems to have had something spilled on it that won't clean off or the metal is just discolored for some reason, but it works perfectly, just not a nice looking exterior.

Anyway, a very nice, clean amp became available on Ebay that was rebuilt about 3 years ago, and included a nice set of tubes for a fair price so I bought it.  When it arrived I noticed that the filter caps he installed were fine but not installed very neatly. One set was close to the side of the amp and when I installed it one of the pegs that aligns it with the selection receiver was touching the wires from a pair of the replacement caps. Luckily I noticed this and moved them out of the way before turning on the jukebox. This amp also works well and looks almost new. 

I decided to replace the 220k resistor connected to pin 1 of the 5879 tube with a 1 meg ohm resistor to increase the treble, as I posted earlier. I noticed that the chassis mounted caps that were no longer in use were the Mallory brand caps with the blue printing on them. They did not look original, compared to the can caps on my othere HFMA1-L6 since those has information stamped into the metal, with no ink of any kind. I tested the Mallory caps with my Jackson condenser tester and was able to reform them . One measured at 33MFD and the other at 40MFD, working at the listed voltage. They were supposed to both be at 33MFD but I think that it's close enough and the amp works great. One section of the 4 section can was off a good bit so I replaced it with another CE Manufacturing Can capacitor that I got a few years ago. I tested it on my capacitor tester and it works as it should. 

I removed the other filter caps mounted under the chassis since the capacitors on top of the chassis made them unnecessary except for the 10MFD cap that was provided by one section of the original 4 section can. That remains under the chassis. 

The Mallory can caps say made in USA. I know the newest Mallory caps made before they stopped making them say made in Mexico. I really don't know how old they are. Should I have left the under chassis mounted replacement caps in place and not reconnected the Mallory can caps? How long do these Mallory can capacitors last?

[robnyc]

Jeff, I have original Cornell, Sprague and Mallory 'lytics in both commercial (PA)and juke amps in revenue service. The quality of American parts -especially back then (50s-60s) was far better than anything you get today unless it is spec'd for Common Carrier or military use.

I do bi-annual checks for evidence of leakage or envelope heating, year-after-year the old caps hold up. Note that this applies -only- to 'lytic and some couplers such as ceramic and mylar. All paper must be changed.

Contrast that will all the computers, TV's and other recent junk I find thrown out with 'poppers" -leaking, bulged caps.

Then we have the garbage volume pots and encoders that have silicone glop in them that "smooths" the operation but leaks into the contacts and operation erratic or entirely dead in less than a decade. There is often inferior contact metal that is crudely plated to look like copper or gold, but wears off quickly an ruins the control's reliability.

Our landfills are packed with stuff that, had it been made 50 years earlier, would still be working...Capitalism seems to regard quality & durability as a problem now.

RobNYC

[Ron Rich]

Jeff,
I can tell you egg-zact-tley how long yesterday's, or today's production, will last, just as soon as you can explain which came first--Chicken or egg--



Rob,
Once again, we may need to dis-agree here ! 50 years ago many brands of caps, were "el C(r)apo" ! Today, if one searches, and does not buy solely on price, many good, long lasting caps are made by CAPtalist company's that want, strive to, and do, make a great product.

[robnyc]

Mar 4, 2018 14:43:49 GMT Ron Rich said:

Once again, we may need to dis-agree here ! 50 years ago many brands of caps, were "el C(r)apo" ! Today, if one searches, and does not buy solely on price, many good, long lasting caps are made by CAPtalist company's that want, strive to, and do, make a great product.

Ron, there is no excuse for this 'capacitor plague". The caps today deal with far lower voltages and, in general, lower temperatures.

I agree that name brands such as Panasonic do still make good caps, but poor quality caps are still being used on average consumer devices.  This only surfaced about the mid-nineties and now, twenty years later, I still see 2-3 year old devices being tossed due to poppers.

Up till the current degenerate administration there was a move to require that most items sold here be 'repairable" and have extended warranties. This was beginning to force better oversight of component quality by OEMs. Now, that is probably dead and we are back to the 'wild west". 

Once we weakened our consumer laws and allowed the "market" to decide where-how things were to be made, we got what we now have: good designs built with poor components. China is particularly notorious for the practice of making their published median spec's actually be the maximum rating for their products. They also must be watched like a hawk for using lower rated components packaged with inflated spec's.  Someone I know in Thailand who works for Sony told me that many of these producers will sneakily change to lower component quality during a production run just to squeeze and extra 0.02 cents profit on each assembled one sold.

There is no good reason why an electrolytic cap made 50-60 years ago, outlasts one made 5 years ago.

This is just a gripe, not aimed at you personally.

Rob

[jeffinmn]

Thanks for your input, I like a good debate. What I think you are both saying is that quality parts last longer. I believe Sprague and Mallory made quality capacitors. When an old can capacitor such as Mallory, are reformed, do they continue to operate properly? What if they are left unused again for some months? I reformed some new old stock Mallory caps this weekend that sat for several years on the shelf. They test great now but how will they test in a few months after sitting unused?

I'm wondering if you guys use CE Manufacturing can capacitors and what you think of them. They advertise that they make their caps using equipment purchased from Mallory. I have one of their 4 section caps in one of my Seeburg amps and it works fine, but it's only been in use for about 10 years or so.

[robnyc]

Jeff, in my experience those old caps are fine after initial reforming. I have amps in my locations using original lytic's from the 1950's. they are used daily.

Periodically, I check for heating or boilout. I'll occasionally inject a 60Hz tone and check for excessive ripple on the filters at average levels. This is ideally done with a scope, but the AC scale on a DVM will give an adequate idea if the caps have lost capacitance. Note that in the older electrolytic's actual capacitance was often well over the rated value so slight losses are not of consequence and won't show up.

RobNYC

[edison]

I looked at CE Distribution on line. Could not find can capacitors used for an M100C amp. While I have taken into account both sides of the debate (leave them in or replace) at this point I am looking to purchase new correct cans out of speculation correct cans will not exist much longer. I mean how many more years will plug and play part exist? I hear Victory Glass is out of business

[Ron Rich]

Hi Edison,
Well, whut can I said ?? Cans have been in very short supply for years-- that being said, many people just use either axial, or radial caps and hide them under the chassis, leaving the old (DIS-CONNECTED!!) caps, in place for "looks".
IF, you would READ the FAQ's here, every once in awhile, you would know that Victory Glass is NOT "going out of business"-- In fact, it is undergoing a whole new "re-birth", under new ownership. I expect that very soon, you will see products that have not been available for years, return to their catalog ! Ron Rich

[edison]

Sorry Ron, I don't get on to this enough. Great news on Victory Glass

[Ron Rich]

Hi Edison,
Well, why not ?? LOL-- Ron Rich

[bklossner]

Why reform old electrolytic caps? They're just going to leak again. New electrolytics have a smaller footprint and only cost a couple of bucks via a trusted distributor.

Yes, there's a problem with counterfeit capacitors in the market right now but if you do some research, you'll feel better. I have found that Rubycon caps are incredibly reliable. (Again, purchased through a trusted provider. Not eBay or Amazon).

And, yeah, regarding wax caps, they all must be replaced because they're basically resistors now.

[edison]

Thanks Ron. Is there any way you hear when the "lytic caps begin to atrophy or do they just just go bad all at once like a lightbulb would? The loud humming noise is what I am getting at when they go bad.

[Ron Rich]

Hi Edison,
No way to tell-- my crystal ball quit working years ago-- How much longer can I last-- not much !
Ron Rich

[edison]

Fair enough. The majority of the people that work on amps around me claim the the 'lytics need to be addressed within a full re cap. Many go after the selenium as well....thoughts?

[Ron Rich]

Hi Edison,
As far as I'm concerned-- yes on the lytics-- they are old--like me-- on the selenium's-- depends-- on the open frame type, if the paint looks good, & the output is within spec., I don't change them-- Ron Rich