Forums :: Resources :: Features :: Photo Gallery :: Vintage Radio Shows :: Archives :: Books
Support This Site: Contributors :: Advertise


It is currently Sep Sun 21, 2014 9:09 pm


All times are UTC [ DST ]



Post New Topic Post Reply  [ 17 posts ] 
Author Message
 Post subject: EL MENCO capacitors @600 volts .1- .001
PostPosted: Jun Sun 14, 2009 7:55 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 129
Location: Roslyn Heights
Hi all I have this question on these capacitors that come up on E bay all the time.
"ELMENCO STEATITE PAPER TUBULARS BY PASS CAPACITOR"
@600 volts
This is the brand I am asking on.
I've seen some go as hi as 75.00 dollars for 50 or so.
Will I went for some and found many were leaky or not close to their value.
Do you just use the good ones and hope for the best because there is a tonal value in the good ones?
Ok with this why do so many of these caps sell on E bay.
Are there places in a circuit that there is an advantage to using these caps, even though they are leaky or out of value.????

I like to re-store tube radios back to life and build tube guitar amplifiers.
The early Fender type.
I know these early amps used these caps but why use them if they are leaky. ???
I know there are tone changes with different brands and oil and paper type, well you know all the views on this...
Is there a limit as to how much they may be leaky?
I've read any thing above .2 or 1 volt should be replaced.
There have been different views as to what is good or bad.
Are there any views out there on this, would love the hear back on this.
Regards
Jim


Top
 Profile  
 
 Post subject:
PostPosted: Jun Sun 14, 2009 8:16 pm 
Silent Key

Joined: Jan Thu 01, 1970 1:00 am
Posts: 34328
Location: Sandpoint, IDAHO 83864
To me, they are in the same class as the Micamold paper capacitors. A time bomb waiting for a chance to go off. They may be leaky now and that could not be too much of a problem as a bypass capacitor for a while, but this leakage will cause internal heating.

And as the capacitor heats up internally, the leakage will increase. What you are reading with the capacitor cold may only be a fraction of its internal leakage when the insides of it gets warmed up a bit.

When this internal heating gets sufficient, the capacitor could break down and short out. That is when it gets bad, as it can take tubes and resistors along with it when it goes, and even a power transformer if it is a bypass capacitor across the main B+ in a set.

Capacitors are meant to be be capacitors, not resistors. How long they will last in this leaky state is anyone's guess. It is strictly up to you if you want to continue using them. But for me, they would come out, especially if it was on a set that was going to be used by someone else. Just too much of a risk involved to make me feel comfortable.
Curt

_________________
Curt, N7AH
(Connoisseur of the cold 807) CW forever!


Top
 Profile  
 
 Post subject:
PostPosted: Jun Sun 14, 2009 9:05 pm 
Moderator

Joined: Jan Thu 01, 1970 1:00 am
Posts: 21210
Location: Detroit, MI USA
Leaky caps are just that, leaky caps. Some people choose to pay ridiculous prices for parts that most people would throw in the trash.

In my opinion and that of most experienced professional technicians, paper caps that old are totally useless regardless of whether or not they were originally used in a certain brand of amplifier. They are also potentially dangerous in some circuit positions like coupling caps or bypass caps where significant voltage is across the cap.

There are some applications where a leaky cap can do very little harm if it fails, like a tone control in a guitar, or as a very low voltage cathode bypass. But as coupling caps in an audio amplifier, why risk the probability they can get even leakier or throw off the bias destroying expensive tubes and transformers?? Totally not worth the risk.

Sorry, but I just do not believe in the possibility that a capacitor has a "sound" and I have built literally dozens and dozens of high fidelity amplifiers over the years, and also used to build amplifiers for local bands back when I was in high school and college in the 60's and 70's. I used a variety of capacitor brands, most often the red printed Sprague mylar type or the brown dipped El Menco type, as well as real Sprague Orange Drops and the blue and brown Mallory types. Never heard a bit of difference with any of them.

One of the local guys runs a pair of very expensive chrome plated amps from the 50's and is insistant on keeping the original striped bumblebee caps in it because of the appearance, and he believes they will ruin the sound if replaced with anything else because that is what he read on the internet. I have warned him repeatedly about monitoring the power transformer temperature and watching for glowing elements in the tubes. Everytime I visit there, one of the first things I do is feel the transformers, because one of the amps runs considerably warmer than the other does.

_________________
Dennis

Experience is what you gain when the results aren't what you were expecting.


Last edited by Mr. Detrola on Jun Sun 14, 2009 9:09 pm, edited 1 time in total.

Top
 Profile  
 
 Post subject:
PostPosted: Jun Sun 14, 2009 9:08 pm 
Silent Key

Joined: Jan Tue 16, 2007 11:48 pm
Posts: 9664
Location: Hueytown, AL
Agree with Curt. There is no explaining the audiophile. No capacitor was ever designed professionally into a circuit for its leakage that I know of. And my impression is that guitar amps often distort intentionally but the caps weren't picked for their leakage to do this. Purely a "cult" thing.


Top
 Profile  
 
 Post subject:
PostPosted: Jun Sun 14, 2009 9:35 pm 
Moderator

Joined: Jan Thu 01, 1970 1:00 am
Posts: 21210
Location: Detroit, MI USA
Exactly. None of those capacitors was leaky when originally used in production. They only degraded over the years. So there can be no possibility they were originally chosen for sound quality reasons.

You can be nearly 100% certain the bean counters were responsible for choosing a capacitor brand which was reasonably priced and readily available in quantities needed.

Only in the case of very high end equipment would the engineers even have a chance of specifying a brand name for the parts used and having it approved.

_________________
Dennis

Experience is what you gain when the results aren't what you were expecting.


Top
 Profile  
 
 Post subject:
PostPosted: Jun Mon 15, 2009 2:25 am 
Member

Joined: Oct Sat 20, 2007 3:36 am
Posts: 14393
Location: Southern NH, 03076
JK and Curt nailed it right on.

Most of the audiophool crowd have a monkey see monkey do mentality. Some dimbulb starts a thread on Audiokarma or elsewhere and pretty soon the myth becomes gospel.

Then its no wonder that those who know better sell off old garbage for big bucks. And laugh their heads off.

As P.T. Barnum said "A sucker is born every minute" or words to that effect. Sorry to hear that you got burnt but at least no damage was done to the equipment.

Carl


Top
 Profile  
 
 Post subject:
PostPosted: Jun Mon 15, 2009 4:12 am 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 129
Location: Roslyn Heights
Thanks guys I have seen this so many times on E bay and other sites.
that's it no more NOS capacitors.
Has any one out there bought these capacitors.???
I saw on E bay box of 100 brown enamel same brand type .05 @600 volts sold for over $300.00 that is nuts..
Jim
thanks for the time guys


Top
 Profile  
 
 Post subject:
PostPosted: Jun Mon 15, 2009 5:12 am 
Member
User avatar

Joined: Jan Thu 01, 1970 1:00 am
Posts: 13246
Location: Tennessee,USA
Hi Jim,
A agree with the others.

You said you went for some? If I were you, I'd put them back on Ebay and get at least some of your money back. As stated, the audio guys will often pay huge amounts of money looking for the "perfect" sound. They will never get it, especially with the hyped NOS parts.

If some were within 20% of marked value, you might use them in a non critical circuit like tone. If they are way off, I'd not bother with them. Maybe make something artistic with them :)

If you are going to restore old radios, I don't think there is a need to pay top dollar for some so called 'best caps' out there. With an old set, any real or preceived diference will not be heard.

I looked on Epay right now adnd there were some ELMENCO caps, brown dipped type. They may be ok, but 2 for $3.99 and $3.50 shipping, no way.


Top
 Profile  
 
 Post subject:
PostPosted: Jun Mon 15, 2009 6:04 am 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 2715
Location: Monterey California USA
The other problem with electrical leakage in these caps is that it is just going to get worse, and eventually they short, depending upon how much voltage they are subjected to. When that happens, they take other parts with them and things go up in smoke. I never liked the tonal quality of a power transformer burning up or the sound of resistors incinerating themselves...

_________________
WB6NVH


Top
 Profile  
 
 Post subject:
PostPosted: Jun Mon 15, 2009 8:06 am 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 129
Location: Roslyn Heights
"I looked on Epay right now adnd there were some ELMENCO caps, brown dipped type. They may be ok, but 2 for $3.99 and $3.50 shipping, no way."
Hey I hear you if you want go to completed sales on E bay of the same capacitors
I couldn't believe what they went for.
I the biggest problem I have with these is that they are leaky some only .5 volts and some as high as 3 or 5 volts.
That to me is just asking for danger in a high voltage path.
I will post them on E bay this week.
any other comments on this as to the mojo.
I do hear a difference in guitar amps when using different types of capacitors for what it's worth.
Thanks again
Jim


Top
 Profile  
 
 Post subject:
PostPosted: Jun Mon 15, 2009 2:33 pm 
Member

Joined: Nov Wed 07, 2007 12:44 am
Posts: 1664
Location: Hawthorne, Ca
There might be a difference in sound quality between a film and foil cap like an orange drop and caps that are metal film like the little yellow ones that we use for radio restoration. I like the orange drop 715 or 716p polypropolene and foil caps for audio work as they are constructed like the original paper and foil caps and the price for them isn't insane. I wouldn't even think of using NOS caps as I don't want to risk an expensive tube or transformer because an audiofool says that a certain nos cap brings you to closer to audio nervana. Remember what Hitler said, if you tell a lie often enough, people will believe it. Harry


Top
 Profile  
 
 Post subject:
PostPosted: Jun Mon 15, 2009 11:28 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 843
Location: Rockford IL USA
If I remember my high school Spanish, El Menco is Spanish for "The Leaker."


Top
 Profile  
 
 Post subject:
PostPosted: Jun Tue 16, 2009 2:51 pm 
Member
User avatar

Joined: Jan Thu 01, 1970 1:00 am
Posts: 6446
Location: Beaver Falls, PA. USA
Any capacitor made before the mid-1960s is suspect, regardless of the manufacturer. The molded and sealed types were thought to be the best in their day, but they are still paper inside.

_________________
Tim KA3JRT


Top
 Profile  
 
 Post subject:
PostPosted: Jun Tue 16, 2009 3:20 pm 
Silent Key

Joined: Jan Thu 01, 1970 1:00 am
Posts: 34328
Location: Sandpoint, IDAHO 83864
I think one of the major root causes of failures in these molded and sealed capacitors is due to compromising the seal when the leads are bent at sharp angles next to the body of the capacitor when installing them. This can crack the seal and allow moisture to enter over time.

In the Navy, we were taught to always use a pair of needle nose pliers to hold the leads next to the body so they came straight out for about 1/8" and then make the bend needed.

The same applies to those postage stamp micas and paper capacitors. They always seem to be installed upside down in a chassis and you have to twist their body to read the color coding of the dots, and this breaks the old dried and fragile seal where the wires enter the body of the capacitor, so if it is not bad now, it will be in a short matter of time, depending on the ambient humidity.
Curt

_________________
Curt, N7AH
(Connoisseur of the cold 807) CW forever!


Top
 Profile  
 
 Post subject:
PostPosted: Jun Tue 16, 2009 3:24 pm 
Member

Joined: Jul Mon 21, 2008 5:17 pm
Posts: 1023
Location: SW Ohio
I recently replaced a hand full of bumble caps in a Zenith Transoceanic H500. They included several of those highly sought after "Les Paul .022mf" caps (whatever that means??). Sold the handful on ebay for what I paid for the whole radio...$40 I think. Go figure??

Darn. I couple of them I couldn't sell because they were literally split into two pieces! But, I'm not going to throw them away... you never know when they'll become valuable too! :lol:

_________________
Joe
WW8X


Last edited by canerods on Jun Tue 16, 2009 4:37 pm, edited 1 time in total.

Top
 Profile  
 
 Post subject:
PostPosted: Jun Tue 16, 2009 3:40 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 2307
Location: S/E Michigan
Burnt Fingers wrote:

Then its no wonder that those who know better sell off old garbage for big bucks. And laugh their heads off.

Carl


Agreed! :wink:

News flash (not to Carl). Most are well aware of the danger, having heard it dozens of times, in the buyers own words. I've sold dozens & dozens to Audiophiles. While they have a different opinion on the caps value (one mans garbage, another mans gold), many are actually quite experienced in electronics and well aware of the danger depending on their use.

_________________
-Brian


Top
 Profile  
 
 Post subject:
PostPosted: Jun Tue 23, 2009 7:55 pm 
Member

Joined: Apr Wed 08, 2009 6:28 pm
Posts: 239
Location: Spartanburg, SC
I use the 716 Orange drops or the Mallory 150s. I personally like the 150s as they are axial lead and easier to install on a Fender type eyelet board.

I have never heard any difference in the sound of a capacitor in a guitar amp.


Top
 Profile  
 
Post New Topic Post Reply  [ 17 posts ]  Moderators: Marcc, Norm Leal

All times are UTC [ DST ]


Who is online

Users browsing this forum: No registered users and 8 guests



Search for:
Jump to:  



















Privacy Policy :: Powered by phpBB