Death cap

[cowboy]

Hi, as some of you know, I've bought a Silvertone 1484, and I've intended to remove the death cap on that sucker. Now, since I'm new to electronics, and haven't got an education, can someone please give me some info on where it is and how to remove it?

Schematic of the amp:

http://www.miduho.com/jp/st/amp-kair...itar%20amp.gif

Thanks! J.T

[tedmich]

its c31 (0.05uf) going from power lines/switch to ground.

You should install a safe 3 prong grounded power cord too, see:
Install - 3 Prong Power Cord on a Vintage Fender Amp | Guitar Files(TM)

you can also avoid some noise by adding so called X and Y caps, see here:
ABC's of Safety (Interference Suppression) Capacitors for Tube Radios


Or by installing a IEC type cord inlet filter which includes X/Y caps, and maybe a fuse:
6A/250V POWER INLET & RFI MODULE-MPJA, Inc.

[txstrat]

Remember, the green wire to ground would be the green-yellow in Europe.

[Bruce / Mission Amps]

DEATH CAP....

Does anyone actually know anyone that has been killed, seriously or mildly injured by this much maligned capacitor?

Seriously... in my opinion, this death cap term is, wanna be amp guru, NET driven hysteria with virtually very little real world data to back it up.
Most of these caps across a 120v-240v line are rated at 400v to +600v, plastic film, poly something or another caps and not cheap junk.

To be honest, I think I have only seen one or two of these caps gone bad since I built my first vacuum tube radio in 1963-1964.
By comparison, I've seen a hundred or more frayed power cords dangling from a sharp hole in a chassis where I was afraid to touch it and the goof ass is still using the damn thing!

I do agree, replacing any two wire power cord with a three wire cord, (one that has a separate chassis ground wire), is a real important improvement and I recommend it be done to all your two wire power corded vintage equipment... but that has nothing to do with this so called Death Cap.

There are so many other real dangerous things with 120vac-240vac power line devices that I really have to laugh at the notion of this cap being the almighty,
Death Cap.

[tedmich]

IME the propensity to overemphasize the danger inherent in many pastimes is highly linked to the Y chromosome

[Enzo]

I never interpreted the term as being historical. Just a dangerous holdover from a bygone era. When I was on the road in the 1960s, first thing we did after basic setup was go through the gear setting the ground switches for least shock. Even when the cap is perfectly 100% as a cap, it still can leave a nasty charge on the chassis with respect to some other piece of gear.

I have one fond memory of the evening our guitarist raised the neck of his guitar up and his strings brushed the microphone - and he burnt his E-string in half. BZZZT.

Even if the cap doesn't make the amp deadly, it can still cause injury and discomfort.

I work in video monitor land from time to time. Color monitors have 30,000v on the CRT. I avoid coming in contact with it. I am not concerned I will be electrocuted, I am more afraid I will break my arm reacting to it. Ever touch something live and find you just threw whatever was in your hand across the room?

[Gtr_tech]

I work in video monitor land from time to time. Color monitors have 30,000v on the CRT. I avoid coming in contact with it. I am not concerned I will be electrocuted, I am more afraid I will break my arm reacting to it. Ever touch something live and find you just threw whatever was in your hand across the room?

I was always *very* careful around second anode connections. Discharged them with a HV probe, left it connected while removing the snap connector, discharged it again before reconnecting. Since the tube acts as a capacitor, it can "remember" a bit of its charge.

I miss working on the game stuff, but I have bad memories as well. While working on a pinball in a row of about 15 of them I found one that had the gnd pin broken/cut off the line cord. Brushed against the class lock bar while touching a grounded machine. Got woke up *real* quick and changed the line cord end. Then....I think it was the same day, I had one unplugged. Crawled under the row to plug it back in and.....*POOF*.....big blue flash and my hand/forearm was black. Threw a fit at the owner and told him to have the wiring fixed. He's prolly still laughing about it since he was a "class ass".

[Prairie Dawg]

Does anyone actually know anyone that has been killed, seriously or mildly injured by this much maligned capacitor?

Seriously... in my opinion, this death cap term is, wanna be amp guru, NET driven hysteria with virtually very little real world data to back it up.
Most of these caps across a 120v-240v line are rated at 400v to +600v, plastic film, poly something or another caps and not cheap junk.

To be honest, I think I have only seen one or two of these caps gone bad since I built my first vacuum tube radio in 1963-1964.
By comparison, I've seen a hundred or more frayed power cords dangling from a sharp hole in a chassis where I was afraid to touch it and the goof ass is still using the damn thing!

I do agree, replacing any two wire power cord with a three wire cord, (one that has a separate chassis ground wire), is a real important improvement and I recommend it be done to all your two wire power corded vintage equipment... but that has nothing to do with this so called Death Cap.

There are so many other real dangerous things with 120vac-240vac power line devices that I really have to laugh at the notion of this cap being the almighty,
Death Cap.

+1 on the terminology. It's kinda silly.

Especially in this day and age there are better solutions. If you've been around radio you're probably familiar with metal case Arvins Bruce. These were three and four tube metal case radios made by the folks at Arvin (who are still around by the way). Their expertise is in metal stamping.

Even though the paint served as a pretty fair insulator you can still feel the juice flowing through them with your bare hands, especially if the two wire plug is reversed.

Where this gets funny is when I go to a radio show or see one for sale on fleabay that's been chromed. That's positively dangerous.

if you've got one, it's strictly for "on the shelf", hands off listening.

[Euthymia]

There is one time when that terminology comes in handy, and that's when I need to persuade someone who wants his amp to remain ABSOLUTELY 100% STOCK that it's still a good idea to clip that stupid thing out of there.

I call it the "zap cap." And while I have seen few that were actually hard shorted, they trip the GFCI on my bench about once a month.

[Alex R]

As I understand it these caps are there to produce a 'neutral', or zero-volt, or ground-related terminal, so one side of the AC stays at zero whilst the other fluctuates around it. If you have a mains supply that does that anyway, like most folks do these days, there is no point in the cap. Am I right?

[Rick Erickson]

SVT Death Cap... any questions?

[uvacom]

I just think it should have an even more damning name. I propose "Satan's Juicebottle".

[Brazen]

its c31 (0.05uf) going from power lines/switch to ground.

You should install a safe 3 prong grounded power cord too, see:
Install - 3 Prong Power Cord on a Vintage Fender Amp | Guitar Files(TM)

you can also avoid some noise by adding so called X and Y caps, see here:
ABC's of Safety (Interference Suppression) Capacitors for Tube Radios

Or by installing a IEC type cord inlet filter which includes X/Y caps, and maybe a fuse:
6A/250V POWER INLET & RFI MODULE-MPJA, Inc.

I realize this post is old, but I wanted to ask..... I assume this part will suffice and even surpass your original recommendation above?

RFI Line Filter 10A, 250VAC Module, Delta

DELTA 10ME3, PC board/Panel mount, power inlet/RFI Filter. Rated: 10A @ 115/250VAC. Standard male 3 blade IEC cord connector. Right angle solder output terminals, UL/CSA /VDElisted.
W: 2" H: 1-1/32" Body D: 1-5/8" WT: .1

RFI Line Filter 10A, 250VAC Module, Delta | MPJA.COM

Thanx in advance!
Jimmy