Failsafe

83.84.192.219

Posted on March 5, 2012 at 09:33:00

Hi guys,

I am new and will soon start to read the entire forum about OTL!
In the meantime who can help me out...who knows everything about OTL

Here goes I have AITOS OTL pretty much a clone to the great Futterman layout.
Now I notices that the tube sockets of the PL-519 have a very thin wire made out of fuse wire....

What is its function surely not to fuse as my Aitos bears 3 fuses which will blow a lot sooner I am quite curious......

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09:48:50 03/05/12

10:01:26 03/05/12

rhinohifi714

11:12:37 03/05/12

3

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09:48:50 03/05/12

10:01:26 03/05/12

rhinohifi714

11:12:37 03/05/12

3

Really?

Lew

13:26:52 03/05/12

RE: Really?

14:29:42 03/05/12

RE: Really?

Ralph

11:24:44 03/06/12

RE: Failsafe, posted on March 5, 2012 at 09:48:50
714rhino	that wire is a fuse, its there to protect the tube when too much current is being drawn.

RE: Failsafe, posted on March 5, 2012 at 10:01:26
Erik van Voorst	Thanks 714rhino That is what I thought but surely the other fuses (0.8A 63mA 1.4A 0.1A) will go first. Can you tell me if you have an idea what the approx value of that wire can be. Your help is appreciated.

RE: Failsafe, posted on March 5, 2012 at 11:12:37
rhinohifi714 Audiophile Posts: 84 Location: oklahoma Joined: June 13, 2009	in the futterman's it is a 2amp fast blow, I would try a 1.6a or 1.8a to start with before I went with a 2a.

Really?, posted on March 5, 2012 at 13:26:52
Lew Audiophile Posts: 5289 Location: Bethesda, Maryland Joined: December 11, 2000	Are we talking about the fine wire fuse at each output tube? Wouldn't those be lower current types? I doubt that an EL519 can take anywhere near 2A, but this is pure speculation on my part.

RE: Really?, posted on March 5, 2012 at 14:29:42
Erik van Voorst	Yepp according to Futterman 0.05 mm equal to 0.5A but why change it over the uears to 2A fast blow....who is technical enough to explain first of all its use....and second the change to a much higher value......as told I have also the 3 other fuses... Thanks for thinking along with me

RE: Really?, posted on March 6, 2012 at 11:24:44

Ralph
Manufacturer

Posts: 2180
Location: Minnesota
Joined: April 24, 2002

500mA sounds like that would be OK for one power tube like a 6LF6, PL509 or the like. 2 amps OTOH is simply asking for trouble, but I imagine the higher rating might sound a little better as fuses can vary their resistance a little depending on the current flowing through them, and a 2A would be less responsive.

But you really don't want to find out what happens if you need that 500mA fuse! Just make sure its properly installed and no-one gets hurt :)

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Failsafe

83.84.192.219