1/4 A slow blow for HT fuse?
Moderators: pompeiisneaks, Colossal
1/4 A slow blow for HT fuse?
I am building a Fender AB763 type of circuit (two 6L6, 4 triodes).
I want to ad an HT fuse to protect the output tranny. Is 1/4A sufficient (slow blow), or do I need 1/2A (slow blow)?
I want to ad an HT fuse to protect the output tranny. Is 1/4A sufficient (slow blow), or do I need 1/2A (slow blow)?
Re: 1/4 A slow blow for HT fuse?
I'd use a 500mA T fuse for 2 x 6L6s
Re: 1/4 A slow blow for HT fuse?
o.k...here I go exposing my ignorance.
What is a "T" fuse. Is that fast or slow,or something else.
What is a "T" fuse. Is that fast or slow,or something else.
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Re: 1/4 A slow blow for HT fuse?
Slow blow I think. I know that fast blow fuses last all of 2 seconds in the HT position. 500mA SB is the guy for most push pull pairs.
Cliff Schecht - Circuit P.I.
Re: 1/4 A slow blow for HT fuse?
Sorry "T" in this instance is an abbreviation for 'time fuse' - i.e.: a slo-blo fuse (even tho' 'time' can be fast or slow depending on how fast you are going)
Re: 1/4 A slow blow for HT fuse?
From my reading around the web, I gathered that an SB on the B+ will be too slow to do any good - ie save the output section. I use FB and with the tube rec amps they hold up well. Occasionally one will will pop using the stanby but it's been rare. FB with SS rec doesn't stand a chance. Please correct if I'm wrong.
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Re: 1/4 A slow blow for HT fuse?
IIRC the standard for 50W Marshalls has always been 500mA fast blow. Personally I would be loath to use a slow blow fuse on the HT, with or without SS rectifier, in any design.
Lately I have only used a fuse in the power section on the CT of an old vintage OT I do not want to lose. 200mA fast blow. This in a 50W amp. I also used a 500mA slow blow on the CT of the PT too, as it was also vintage iron. These are inline fuses inside the chassis, I also use a 2.5A slow blow on the PT primary.
Lately I have only used a fuse in the power section on the CT of an old vintage OT I do not want to lose. 200mA fast blow. This in a 50W amp. I also used a 500mA slow blow on the CT of the PT too, as it was also vintage iron. These are inline fuses inside the chassis, I also use a 2.5A slow blow on the PT primary.
Re: 1/4 A slow blow for HT fuse?
I've used 200mA SB in the secondary CT-to-ground of my 18W design. I'm pretty sure this is not the right way to do it, but definitely took it off a schematic as i knew very little about building amps back then.
i'm omitting the fuse on the secondary entirely in my soldano atomic 16 build though.
i'm omitting the fuse on the secondary entirely in my soldano atomic 16 build though.
In the interest of full disclosure, I am Animal Factory Amplification.
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Re: 1/4 A slow blow for HT fuse?
I have been taught by my amp mentor that T stands for Time Delay.
I have been using T for MAINS fuse and fast for HT fuse.
-T
I have been using T for MAINS fuse and fast for HT fuse.
-T
Re: 1/4 A slow blow for HT fuse?
Yeah same diffDingleberry wrote:I have been taught by my amp mentor that T stands for Time Delay.
I have been using T for MAINS fuse and fast for HT fuse.
-T