BOSE SK3 SK-3 Tweeter Bulb Fuse [UPGRADE RED TO BLUE DOT] more protection READ

ONE BLUE DOT FUSE / BULB.

[UPGRADE RED TO BLUE DOT] more protection READ

Speaker Crossover Fuse SK3 Osram Sylvania 569 12V 1A  for Tannoy, JBL, Bose, EV, Convair, Electro Voice Peavey, WHARFEDALE, Pro-Audio.

HF / Tweeter Bulb Fuse.  [UPGRADE MORE PROTECTION].  This is a UPGRADE, MORE PROTECTION.  Please read.

HF / tweeters bulb / fuse upgrade protection.  Upgrade from RED DOT >>> BLUE DOT.  One [UPGRADE] Fuse / Lamp for speaker Crossovers, as fitted many speakers crossovers.

Simply, this offers more protection, especially for PA speakers and bands & people who play their speakers loud.  So many speakers / amplifiers etc, that have a fuse fitted, and looks like this, is a SK3 type (its has many names).  Also identified as a RED dot.  There is a lesser known similar looking fuse, but has a BLUE dot.

So simply … Most products use RED dot.  A few use BLUE dot.  Upgrade from RED to BLUE gives more protection.

RED DOT.

Approx. 12V @ 2A rating.  So 24 watt as a bulb. BUT as a fuse / protection device, in Negative Temp Coefficient form, That means as the current increases, the ohms increase = greater protection.  COLD TEMP (10 to 30 Degs C) = 0.5 ohms.  That means you have a 0.5 ohm resistor in series.  Under HOT temp conditions, its 6 ohms.  Given the HF / tweeters is 5 to 8 ohms typically, it adds a lot of safety resistance, as the power goes up.

BLUE DOT.

Approx. 12V @ 1A rating.  So 12 watt as a bulb.  BUT as a fuse / protection device, in Negative Temp Coefficient form.  That means as the current increases, the ohms increase = greater protection.  COLD TEMP (10 to 30 Degs C) = 1 ohms (twice the RED dot).  That means you have a 1 ohm resistor in series.  Under HOT temp conditions, its 12 ohms (twice the RED dot).

Given the HF / tweeters is 5 to 8 ohms typically, it adds a lot of safety resistance, as the power goes up.

To summarize …

RED DOT = 0.5 ohms cold = amp at low power.

RED DOT = 6 ohms hot = amp at high power. 

BLUE DOT = 1 ohms cold = amp at low power.

BLUE DOT = 12 ohms hot = amp at high power.

SEE PICS ... BOX FROM FACTORY SHOWS WE SUPPLY GENUINE AND REAL OSRAM SYLVANIA.

We sell the genuine & correct Tannoy, JBL, EV, Electro Voice,  Convair, Bose, Peavey etc & many others lamp fuses.

These are built in the USA, by Osram Sylvania to the correct specification, who also make lamps bulbs for the US Military, these are not cheap China copies.

DO NOT FIT NON GENUINE FUSE / LAMPS. NOT EVER EVER EVER.