What are SuperFuses and UltraFuses?

Russ Andrews SuperFuses and UltraFuses are high performance mains plug fuses that are designed to replace the standard fuse fitted to UK-style 13A mains plugs. All Russ Andrews power cables are supplied with good quality, standard fuses - which we have Deep Cryogenically Treated (DCT) - but we recommend fitting our SuperFuses or UltraFuses for best performance. 

If you request them when ordering a new cable we will automatically fit them for you, or you can buy them separately and retro-fit them to existing Russ Andrews cables, or to any other manufacturers' power cables.
SuperFuses and UltraFusesIn addition to mains plug fuses, SuperFuses are also available as the smaller 20mm internal fuses commonly fitted to components such as CD players or amplifiers. 

Superfuses receive our legacy Super Burn-In
treatment and UltraFuses undergo the unique Process-Q - both are then hand-treated with DeoxIT® contact enhancer. They are suitable for fitting to all Hi-Fi equipment power cables and equipment; the mains plug fuses are manufactured to BS1362.

Why did we develop them?

No matter how good a mains cable you use, electricity still has to pass through that small piece of fuse wire in the mains plug. It therefore makes sense to ensure that this fuse creates as little impedance to the flow of power as possible. We had already achieved good performance from standard DCT 13A mains plug fuses, then back in 2014 Russ applied a specially developed version of our Super Burn-in process to our fuses. We built a jig and spent some time perfecting the Super Burn-in recipe, so it was suitable for applying to both mains plug fuses and internal 20mm equipment fuses. When we tested them, we were delighted with the results.

Now that Super Burn-in has been replaced by Process-Q, we use the new machine to treat SuperFuses with the legacy 'Super Burn-in recipe' to deliver even better results.

The new Process Q apparatus has also enabled us to develop more sophisticated and complex processes that far exceed the performance of the original SuperFuse recipe. The result is UltraFuse – our best mains plug fuse yet.


What's included?

When you buy our SuperFuses and UltraFuses separately, we include a DeoxIT Gold wipe in addition to the fuse itself. This allows you to treat the fuse and the plug’s fuse holder with the contact enhancer just before you fit it. 

SuperFuse contents

We also include a 'Fitted with Russ Andrews SuperFuse/UltraFuse‘ label to attach to your mains plug or equipment casework so you can keep track of where you have fitted your upgraded fuses. This also replaces the "Warranty Void if Removed" sticker which comes as standard on our mains cable plugs; don't worry, that is just there to discourage anyone from interfering with the termination and the remainder of your 25 year cable warranty will still be valid once you've replaced the fuse. 

Full fitting instructions are included and the fuse is supplied in a protective pouch (SuperFuse) or case (UltraFuse). Packs of 5 SuperFuses fuses include five individual fuses of the same value, five labels, one DeoxIT Gold wipe and one set of instructions.

SuperFuse and UltraFuse values

Mains plug SuperFuses are available in 13A, 10A and 5A versions and the UltraFuse in a 13A version only. The 13A SuperFuse or UltraFuse is the correct value to fit into one our Russ Andrews power cables, as they are all rated at 13A.
Russ Andrews SuperFuses
SuperFuses and UltraFuses can also be fitted to other manufacturers' power cables, and as a rule-of-thumb you should replace an existing fuse with the same value of SuperFuse or UltraFuse. To find out more about choosing the correct value of mains plug fuse for your power cable, read our Buying Guide: Choosing The Correct Value Of Fuse.

Internal SuperFuses are available in slow blow (
timed) or fast blow versions. We have a range of values available in both types from 100mA to 6.3A and internal fuses must be replaced with a SuperFuse of the same value and type. The value of the fuse should be stamped on the end cap of the fuse, though you may need a magnifier to see it: Slow blow fuses will be prefixed with a 'T' before the value - e.g. T 3.15A.

UltraFuses are currently only available as a 13A version to replace the fuse of a 13A rated cable.

Fitting SuperFuses and UltraFuses

SuperFuse StickerSuperFuses and UltraFuses are a straight swap for existing fuses. To replace the fuse in a mains cable, open the plug and replace the fuse with a SuperFuse or UltraFuse of the same value. Once fitted, screw the plug back together and stick on one of the included 'Fitted with a Russ Andrews SuperFuse/UltraFuse' labels (see above & right). 

To replace internal fuses with our SuperFuses, you may need to consult your equipment manual to find out how to replace them. If you are lucky, you will find the internal fuse is built into the IEC socket on the back of your amplifier, or on the back panel, and it's easy to swap it without opening your equipment's casework - see below.

Fitting an Internal SuperFuse

In other cases, it may be that the fuse is fitted internally and you need to remove the casework lid to get access to it. Remember, it's important to replace your fuses with a SuperFuse of the same value and type.

100% satisfaction or your money back


Remember that fuses are designed to fail in the event of a fault occuring in the cable they are fitted to, or to the equipment they are fitted in. This is for safety and may indicate a fault with the component. SuperFuses and UltraFuses are, therefore, excluded from our Lifetime Warranty. Unfortunately, our Cable Upgrade Scheme does not apply to fuses and you cannot upgrade existing SuperFuses to UltraFuses.

However, we're so confident that you'll be happy with the performance of your new SuperFuse or UltraFuse that they are covered by our 60 Day Money Back Guarantee, which means you can audition them in your own system for up to two months - and if you’re not 100% satisfied with the improvements, you can send them back for a full refund. You can’t say fairer than that, can you?

Russ Andrews 13A SuperFuse fitted to PowerKord