Why an audiophile mains fuse?

As all the electricity feeding your system has to pass through it, the fuse in a mains plug will inevitably affect performance, so it makes sense to ensure that this fuse creates as little impedance to the flow of power as possible.

In the past, some audiophiles tried to address this problem by bypassing the fuse in various ways, but that is something we definitely do not recommend, as the fuse is there for safety reasons (* see below).

Developing a better-performing fuse, which has a less degrading impact, is therefore the obvious solution.

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.


It’s not the fuse itself that makes our fuses different; it’s what we do to them.

We started by testing a number of high-quality standard fuses to find the one that sounded the best - w
e spent an extensive period of time listening to a wide variety of commercially available fuses in order to whittle it down to the best sounding in its 'native' state. The model we chose – made by Bussman – features nickel-plated end caps and a silver-plated fuse wire… but it’s the application of our unique Process Q that takes it to another level.

Process Q is the result of years of extensive research and a long-term, ongoing, development project costing well over £250,000 (the name of the original process was Super Burn-in, although this was a little confusing because Super Burn-in altered the cable in a way that cannot be achieved by the natural 'burn-in' process ). 

The project has led to the latest iteration of the processing apparatus, which is able to enhance the original Super Burn-in even further via Process Q, used on our top-level UltraFuses. This Process Q™ machine is now also used to apply the legacy Super Burn-in to our SuperFuses.

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.

A Process Q recipe for fuses

Process Q
(and Super Burn-in before it), was originally developed to be applied to our mains, interconnect and speaker cables, all of which were of a far heavier gauge than a fuse wire, so the system had to be adapted. This took many months of research and testing but eventually we developed a special ‘recipe’ specifically for the fuses, utilising a custom jig in order to process a number of fuses at the same time (necessarily for the process to be applied in these instances).

Because of the level of investment we have made, we are understandably reluctant to reveal specific details of what the process entails. Suffice to say that the results speak for themselves – pound for pound, our fuses probably offer one of the most surprising levels of performance of all our products; just check out the customer reviews!

Don’t forget – SuperFuses
and UltraFuses are a simple replacement for your existing mains plug fuse, so you can easily test them for yourself in your own system, taking advantage of our 60-Day Money-Back Guarantee.

Buy SuperFuse™ here and UltraFuse™ here.


There's a good reason we don’t manufacture the fuses ourselves

Being blunt, it is simply not commercially viable for a smaller company like us to manufacture their own fuses. Fuses are only inexpensive because of the huge scale of production. They may look simple but are actually a quite technical device; they must be structurally safe, robust, be utterly reliable in use for decades, and they must have a predictable temperature coefficient, so they will blow consistently at the rated current and also withstand occasional transient overload without 'false fault' failures.

We need the resources of a large-scale manufacturer behind us to keep our fuses safe for you to use whilst also keeping the costs affordable. Good manufacturers make good fuses for general use, but we can make them perform much better for our Hi-Fi needs, and that’s where Super Burn-in
and Process Q come in.

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 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 & UltraFuses are available in 13A, 10A and 5A versions. The 13A SuperFuse or UltraFuse is the correct value to fit into one of our Russ Andrews power cables, as these are all rated at 13A, regardless of what they are being plugged into (*see 'What are mains fuses for' below).
Russ Andrews 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.

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?

* What are mains fuses for?

Where they are used – and it’s only a minority of countries that do – mains plug fuses are a necessary evil, there to protect the cable from over-heating and potentially causing fire. It’s a common misconception that this fuse is there to protect the equipment it is plugged into, but this is not the case; components have their own internal protection fuses.

UK Fuses relate to the cable not the product the cable is fitted to

The fuse in a mains plug is related purely to the cable it’s attached to and bears no relation to the piece of equipment the cable is supplying.

So, if a cable has a 5A fuse, that’s because the cable is rated at 5A. If there was a fault with the mains cable causing more than 5a to flow, the 5a fuse would blow first to prevent an unsafe current being conducted by the mains lead. All our cables are rated at well over 13A, so use the maximum standard-rated value 13A fuse. This means that if you replace the 5A-rated cable with one of ours, you would now use a 13A fuse (you’ll notice that the 5A cable is a lot thinner).

Buy SuperFuse™ here and UltraFuse™ here.