QED Performance Audio 40i Digital Audio Cable - Custom Length

Item code: Audio 40i Digital Custom

4.8 17 reviews ✓ Verified
Building on the success of the award-winning Performance 40, QED's Performance 40i contains two 99.999% OFC conductors of different diameters to accommodate high-frequency audio components and a foamed polyethylene dielectric. The result is remarkabl…
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SPEAKER CABLES:

A quantity of 2 means you will receive a pair of speaker cables e.g. for your front left and front right speakers. By entering a quantity of 1, you will get a cable for a single speaker e.g. centre speaker and this option also enables you to vary the length (and termination) of your cable for each speaker.

OTHER CABLES:

A quantity of 1 means you will receive a single cable in the case of aerial, satellite, subwoofer, digital coaxial & optical cables and a pair of cables in the case of 2 rca to 2 rca analogue audio cables.

NON-CABLE PRODUCTS:

A quantity of 1 means you will receive 1 of the specified products.

£18.75 ex. VAT
Available — built to order, dispatches in 24 hours
Delivery: Royal Mail Tracked 24  ·  DPD Next Day from £8.95  ·  DPD Saturday from £12.95
Order before 4pm (Mon–Fri) for same-day dispatch
Our promise: 60-day returns · Free burn-in · Built in our UK workshop · Lifetime warranty · Expert support on every order

QED Performance Audio 40i Digital Audio Cable - Custom Length

 

Building on the success of the award-winning Performance 40, QED's Performance 40i contains two 99.999% OFC conductors of different diameters to accommodate high-frequency audio components and a foamed polyethylene dielectric. The result is remarkably well-defined sound at a very competitive price.

 

What QED say

Performance Audio 40i builds on the strengths of the original Performance Audio 40, and delivers an even more enjoyable and convincing sound - without affecting its prodigious value for money. Using the principles laid down in its industry-defining Genesis Report, as well as some startlingly original technology (including the ground-breaking Solid Complementary Conductors and Anamate plugs), QED has created an interconnect that puts as much distance between itself and its nominal competition as the original Performance Audio 40 did over six years ago.

 

Floating Internal Ferrite Jacket

A special floating Zn/Mn Ferrite jacket is used within the Audio 40 cordage to absorb very high-frequency noise components outside of the audible band that have an adverse effect on the micro-timing of the audio signal. With cables, our goal is to replicate as closely as possible the input signal at the cable output. Timing errors mean frequencies have been disrupted and the signal sent by your source equipment has not been accurately replicated. When measured at very high frequencies, Audio 40 cables do exhibit cleaner signal transmission than ordinary audio interconnects.

The ferrite insulation delivers measurable improvements to both the amount of high-frequency signal noise rejected by the cable and the amount of relevant signal information lost. The improved accuracy of high-frequency impulse transmission impacts positively on timing, and on dynamics both broad and low-level.

 

ANAMATE™ RCA Plugs

The ‘Anamate’ arrangement of the plugs, in which the high purity copper conductors are gold-plated, gives Performance Audio 40i both the low-contact resistance needed to produce thrilling sonic results and also far greater longevity than unplated copper alone. By using high purity copper conductors for the pin section and small contact areas for the return ring, the resistance in the signal path is lowered. It also prevents eddy currents forming in the plug body, which in turn improves signal transmission.

 

Complementary Conductor Technology

Beneath the PVC jacket, braided foil shield, ferrite jacket and foamed polyethylene dielectric are two solid, electrically isolated and oxygen-free copper conductors of different diameters. Using two wholly separate conductors (one copper, one silver-plated) to carry the audio signal provides the most complete, least compromised route for audio information to travel. The resulting sound enjoys greater scale and three-dimensionality than has been previously achievable from an interconnect of this price, and helps QED maintain both its reputation as an innovator and a class-leader.

Improves timing and detail, retaining the rhythm of the original piece. Unlike conventional analogue interconnects, Performance Audio 40 utilises two 99.999% Oxygen Free Copper conductors of different diameters to carry the same audio signal. This has the effect of providing an alternative path for high frequency audio components which might otherwise become time smeared in a single audio pathway.

 

Just Listen

Performance 40i has numerous technological highlights, and we’re convinced it represents amazing value for money. The easiest way for you to understand what we mean is to hear it in action for yourself - we’re confident you’ll prefer it to any alternative cable at anything like the price.

 

Specification :

  • Conductor type: Solid Complementary
  • Metallurgy: 99.999% OFC & SPOFC
  • Conductor size: 1 x 0.643 mm & 1 x 0.404 mm
  • Combined conductor cross-section: 0.45 mm²
  • Dielectric: Foamed Polyethylene
  • Capacitance: 57 pF/m
  • Self-inductance: 0.45 μH/m
  • Loop resistance: 0.050 Ω/m
  • Dissipation factor @ 10kHz: 0.00250
  • Outer jacket: Black Pearl PVC
  • Nominal outside diameter: 8.0 mm
  • QED Lifetime Guarantee

 

About QED Cables Made in United Kingdom

QED is an award winning British company with over 40 years of experience in the audio-visual connectivity industry.

In 1973 Bob Abraham and Ian Vine founded QED Audio Products and changed the way people think about hi-fi cables. By the time QED 79 strand speaker cable was launched in 1978, it wasn’t looked upon as ‘just another speaker cable’ but was instead regarded as a serious hi-fi component, making a fundamental change in the way people thought about cables.

QED's reputation for innovation and technical excellence is known throughout the world. The latest computer-aided design techniques allow their research and development team to keep pace with technological advances and deliver products that achieve the highest levels of performance and reliability. This is why QED products are recommended by so many of the world’s leading hi-fi and home theatre equipment manufacturers.

QED offer a range of connectivity products spanning from both consumer and installation cables, wireless products and switching devices to satisfy every audio visual need.

QED is Europe's number one award winning connectivity brand and has won more prestigious cable awards from ‘What Hi-Fi? Sound & Vision’ magazine than any other brand (Awards 1981–2013).

About QED Cables

British cable maker covering speaker, analogue, HDMI and digital cables, plus speaker and network cable for installers.

QED is a British company that makes connection products for audio and video systems. The catalogue covers speaker, analogue, XLR, phono, subwoofer, USB, optical, coaxial, Ethernet and HDMI cables, and mains cables. For installers it offers the QX16 series speaker cable and a CAT network cable.

Read more about QED Show less

Installer products for longer runs

QED's main installer products are the QX16 series speaker cable and its CAT network cable. Both suit cable that has to be run through a house or a room rather than a short link between two components, which is the job the rest of the range covers.

A full set of digital and video connections

For digital and video connections, QED makes HDMI cables, USB cables in A-B and A-Micro B formats, and optical, coaxial and Ethernet cables. That covers most of the digital connections in a modern system, from a streamer to a TV.

Analogue connections from one maker

For the analogue side of a system, QED makes speaker cables, analogue interconnects, XLR and phono cables, subwoofer cables and mains cables. That gives you the connections between your source, amplifier and speakers, and the power feeding them, from a single British maker.

Why we stock QED

QED was one of the first brands we ever ordered, back in 2005 when we started. We have sold them every year since. Twenty-one years with one brand tells you something about how few of them come back, and QED still sit at the price point where most good systems begin.

Shop all QED Cables →

Specification :

  • Conductor type: Solid Complementary
  • Metallurgy: 99.999% OFC & SPOFC
  • Conductor size: 1 x 0.643 mm & 1 x 0.404 mm
  • Combined conductor cross-section: 0.45 mm²
  • Dielectric: Foamed Polyethylene
  • Capacitance: 57 pF/m
  • Self-inductance: 0.45 μH/m
  • Loop resistance: 0.050 Ω/m
  • Dissipation factor @ 10kHz: 0.00250
  • Outer jacket: Black Pearl PVC
  • Nominal outside diameter: 8.0 mm
  • QED Lifetime Guarantee

We use Royal Mail 1st Class services for our Standard Delivery.

Orders received before 4.30 pm Monday to Friday are usually dispatched the same day by FIRST CLASS post (unless premium postal or timed courier services are selected), subject to stock availability. This does not apply to custom-length cables and speaker cables as these require a longer timescale to terminate. This also excludes all cables selected for the burn-in service. Please note, we do not process orders on national holidays in the UK. Over 98% of our orders are delivered the next working day including Saturdays.

 

Standard delivery is usually within 2 working days, although 98% of all orders are delivered the next working day including Saturdays. In extreme cases, such as delivery to the Highlands and Islands, this may take 3 days.

 

All items are fully insured and come with an invoice from Future Shop. We use the Royal Mail for delivery of small packages and DPD Local or DHL for items that weigh over 2KG. Items over 2KG are fully insured and will usually be delivered within 48 hours of placing your order subject to stock availability. For international orders, we use FedEx or DHL services where customers have selected this option.

 

 

Please note, special orders for non-standard cable lengths may be subject to longer deliver time-scales. This may vary from manufacturer to manufacturer.

 

We offer 'Free delivery on orders over £99' subject to the following terms & conditions:

  • Applies only to orders with £99 or more of items (including VAT at the UK rate), at Future Shop
  • Free Delivery on orders over £99 utilises Royal Mail First Class postal service for items weighing under 2KG. For items weighing over 2KG, we use DPD or DHL next working day services which deliver from 9.00am to 6pm within mainland UK (excludes Royal Mail Special Delivery Services and timed next day delivery services by DPD or DHL).
  • Applies only to deliveries to addresses within mainland UK and Northern Ireland addresses. Applies only to orders that are to be delivered to a single Mainland UK delivery address.
  • You will not be eligible for free delivery on your order if any items are cancelled or returned for a refund, bringing the total order amount below £99. Where items are returned, the refund due will be the cost of the item less any postage costs.
  • We reserve the right to change or discontinue 'Free delivery on orders over £99 promotion at any time.
  • FREE DELIVERY FOR ORDERS OVER £99 OFFER DOES NOT APPLY TO TRADE CUSTOMERS.

 

UK Postal & Delivery Charges - FIRST CLASS

Free UK delivery on all orders over £99*

Weight Price (FIRST CLASS UK POSTAGE)
0g - 1000g £3.95
1000g - 1400g £4.95
1400g - 1800g £5.95
1800g - 2000g £6.95
2000g - 3000g £8.95


* Free Delivery on orders over £99 utilises Royal Mail First Class postal service for items weighing under 2KG. For items weighing over 2KG, we use DPD or DHL next working day services which deliver from 9.00am to 6pm within mainland UK.

Free Delivery for orders over £99 excludes Royal Mail Special Delivery Services and timed next day delivery services by DPD or DHL.

 

Special Delivery UK - Guaranteed Next Working Day

We have 99.9% of the UK covered With Royal Mail Next Day Special Delivery. We guarantee delivery to most UK addresses by 1pm the next working day. This includes Northern Ireland, Jersey and Guernsey. Some places take longer to deliver to but we still guarantee delivery within three working days by 5.30 PM.

 

Please note, Royal Mail Special Delivery for next working day may not be possible where non-standard cable lengths are ordered. If this is the case, the item will be shipped via The Royal Mail Special Delivery service as soon as the cable is custom made.

 

For orders weighing over 2KG, we reserve the right to ship items using Next Day Pre-Noon Courier Services where Royal Mail Special Delivery option has been selected.

 

Channel Islands & Northern Ireland

We accept orders from all Channel Islands including Alderney, Jersey, Guernsey and Sark. Unless you select a premium service, Items weighing under 2KG are delivered using our standard UK delivery option above. For items weighing over 2KG, a surcharge may be applied for all deliveries to the Channel Islands as well as Northern Ireland.

 

European Countries

Deliveries to EU member states are not subject to 20% VAT after December 31st 2020 and therefore the 20% VAT on items is automatically deducted when you log-in, register or proceed to place an order.

 

The customer will be liable for the VAT at the local VAT rate, duty on the import and the brokerage service fee if applicable. This may need to be paid in advance to your local Customs & Excise office or the delivery company before your order can be delivered.

 

We offer the following shipping services:

  • Royal Mail First Class International Airmail Services - Items are usually delivered within 3 to 5 working days
  • Royal Mail Standard International Mail Services - Items are usually delivered within 7-10 working days
  • DHL Express International - Items are usually delivered within 24 to 48 hours. DHL orders must be received by 3:30pm for next day service to most destinations in Europe
  • Federal Express International Priority - Items are usually delivered within 24 to 48 hours. FedEx orders must be received by 3.00pm for next day service to most destinations in Europe
  • Federal Express International Economy - Item are usually delivered within 48 to 72 hours

We reserve the right to change your shipping method without notification if you select a method that we cannot use for your shipment (for instance, we cannot ship via postal services for items over 2 Kg to International destinations). If we need to change your shipping method, we will choose the least expensive shipping method for your order.

 

Worldwide - Excluding UK & Europe

Deliveries outside of the UK are not subject to 20% VAT and so the 20% tax on items is automatically deducted when you log-in, register or proceed to place an order.

 

If applicable, the customer will be liable for the taxes at the local tax rate, duty on the import and the brokerage service fee. This may need to be paid in advance to your local Customs & Excise office or the delivery company before your order can be delivered.

 

We offer the following shipping services:

  • Royal Mail First Class International Airmail Services - Items are usually delivered within 7 to 10 working days
  • Royal Mail Standard International Mail Services - Items are usually delivered within 15 working days
  • DHL Express International - Items are usually delivered within 24 to 48 hours. DHL orders must be received by 3:30pm for next day service to most destinations in Europe
  • Federal Express International Priority - Items are usually delivered within 48 hours. FedEx orders must be received by 3.00pm in order to ship items the same day, subject to stock availability
  • Where the actual weight of the package significantly exceeds the shipping cost charged on orders, we may write to you for an additional shipping charge. For larger orders, items may be shipped in multiple packets at our discretion

We reserve the right to change your shipping method without notification if you select a method that we cannot use for your shipment (for instance, we cannot ship via postal services for items over 2 Kg to International destinations). If we need to change your shipping method, we will choose the least expensive shipping method for your order.

Write Your Own Review

QED Performance Audio 40i Digital Audio Cable - Custom Length

We are interested in your opinion of this product. let us and other customers know how you feel by filling in the comment field below. Your review will appear in this section within 3 working days.

Please do:

  • - Write 50-300 words for the product
  • - Comment on the products value and effectiveness
  • - Tell us if you like the product, but most importantly explain why you like or dislike it
  • - Mention related products and how this one rates by comparison
4.8
17 reviews
5★
14 (82%)
4★
2 (12%)
3★
1 (6%)
2★
0 (0%)
1★
0 (0%)
AI Review Summary — Generated from 17 Reviews

Customers consistently praise this digital coaxial cable for its build quality, audible sound improvements including enhanced detail and bass, and excellent value for money. Multiple reviewers report noticeable performance gains over cheaper alternatives and Toslink connections. The cable features adjustable plugs and can be ordered in custom lengths. However, a significant recurring issue is the lack of installation guidance: connectors require unscrewing the plug cover before fitting to standard RCA sockets, a non-obvious process that frustrated several buyers. Additionally, the cable's stiffness limits tight bending, necessitating longer cable runs. One delivery complaint was noted regarding a carrier. A recurring negative theme is insufficient product documentation regarding installation and cable handling characteristics.

Bernard Webster
Exceptional quality, audible improvement. 30 August 2026
High-quality interconnect that clearly improved sound quality when used with the Cambridge AXN10 and Arcam SA20. Competitive price and prompt delivery.

Highly recommended product and supplier.
TS
Excellent value for money 22 August 2026
I use this cable between my WiiM and Rockna DAC. It is well made, performs exactly as expected and offers excellent value for money.

For a digital coaxial connection, it’s difficult to justify spending significantly more. Highly recommended for the price.
Chris Holmes ✓ Verified Purchase
No information on how to fit the cable! 23 February 2026
There was no information on how to fit the cable. See another buyers notes. The seller should have put a note with the cable!!!!! Oh the cable does work.

****** As they come, they will not fit a standard RCA socket. What you must do is unscrew the plug cover, fit the plug and then tighten it again. ****
Response from Future Shop
Thank you for your feedback. The QED Performance 40i uses locking RCA connectors, which are designed to be unscrewed slightly before fitting, then tightened once inserted to ensure a secure connection. We appreciate you pointing this out and will look at making this clearer for customers in future.

We’re glad to hear the cable is working well once installed.
Good quality cable ✓ Verified Purchase
Good and cosy effective 26 January 2026
Another cracking digital cable from Future Shop, complete with adjustable plugs to ensure a good, tight connection for your components.
Eddy ✓ Verified Purchase
Good but with a twist 24 January 2026
This is a good cable (based on build quality, as I can’t judge yet on performance) at a good price, but there literally is a twist. As they come, they will not fit a standard RCA socket. What you must do is unscrew the plug cover, fit the plug and then tighten it again. As there is no indication on the plug or any note in the package, if you don’t know, you’d never guess. The only clue is that, as you can see, the connectors do look unusual. Fortunately, the support team at the store responded to my message within the hour, and all was good. They agreed that a note somewhere would help.

Finally, just a tip if you are buying your first ‘quality’ cable, as I was. The cable itself is much stiffer than you might be used to. It won’t take tight bends, so allow enough length to accommodate this.

So one star off for the lack of info. Otherwise, it would have been 5.
Alan ✓ Verified Purchase
Excellent cable 12 December 2025
Excellent-sounding interconnect; took a few days to burn in to sound its best. More detail, deeper bass than my more expensive Toslink connection....

Downside, delivery company was awful, didn't even bother to attempt to delivery ( I was in waiting all day for delivery ), they took item to local pick up point, so I had to collect.. Just wondering how many times did the driver do this, to save time..
Response from Future Shop
Thank you for taking the time to leave such a detailed review. We’re really pleased to hear the interconnect has delivered the sound quality you were hoping for once it had a little time to settle in.

We’re sorry to hear about the delivery experience. That’s not the level of service we expect from our carriers, and we appreciate you flagging it. We’ll raise this with the courier. Thank you for your patience and for sharing both the positives and the frustrations.

Frequently Asked Questions

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Write Your Own Review

QED Performance Audio 40i Digital Audio Cable - Custom Length

We are interested in your opinion of this product. let us and other customers know how you feel by filling in the comment field below. Your review will appear in this section within 3 working days.

Please do:

  • - Write 50-300 words for the product
  • - Comment on the products value and effectiveness
  • - Tell us if you like the product, but most importantly explain why you like or dislike it
  • - Mention related products and how this one rates by comparison
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