AC-2K BALANCED MAINS SUPPLY
Balanced mains power for lower noise floor, more detailed and natural sounding audio and A/V quality.
The AC-2K Balanced unit from connected-fidelity™ is not just another form of mains power cleaning or ‘noise control’ treatment. It is a fundamentally different approach.
What will you hear with the AC-2K balanced unit installed?
The music will sound significantly more natural, digital sources flow more musically, the space around instruments and the 'holographic' impression of the musical stage will grow. The silences in the music will seem blacker because the noise floor has dropped. With A/V equipment, improvements in depth of colour with clearer images are to be seen.
The AC-2K is a system upgrade unlike any other.
Balanced mains power works like balanced signal lines, there is a very low noise floor due to the cancelling out of 'noise'. Both balanced mains and balanced signal lines are used extensively in recording and radio/TV transmission studios to offer the lowest noise floor. The benefits of this approach used in professional installations is now available for home audio and AV systems in a form best suited to home audio and A/V.
When balanced power drives your home audio or A/V equipment:
1. The transformers in your equipment work more efficiently, so offering the very cleanest power source to both analogue and digital audio electronics.
2. Partial isolation of the incoming Live and Neutral mains lines, so there is a degree of ‘conditioning’, with reduced DC entering the balanced supply.
3. The earth output is not carrying any AC/DC 'noise' often found on the home earth line. ‘Noise' from EMI/RF is not picked up in your power cables and entering the audio signal path.
4. Power cables from the AC-2K to your equipment are less critical. That is not to say that better cables might improve sound quality, but fundamentally the RF and other noise usually picked up from un-shielded mains cables is cancelled out, so more expensive shielded cables become unnecessary.
Every aspect of the AC-2K is designed for high quality home audio and A/V use.
Balanced power can be used to power some or all your equipment. The most beneficial effect is heard powering the lower signal level analogue and digital equipment, like DAC's, CD players, streamers, phono-amplifiers, pre-amplifiers etc.
We do suggest you use the AC-2K unit to power all your audio equipment, including power amplifiers up to 1,000W alongside your other components, up to a total of 1,600W. More powerful amplifiers, such as those used in AV systems, may either be connected directly to a second wall socket or from a second AC-2K unit, further isolating it from the rest of your audio system.
The Reference AC-2K balanced mains unit is designed to be situated in the listening room connected to a mains wall socket, the balanced output then taken to your components.
You can use your existing distribution block with any passive ‘noise’ controlling components it may include. We do recommend our Six Star distribution block, a star wired block offering identical impedance to each of its 5 outputs, for the lowest noise floor.
The AC-2K range design:
The AC-2K is broadly a ‘fit and forget’ component so you can enjoy the highest quality sound from your audio or sound and vision. The design employs best practice ‘audiophile’ engineering techniques and treatments.
ALL power components, including the transformer are deep cryogenically treated to improve output efficacy, ensuring maximum power delivery and ‘speed’. After the cryogenic treatment, the transformer performs like a far larger non-treated transformer, offering better bass articulation, natural tonality and micro-details.
Inside the resonance damped non-magnetic casework there is anti-surge protection (not in circuit when powered up). This 30 Amp electronic double pole power switch activates after the massive 2.0Kva transformer has powered up, ensuring no fuses are ‘thrown’ in your home, when the AC-2K is switched on.
The input and output sockets are proven designs, chosen for their power transference qualities, further improved by cryogenic treatment, as is the specially developed internal mains wiring.
There is a switchable power supply voltage monitor on the front face showing the balanced power output voltage.
The entire range of AC-2K balanced power units can be supplied with either a 1/1 ratio input/output, so the balanced output supply is the same voltage as the input; or with a 10Volt output reduction transformer. In all other respects identical. It is advisable to read our discussion paper on this subject, or ask for advice from your AC-2K Dealer or us, to confirm the optimum voltage selection for your circumstances.
The entire range can also be fitted with a double pole Residual Current Circuit Breaker with Overcurrent Protection (RCBO) on the balanced output side. This ‘safety’ option is not strictly necessary, but if you have any concerns regarding potential failure of anything supplied with power from your AC-2K, this re-settable ‘fuse’ will shut down in the event of a component failure. An RF filter can also be fitted on the input side. This removes RF from the incoming mains supply, and has been shown to improve sound quality, particularly in environments where there is a high degree of RF contamination.
AC-2K ranges and options:
The AC-2K ‘Studio’ range are primarily designed for use away from the critical listening room, or placed in a cupboard. The Studio is our entry level AC-2K, using the same cryogenically treated 2.0kVA transformer.
The Studio is offered with a single UK output socket option. Supplied with a brushed Silver fascia, and printed face plate.
The AC-2K ‘Reference’ range has been designed for use alongside your audio or AV equipment, in the listening room. The transformer is mounted internally on a substantial non-magnetic anti-vibration platform, electro-mechanically isolating it from the body casework - and your room.
There are the options of Silver or Black fascia plate, and the brass printed face-plate brings visual appeal.
There are one, two or three UK output options available, 1-4 outputs for Schuko (EU) and US sockets. The UK three way and Schuko / US 3 and 4 way outputs are star wired in the same way we star wire our ‘Six Star’ distribution block, offering identical impedance to each output.
The AC-2K ‘Reference with WireWound technologies’ balanced power unit takes the Reference design to a higher fidelity level.
Our unique design WireWound technology is utilised between the power input socket and transformer, offers a cleaner, quieter, and more dynamic balanced supply output. Offered with the 3 x UK sockets, and 4 x Schuko or US socket options.
Additional components:
AC-2K Power cables. We do not supply a ‘kettle cable’ with the AC-2K, because it adds unnecessary cost, and is not an appropriate quality power connecting cable. Instead, we offer one of our Unity power cable range at -40% off the full retail prices, if required. You may wish to continue using your own choice of power cable.
AC-2K Isolation platform. A vibration isolation platform, utilising four of our Connected-Fidelity ‘Float’ pucks, secured within a bamboo plywood platform, sized to suit the AC-2K. Two options, to sit on either a carpeted or flat surface. It brings further improvements to the to the performance of the AC-2K, and your musical fidelity.
Through extensive listening tests we are sure our AC-2K range comfortably outperforms other similar balanced power products on the market, due to our design and cryogenic treatment of all power components, particularly the transformer.
Sold through our UK Dealer network, this offers you the chance to hear the dramatically increased fidelity an AC-2K brings to any audio or AV system; a home demonstration might be available. A two year guarantee covering faulty materials and construction is offered.
AC-2K ‘Studio’ version
AC-2K Studio 1* x 240V** out
AC-2K Studio 1 x 230V out
AC-2K Studio 2 x 240V out
AC-2K Studio 2 x 230V out
AC-2K ‘Reference’ version
AC-2K Reference 1 x 240V out
AC-2K Reference 1 x 230V out
AC-2K Reference 2 x 240V out
AC-2K Reference 2 x 230V out
AC-2K Reference 3 x 240V out
AC-2K Reference 3 x 230V out
AC-2K Reference 4 x 240V out (Schuko and US only)
AC-2K Reference 4 x 230V out (Schuko and US only)
AC-2K ‘Reference’ with Wirewound Technologies version
AC-2K Reference WW 3 x 240V out
AC-2K Reference WW 3 x 230V out
AC-2K Reference WW 4 x 240V out (Schuko and US only)
AC-2K Reference WW 4 x 230V out (Schuko and US only)
ADDITIONAL OPTIONS (all models)
RCBO electronic output fuse
RF Radio Frequency input filter
Isolation platform
Notes:
Input IEC power socket is C19 (16A) type
* refers to number of output sockets
** refers to voltage output, assuming 240V input
Product Size / Weight
UK options: 330mm Deep x 230mm Wide x 180mm High
EU/US options 355mm Deep x 230mm Wide x 180mm High
Net weight 16.5Kg – 17.00Kg Subject to specification.
Reviews
-
The Ear, Reviewer: Chris Frankland 18.09.2026
I listened to many more of my favourite albums and CDs than there is room to mention here, but they left me in no doubt that the Connected-Fidelity AC-2K Wirewound is a seriously worthwhile addition to a system. Its effect is also fundamental and the difference it makes should not vary wildly from system to system in the way that some speaker and interconnect cables will suit certain setups but not others.
In my system, it put more space around each musician and let me appreciate better what they were playing and how they complemented each other. It gave the music more life, impetus and dynamics and presented it in a more coherent way. It was a significant improvement – as big an improvement as you might expect from upgrading one of the major components in your system. I recommend it wholeheartedly.
Tighter, deeper bass
Cleaner, more defined percussion
More focused, natural-sounding vocals
Better reveals playing technique and instrument detail
Easier to follow individual instruments in complex mixes
More rhythmic cohesion and flow
Balanced, passive, star-earthed design (no active noise circuits)
Benefits should be consistent across different systems
(review link) -
Hi-Fi+ Editors Choice 2026
-
The Ear
“The Connected-Fidelity AC-2K and Six Star/Unity Power Two setup delivered far more than I was expecting. The differences between it and the standard mains block were huge and musically very significant. You could simply hear far more of what was being played and how, with instruments taking on their proper context in the mix... With the Connected-Fidelity AC-2K balanced supply and [Six Star] distribution block, the differences transcend mere tonal balance and what you get is a real musical improvement across the entire frequency spectrum, which should be the case in any system... What this showed me is that the quality of mains fed to your system is important and that it is money well spent to make sure it is as good as you can get it. I recommend this Connected-Fidelity setup wholeheartedly.”
(review link) -
Hi-Fi+
“He concluded his review by saying, “Balanced mains from the AC-2K must count as one of those one-way dems, where the sonic benefi ts make switching back to the old normal an unwelcome journey. It offers cleaner, more highly resolving sound along with a mid-band declutter, without any fundamental cramping of pace and dynamics.”
(review link) -
Paul Rigby, The Audiophile Man
“What I liked about the AC-2K was that, firstly, it improved the entire frequency spectrum with one flick of the mains switch. Everything was enhanced, from top to bottom. Everything. There were no trade offs here, only positives. Secondly, the inclusion of the AC-2K was tantamount to a major component upgrade because, well, that’s exactly what it is. It’s feeding the entire hi-fi system with low noise, cleaned-up power. Grab yourself an AC-2K and, in my book, that will be money well spent.”
(review link) -
James Michael Hughes, Stereonet
“It will really help you get the very best from your hi-fi. But be warned; once you hear the improvement it delivers, you may have difficulty listening without it. That's the situation I find myself in at the moment. Oh dear!”
(review link) -
Ken Stokes,Hi-Fi Pig
"Having lived with this unit for the best part of a month its effect is addictive. I really don’t want to remove this from my rig, it is plain enough what it does once removed. I’ve unplugged and plugged back so many times I’ve lost count. A real reflection that these units work. Every time I unplugged I couldn’t wait to plug back into my system! It seems I am now used to a new ‘normal’ sound quality, a new level of realism, a new depth and soundstage, a new vibrancy to everything I play. Matters not if my source is my CD spinner, streamed or ripped files, everything is benefiting! This unit grew on me and I became addicted to what this brought to my system – a new level of transparency and detail, greater depth and width to the soundstage. I love it and I’d urge others to try. I don’t want to return this unit which I think speaks volumes."
(review link) -
Reviewer: Noel Keywood, Editor Hi-Fi World, Sept. 22
5 x 'worlds' & 'OUTSTANDING - amongst the best' award. Sound quality: .... the AC-2K smoothed and deepened the sound stage, putting space between instruments ... The performance took on greater focus and insight ... it was a riveting experiance: I could not be anything other than deeply impressed. What I was not expecting - and hit me straight away - was profound bass power and resolution. ... The opening up of the low end helped bring atmosphere and strength to the performance generally. ... its impact on sound quality, even in my city location with clean incoming supply was subtly wonderfull. For this alone - its ability to to make me want to listen - I have to give it full marks. Verdict: Subtle yet deep improvement to sound quality. Impressive.
-
“What I liked about the AC-2K was that, firstly, it improved the entire frequency spectrum with one flick of the mains switch. Everything was enhanced, from top to bottom. Everything. There were no trade offs here, only positives. Secondly, the inclusion of the AC-2K was tantamount to a major component upgrade because, well, that’s exactly what it is. It’s feeding the entire hi-fi system with low noise, cleaned-up power. Grab yourself an AC-2K and, in my book, that will be money well spent.”The Listening: The music sounded ever so slightly cleaner, giving a sensation of things being a little closer to me as if I was more immersed in the mix. The classic synth-pop of New Musik’s Churches, for example, was slightly fresher and punchier, with a subtly better sense of rhythm and drive. Tonally, things sounded fractionally brighter yet less harsh. ... Capturing the Flag by The Long Ryders – a great eighties Byrds-influenced indie rock band – was a touch more propulsive, with better detail to the guitar work and a more immediate feel to the vocals.
Some Customer feedback
‘wanted to let you know how pleased I am with the AC-2K and it has made a significant improvement to the sound on my system. There is an authority to the music that wasn’t there before.’
Extract from Customer email, details held on file.
‘I just wanted to let you know that the AC-2K has made a profound difference to my enjoyment of my system. I am actually quite shocked at the scale of the improvements, given the level of mains conditioning I already had in the system. I think the previous devices are still making a contribution and perhaps allowing the AC-2K to perform optimally in my environment. If I was starting afresh the AC-2K would be the first unit I would install, perhaps even before purchasing the source and amplification (if that makes sense)!’
Customer email, details held on file.
‘A year ago after some email correspondence with you and the loan of a demo unit from Saj at Audio Venue, I purchased the [Reference] AC-2K and Chronos cable from them.
What a great investment for my musical enjoyment it has proved to be. It has fully delivered the claims made for it, and in the professional reviews which I have also read. I think that anyone considering an upgrade to their system should start by installing your balanced unit. Having that appliance at the head of the chain audibly enhances every other unit in the chain.
The early impressions were positive, and the longer term bedding in and increase in musical pleasure makes it a compulsory purchase for any serious listeners in my view.’
Cheers and thank you, EH
04.06.2023
customer details held on file
‘Hi Michael, I am thoroughly enjoying the 2 x AC-2K's in my system. I have one serving 2 x D'Agostini Mono Block amplifiers and the other serving all my front end components. I have to say I would not be without them, I have a much cleaner sound top to bottom, it is not a cold sound but a very musical sound and a joy to listen to. I also have that "thump" in the chest with separately identifiable bass lines and it is coming out of complete blackness. The speakers are Wilson Alexandria XLFs and the digital is the Esoteric Grandioso stack. I have no hesitation recommending the AC-2K, I thought it would be good but it is much better than expected. I tried a number of different power cords and while I had improvements straight away, I went ahead and tried my top power cords and the improvement was very obvious indeed with all the previous improvements multiplied, so my recommendation is use your very best power cords to feed the AC-2Ks. I wish you continued success and thank you for putting up with my earlier impatience!’
J.H. Details held on file.
‘I am amazed that the balanced mains transformer has so markedly enhanced the sound of my system which plays through occasionally lean-sounding full range single driver horn loudspeakers. There is satisfyingly more middle and bass weight and impact, more of everything, in fact, and nothing negative. I am very happy with the unit.’
Extract from Customer email, details held on file.
‘The AC-2K is well, just brilliant. You are dead spot on, digital performance has erupted into a superb sound-stage outside of speakers and front to back. Clarity, voice and ALL instruments are clearly defined and separated. The whole frequency range has blossomed. Stunning. BETTER still for me, the Vinyl side has equally improved, and I think actually more than CD.Noise from the tranny is miniscule, so no bother there either. All in all excellent. Thank you so much, really mean it - thank you.’
Customer details on file
