The World’s Best Audiophile Linear Power Supplies

Fidelizer Nikola2

Price: ~$750.00 (Single rail)

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Nikola2 Update

• Improved circuit board design with dual input capacitors to handle high power device better
• Upgraded bridge diode design with more powerful model from 2A to powerful 8A with heatsink
• Upgraded capacitors to provide better resolution, details and transparency while maintaining coherent natural sound

This new design will handle high-powered devices better (Roon Nucleus+, etc) and provide smoother and more powerful sound with improved resolution.

About

Balanced DC power supply

Most devices accept single phase DC input so it’s not possible to make balanced DC output. We tried building balanced AC power conditioner with full wave transformer but it didn’t work well as we hoped with increased noise from another phase. It should only be used with balanced DC power supply output only.

So, we decided to use bridge rectifier with isolation transformer and the result is very satisfying. Diode won’t work twice harder as before, DC current is even cleaner with matching design for non-balanced DC power output.

Two-stage voltage regulation topology

When we tried to to make early prototyping PSUs having cleaner sound, we also tried two-stage voltage regulation topology (not cheap transformer coil). It produced cleaner sound with smooth presentation but dynamics wasn’t as solid as before and worsened transient attack.

We also found side effects from two-stage voltage regulation with more heat dissipation from lost energy during each stage. We decided to build transformer with specific voltage output for the best results with purist design approach.

Choke-filtered linear power supply

We also tried choke-filtered design too since some of preamps I like use this design. With very clean sound and precise imaging using choke-filtered, there’s also side effects of choke-filtered making the sound losing sweet touches and full body dynamics on lower frequencies so we shot this down.

Power capacitor bank

I could vaguely guess already as I saw from products trying this approach before but we decided to try this too. You won’t get current shortage with this design but since we never has issue with current load, we decided to drop it like before.

The reason why we dropped this design is mainly about sonic performance. Focus became blurred and timing got a lot slower with strong sound signature from capacitor. No matter what capacitor brands and values we tried, it does harm more than good in our case.

We also considered other design implementations like shunt regulator design but it tends to be very hot easily so we didn’t try it with over 3A cases. It’s important to make sure the product will be safe and reliable for years to come.

Build & Specifications

• Nikola Signature is the best affordable highend linear power supply with uncompromised design and quality to bring full potentials of devices used in highend audio.
• Regulator tuned for uncolored high fidelity audio performance
• Robust 2.5mm Aluminum chassis with better vibration control
• Highend grade capacitors providing richer sound
• Furutech FI-03 Gold IEC inlet improving details and resolution
• 14 AWG made in USA pure copper internal wiring
• Wattage: 45W (70W for Nikola Signature 12-19V)
• AC input voltage: Switchable 115/230V (configured according to shipping location)
• AC input type: 2-pole+earth, rated 15A/250V with ceramic fuse
• DC output terminal: 2-pole AC-DC power connector
• DC output power limit: 3.7-5A@12V / 4A@5V / 2.8A@7V / 2.2A@9V / 3-4.6A@15V / 2.36-3.68A@19V
• Bundles: 2.0m US Power Cable / 1.8m DC power cable
• Dimension: 152 x 130 x 44 mm for Classic / 150 x 241 x 60 mm for Signature
• Weight: 2.5kg

Overview

At the time of this review, the Nikola2 hasn’t been released but I was reassured that this is what the production version will sound like.

The Fidelizer Nikola2 is one of the more musical-sounding power supplies on this list. It’s a sweet and beautiful sound and aligns with my tastes in tonality. This power supply has very nice PRaT and dynamics. Nothing stands out in a bad way. It’s just enjoyable and believable music.

For what it’s worth, I find it to be the power supply equivalent of my reference USB cable, the Danacable TruStream. One of the very few components I’ve kept and still use over the years. So chances are, I’ll probably keep the Fidelizer.

The Sound

As far as power supplies still being sold, the Fidelizer Nikola2 power supply has the best tonality and timbre in the entire lineup. It has a fantastic amount of tonal variance, soul, and essence. It’s incredibly tactile, balanced in fullness, and articulates with just enough precision. Because of that, you’re able to hear subtle timbral and cues and resonances that are usually masked by other power supplies. This is consonant with what I hear in real life.

The Nikola2 embraces rawness, smoothness, and speed. There’s an abundance of textured excitement and naturally oxygenated melodies. The initial attack is always in plain view – especially with fleet-fingered fretwork. However, there is a slight bloom around the edges, so not the last word in pristine delineation.

Soundstage isn’t the deepest but it’s not closed in. There’s still a natural continuity and blending between the elements. It’s laid back without feeling distant. Layering isn’t the best but you could still hear depth to each note. Once again, it’s more of a balance. The Nikola2 has a smaller sound rather than being a thick or thin sound.

Bass is kind of in the middle of the road. As far as quality and performance, it’s not super authoritative but has a decent amount of heft. It won’t be enough to rattle your skull – so it may be better paired with meatier and bassy gear.

The Nikola2 is undoubtedly a high-performance power supply. It has dynamic strides, textured midrange, detailed highs. In addition, it’ll be tough to beat the number of natural colors this power supply brings to the forefront.

Tradeoffs

The biggest drawback is that the music doesn’t project out with as much full-bodied presence. The strums and percussions don’t throb with heavy force or weight. It just doesn’t have the mass and density as some of the others. So it does lack a bit of tactility or a huge soundstage. In other words, it doesn’t come out and grab you by the collar.

Treble isn’t the most brilliant, but very natural in its shine. Bass isn’t the most forceful but isn’t the worst. Consequently, drums and cymbals sound a tiny bit mellow. There isn’t a lot of splash or grunt. You don’t feel the impact but could still appreciate the amount of body that does make it through.

Who Should Buy the Fidelizer Nikola2?

Die-hard tone snobs will enjoy the Fidelizer Nikola2. It’s rawer than it is smooth. It’s more lightfooted than it is dense. But it’ll have an enormous amount of tonal perspective across all genres of music. There’s an even sense of natural transparency and musically arresting energy. Brass has more of that sonic stretch and strings and percussions are played with charming cadence.

Comparisons

vs. Sean Jacobs DC4

• DC4 sounds more real from a physical sense, but the Nikola2 sound more real from a tonal perspective.
• The DC4 is technically superior in all aspects.

vs. Paul Hynes SR7

• SR7 sounds more real from a physical sense, but the Nikola2 sound more real from a tonal perspective.
• The Fidelizer has far more natural tonality.

vs. Mojo Audio Illuminati v3

• Nikola2 has much better focus and precision.
• Both they both have a slight bloom around the outlines.

vs. UpTone Audio JS-2

• The JS-2 is quieter.
• The Fidelizer is not as elevated but has more control.
• Fidelizer has a more natural tone.

vs. Plixir Elite BDC

• The Nikola2 has better tone.
• Elite BDC has more resolution and depth.
• Elite BDC is more full-bodied.
• Elite BDC has far better layering.

vs. JCAT Optimo 3 Duo

• Optimo 3 Duo has a more soulful and denser midrange.
• Nikola2 has truer tone.
• Nikola2 is more raw and has better detail retrieval

vs. HDPLEX 300W

• The Fidelizer is in some ways a smoother HDPLEX with better tone.

vs. Paul Hynes SR4-12

• SR4-12 has better tone but Fidelizer has better focus, imaging, and darker background.
• If these two had a baby, it would be perfect.
• Fidelizer has better transient clarity
• SR4-12 is fuller and warmer.