Sean Jacobs DC4 Linear Power Supply

Price: $7,500

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Sean Jacobs on the DC4

The DC4 is our ultimate PSU, borne from over a decade of high-end audio PSU expertise. This is the true cost-no-object concept PSU that clients keep asking us for, and it is finally here!

The DC4 uses a larger case than the DC3, and the DAVE model is fitted with 3 output rails to fully power the Chord DAVE DAC. Note that we cannot combine other outputs for other devices into this case, it’s a standalone dedicated DAVE PSU with no option of adding anything else.

We get a lot of emails asking about “double regulation”. Please note that *ALL* of our PSU designs (including our Naim Audio PSU range) are effectively double regulated *AS STANDARD*. Our regulator module design actually delivers around 8-10 times less noise than if you had two single-regulated versions of our circuit in simple series. We gain little advantage in performance by connecting two of our double-regulated modules in series, and there are downsides of increased heat dissipation and extra space needed, hence we have never offered this as a mainline option. But if low noise is the most important factor, we can offer two regulator modules in series as a bespoke upgrade option.

The DAVE DC4 has been a lot more popular than I would have ever expected. To the point where well over half of all DC4s in existence are for the Chord Electronics DAVE. And whilst every DC4 is custom built, the configuration of a DAVE DC4 is fixed (ignoring options like front panel colour, output cable length, Neotech or Mundorf wiring etc). In addition, we sometimes do tweak a few designs slightly to be more suited to certain “problem” devices (i.e. low/high current draw devices will be treated differently). We also consider whether it’s drawing a steady current or pulses/spikes of current over time, whether the device generates considerable RFI through its DC input socket, etc.

Build & Specifications

  • Dimensions: 450 mm x 290 mm x 155 mm (W x D x H, with IsoAcoustics Gaia feet)
  • Furutech gold-plated IEC inlet for mains AC supply
  • Custom-made ultimate specification toroidal transformer (600VA for a DAVE DC4) with multiple shielding layers, fully enclosed in a stainless steel shell for additional shielding and noise suppression. Vibration isolation mounting system is used to eliminate chassis vibration which can affect the regulator circuitry.
  • The new PCB is 2.4mm thick for additional rigidity and is gold-plated. Low-noise Schottky diodes are used for rectification, and the reservoir Mundorf capacitors.
  • The entire DC wiring loom is made using Neotech OCC wiring with PTFE insulation
  • The DC4 regulator module also contains our new “CX” module – this acts to drastically reduce incoming DC noise from the reservoir capacitors, by factors of up to around 1,000 at low currents.
  • DC4 regulator modules can supply up to 5A continuous current as standard
  • Full set of Vishay Z-foil “naked” resistors for the regulator section, and extremely low noise resistors for the (non-critical) CX section and for one filter network of the regulator itself.
  • The CX module section uses the same Nichicon FG “Fine Gold” capacitors as the DC3 design, as we found that the KAISEI capacitors made no noticeable difference here.


The Sean Jacobs DC4 is primarily used with the Chord Electronics DAVE as a direct “plug-n-plug” replacement for the internal SMPS. The inclusion of this power supply into this review was due to requests from the audiophile community. Sean Jacobs is an acclaimed designer and known for, among other ventures, building power supplies for some of the Innuos flagship music servers. Both Sean and Vassil were kind enough to make me an adapter cable for the 5V output – solely for the purposes of this review. The DC4 wasn’t meant to be used in this type of application, so please keep that in mind.

To sound its best, the Sean Jacobs DC4 takes three months to break in. Unfortunately, I only had a little over a month with the DC4. But I believe it was a decent amount of time to get a decent idea of what this power supply is capable of. If I were to extrapolate, I would think it would sound more open and perhaps more detailed if it were given a few more months.

Dense Bodies

If I were to describe the DC4 in two words, it would be “persuasive embodiment.” If you want to not only feel your music but grasp the corporeal presence of all the performers and instruments, this power supply is second to none. It does this better than even the Paul Hynes SR7. Until the DC4, I’ve never heard of a power supply that could shape out the curvatures and material of a recording with such authenticity.

Usually, when the music is this molded, there’s a sense of “over contouring” across all elements of a recording. They all seem to have the same amount of weight, smoothness, and gravitational pull. Consequently, brass and wood seem to have been made with the same material. Which obviously sounds unnatural. But this is not the case with the DC4.

The Sound

The DC4 is able to provide adaptive lifelike dimensionality. Each actor preserves its own density and acoustic influence. Higher-pitched sopranos have a different amount of acoustic occupancy over more baritone ones. A piano placed further back in the soundstage will have lesser weight and a lighter decay than a bass being played six feet in front of it. Even reverb and decay push out – and fades truthfully.

Depending on the type of instrument and where they are in the recording space, you could hear the differences in space – and the directionality of the resonances. Soundwaves only come from where there is sound…and is quiet otherwise. This is very impressive as none of the other power supplies can do this at this magnitude.

Consequently, the background is pitch black and imaging is naturally focused and positioned. Assertive punch or impact is only dished out at the amount called for and not a “blanket” amount of force. Each part of the recording is isolated yet interacts with the rest of the players in a very wholesome and harmonic way. It’s like having the person in front of you but isn’t done with a heavy hand. For example, in Corey Gray’s Maps (Acoustic), there’s a clear distinction in how congealed the female and male vocals are in space. Their presence is carefully crafted to sound very natural.

Gradations in Density

Here’s another example, The Ventures’ The Lonely Bull. Pay attention to the drums on the right, trumpets and female vocals to the left, and strings and vocals at the center. They each throw their weight in an organic and realistic way. You could imagine the thickness of strings and the size of the instruments. This distinction could also be grasped from Dylan Ryche’s Playtime. This variance in the density and its ability to articulate these natural differences makes the DC4 stand out from the rest. You could just walk into the music.

The DC4’s ability to convey variations in density is enormous. How much of the music you feel depends on the design and composition of the actual instrument or technique of the artist. A ukelele and an electric guitar have a different sense of presence and thus – control the space differently. Another strength is in bass detail. You could hear the actual instrument bending and resonating.

vs. Stock DAVE power supply

The stock power supply has more rawness and color to the sound. Surprisingly, I was also getting more bass out of the subwoofer as well. It’s more textured and fibrous while the DC4 is more gel-ed and solid. The stock PSU comes off a bit more aggressive and brittle…and more digital. Whereas the DC4 is heavier, more present, and much meatier.

The DC4 basically solidifies the sound, adds a coat of smoothness, and changes the color to more of a grey than a golden warm hue. It prioritizes a real sense of presence by separating out each piece of the music into a convincing 3D object. Although the DC4 does sound more “real,” the stock PSU has a truer, more organic tone. But it has nowhere near the contour, molding, or dimensionality of the DC4. It can’t produce or build out the soundstage in a convincing way. But the stock PSU does have more vibrance, air, and crunch. You trade the solidity and depth of the DC4 for more soulful coloration with the stock PSU.

To conclude, with the DC4, it’s just more physical and you feel the music more. Which makes its impression of the real thing undeniable. It’s much like going from a 2D cartoon and a live-action movie. There’s more aural perspective.


So typically, when you have this much body to the sound, the tradeoff is usually tone and texture. Luckily the oiled-skin effect is kept at a minimum. But the tone is more grayscale and colorless. So if you prefer something more neutral, this won’t be an issue. This actually goes along the lines of Sean Jacob’s design philosophy of having everything uncolored. He believes the coloring should be done at the amplifier stages.

As far as the top-end, there isn’t a lot of air or brilliance. So strings will have a thicker, duller flair to them. Which gives you the impression that instruments are played closer to you. Transients aren’t the speediest and outlines aren’t the most focused…but that plays into the more analog and cohesive sound the DC4 imparts.

Who Should Buy the Sean Jacobs DC4 Power Supply?

The DC4 sounds like a true-to-life hologram…in grayscale.

Overall, the DC4 has a sound that is “closer to the microphone” and makes the listening experience more immersive. In a word, it’s “believable.” It’s able to form all the subtleties and offer a natural sense of transparency. From Lorde to Hendrix, this is the most (weighted) three-dimensional listening experience I’ve had. There’s depth, thickness, and technique without any signs of digital. The harmonies are accurately overlapped and congealed. And the talent never gets lost no matter how complex the recording is. The DC4 is the last word in grip and control. It perfected what it would feel like to have the band in your listening room.

You should buy the DC4 if you enjoy a neutral sound and don’t mind a more shelved top-end. The DC4 is not tonally variant and does not sparkle or have a lot of air. Bells and shakers don’t really radiate with bling or zing. Personally, I would also prefer a bit more rawness and color. Aside from that, it is the most “real” sounding power supply in this review. There isn’t a single hint of digital or harshness that breaks the illusion of having the performers in front of you.



  • Effortless variance in density while keeping background pitch black.

  • The BEST at acoustic molding. Performers sound real.

  • Gradations across the entire spectrum. Especially bass.

  • Clean, smooth, and analog sound

  • Very physical and tangible

  • 100% analog sounding

  • The soundstage isn't confined or limited

  • Not very fiborous

  • Not a lot of sparkle. Perhaps another 2 months would've opened it up. To be continued...

  • Tone is more neutral and colorless

  • Some lower level textures are smoothed over. A slight gloss over the denise bodies.


vs. Paul Hynes SR7

  • DC4 has more 3D realism and articulates better than the SR7.
  • SR7 has a speedier more vibrant sound. The DC4’s top-end is much duller.
  • Both have similar tone.
  • DC4 has more bass output.
  • SR7 has more flair and air while the DC4 is heavier and more melodic.
  • There’s more balance in clarity with the SR7 and more form with the DC4.

vs. JCAT Optimo 3

  • These are two very different power supplies. The Optimo 3 is darker in tone and more generally articulated. While the DC4 takes the realistic molding to another stratosphere. The kicker is that the Optimo 3 does have a more natural tone, albeit darker gray.
  • Optimo 3 has heftier bass but the DC4 has more low-end gradations.
  • DC4 is technicaly superior – by a large margin. Imaging, depth, soundstage, contouring, detail. The Optimo 3 has more of a “coating” for easy listening.