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Passive ground/AC filter


Manufacturer: VERICTUM
Price (in Poland):
• 5120 PLN – including plug
• 4899 PLN – no plug

Contact: ul. Roździeńskiego 11
41-306 Dąbrowa Górnicza | Polska


Provided for test by: VERICTUM

passive EMI / RFI ground filter is something like a "black box", at least from the reviewer's point of view. "Black box" is a term defined as a a device, system or object which can be viewed in terms of its inputs and outputs (or transfer characteristics), without any knowledge of its internal workings (definition according to "Wikipedia") HERE). In the case of ground conditioners (interchangeably I used the "ground filter" term), it is justified because their composition, internal design, and so on are almost always a corporate secret. Only the results of their operation are available to us.

In „High Fidelity” we reviewed several products of that type, always finding them interesting and doing a good job for the system. First there was the X Bulk (4200 PLN) by Verictum, next the Acoustic Revive RPC-1 (11 900 PLN), Qualia physic Q1 (around 1600 PLN) and finally the QAR Earth Ground Energy S-15 (2700 PLN). Even before that some manufacturers, such as Entreq and Nordost offered similar products.

Each of the reviewed filters introduced different changes to the sound, but they also share some features, such as: "quieter/darker" background, calmer presentation of what was going on under the music. In turn, they differently "edited" the tonality of the system. Their impact was very clear, and I could hardly find any explanation for why wouldn't they work in different systems. After many years of experience with this type of products, I can say with certainty that if they are properly designed and properly connected to the system, they will modify its performance.

The X Bulk Gold is a new version of the X Bulk filter, which we tested in June 2015 - it was the first Verictum product I ever encountered (X Bulk cost 4200 PLN, now X Bulk Gold costs 4899 PLN, both versions without power plug). I truly liked its shape, make and last but not least, its performance. Since then a lot has changed, studies on passive filtering are still rolling, delivering measurable results, so Verictum has come up with X Bulk development versions - the corresponding X Bulk Silver, directly connected to the devices, and the new X Bulk Gold model to work with power distributors.


The X-Bulk, which was reviewed in "High Fidelity" in 2015, was later equipped with optimized filters, yet more effectively shielded from external interference, which is also largely resin-based. It contains, in our chosen proportions, a patented, advanced shielding, originally invented for industrial applications by one of our co-workers, a prominent Polish scientist who created several patented solutions. The specific version of this shielding we use has been modified according to our specifications and in terms of the frequency range required by X Bulk.

The new X Bulk Silver features a completely new, designed for us and made entirely on CNC machines, housing. It is still made of merbau wood, this time made entirely using CNC machines. Apart from changes in its appearance it also gained more than 0,6 kg weight, has a slightly higher resin content and has a different stress distribution, which translates into even better vibration damping.

The X Bulk Gold is different from the Silver model, because it is dedicated to the power distributors and is designed to eliminate interference through PE protective wires. That's why its filters are designed for higher efficiency - it has to cope with a greater "load" than the amount of noise of a single device, which is a job of the X Bulk Silver.

The X Bulks are sensitive to the kind of surface they are placed on, reacting to it in the same way as any classic device. They should be placed minimum 20 cm from power cables and other cables. Keeping this distance is very important! We allow testing of all our product in customers' systems, including X Bulk, for 18 days.


The X Bulk Gold is a passive ground conditioner and passive AC power supply filter in one (depending on how it is used) that is used to improve the performance of all components connected in parallel. It is delivered with the Furutech FI-E11Cu plug, that should be plugged into the power strip; this version costs 5120 PLN. It is also available without the plug, same as the X Bulk Silver – in this case user can use plug of his own choice or connects it directly inside the strip. X Bulk Gold without a plug costs 4899 PLN.

X Bulk Gold does not feature a mixture of piezoelectric minerals, but rather uses special completely passive EMI / RFI noise absorbing passive modules designed by Verictum. They are based on self-developed filtration technology. Let me remind you that the Acoustic Revive filter is also not a "mineral" one and is based on passive components such as resistors, coils, capacitors. An example of "mineral" filter is QAR Earth Ground Energy S-15.

The X Bulk Gold modules are frozen in nitrogen to -196 C in a specially developed process. The conductor connecting it to the power strip is made of 4N silver with cryogenic treatment. The silver cable, due to metallurgic processes and proper cryogenic treatment has great conductive properties which is very important for draining the interference to the filters.

The cable itself and the modules inside the X Bulk are effectively shielded from outside interference to prevent their impact on the filter. Failure to eliminate external interference would result in significant reduction and impairment of effective EMI / RFI elimination, and would adversely affect the sound. The filters are permanently immersed in resin, which also acts as a vibration damping element. Wooden, nice-looking X Bulk housing is oiled.

You can read more about company's philosophy and their other products in the article “The Magic of a System” – Verictum COGITARI + DEMIURG + X BLOCK + X BULK**.

The X Bulk should be plugged in a free socket in the power strip, same one you use to power your audio system. The filter must work for at least 12 ours plugged into a power strip for optimum filtration efficiency, optimally 24 hours. If you want to see how the sound quality changes after removing X Bulk, you should wait 5-15 minutes, it takes a while sound sound to “worsen” again. Right after the X Bulk is removed, there is no big sonic difference, the degradation of the sound is gradual and very slow until it returns to the state without any filtration.

That's what manufacturer has to say about it. I would also like to remind you that also Qualia physic, and Mr. Ken Ishiguro (Acoustic Revive) make the same recommendations for their respective products. Each of these three companies come from a different country, works independently and their products differ from each other. And yet, they all put up the same thesis: passive mass filters need time, at least 24 hours, to start working at their full capacity. It seems that this is a universal *truth**, because it has been experimentally tested in several different research centers.

These recommendations also mean that the classical A / B / A comparisons wouldn't work, but only A / B, and with a dozen minutes pause between them. The X Bulk Gold was reviewed in this way. In 'A' mode it was plugged into the Acoustic Revive RTP-4eu Ultimate power strip, placed on the Asura QAR L1 platform. The strip was connected to a Furutech wall outlet with a dedicated power line leading to a separate HPC fuse. The X Bulk Gold stood on the anti-vibration RST-38H platform. Listening was conducted as the A / B comparison, with A and B known. The interval between A and B listening was 15 minutes, as recommended by the manufacturer. The comparison was done three times.

VERICTUM in „High Fidelity”
  • TEST: Verictum DEMIURG - power cable
  • TEST: Verictum X FUSE – fuse
  • AWARD | BEST PRODUCT 2015: Verictum X Block – passive EMI/RFI filter
  • TEST: Verictum X Block – passive EMI/RFI filter
  • TEST: Verictum X Bulk – passive ground EMI/RFI filter

  • Recordings used for the test (a sele- ction)

    • Andrzej Kurylewicz Quintet, Go Right, Polskie Nagrania „Muza”/Warner Music Poland 4648809, „Polish Jazz | vol. 0”, Master CD-R (1963/2016);
    • Aquavoice, Watermusic, Zoharum Records ZOHAR102-2, 2 x Master CD-R (2015);
    • Ariel Ramirez, Misa Criolla, wyk. José Carreras, Philips/Lasting Impression Music LIM K2HD 040, K2HD Mastering, „24 Gold Direct-from-Master Edition UDM”, Master CD-R (1964/2009)
    • Bogdan Hołownia, Chwile, Sony Music Polska 5052882, Master CD-R (2001)
    • Duda, Kanaan, RudĽ, 3C, Soliton SL 719-2, 2 x Master CD-R (2017);
    • Nat ‘King’ Cole, The Nat King Cole Love Songs, Master Tape Audio Lab AAD-245A, „Almost Analogue Digital”, Master CD-R (2015);
    • NOVI, Bossa Nova, Polskie Nagrania „Muza”/Warner Music Poland 4648858, „Polish Jazz | vol. 13”, Master CD-R (1967/2016)
    • Röyksopp, The Inevitable End, Dog Triumph DOG013CDW, „Promo | No. 25”, CD-R (2014)
    • The Oscar Peterson Trio, We Get Request, Verve/Lasting Impression Music LIM K2HD 032, K2HD Mastering, „24 Gold Direct-from-Master Edition UDM”, Master CD-R (1964/2009)

    Japanese issues available at

    Bez filtrów masy można żyć – chciałoby się za klasykiem powiedzieć. Zaraz trzeba by jednak dodać „mieć system suchy jak orzeszek”… Ale od pocz±tku. Słuchaj±c kolejnych propozycji tego typu można doj¶ć do wniosku, że to szczególny typ produktu, działaj±cy na innej płaszczyĽnie niż – nawet – listwy zasilaj±ce, kable itp. Wpięty w system, po odczekaniu wymaganego czasu sprawia, że chce się słuchać muzyki czę¶ciej niż przed jego wizyt± w naszym systemie; zarówno muzyki nowej, jak i tej, któr± mamy od lat. Ale kiedy go wypniemy i przez krótki czas pozwolimy nam się przyzwyczaić do innego sposobu prezentacji, pod warunkiem, że lubimy dĽwięk naszego systemu, zapominamy o TAMTYM dĽwięku.

    One could live without ground filters. But you have to add "and have a system sounding dry as a peanut"... But lets start from the beginning. Listening to this type of products one can conclude that this is a special type of product, operating on a different plane than - even - power strips, cables, etc. When plugged into the system, after recommended waiting time, you might want to listen to music more often than before, both new one and the one you already know very well. But when you unplug it and allow yourself to get used to another way of presentation, provided that you like the sound of our system, you shall forget about THAT sound.

    I can not explain this phenomenon. All the more that after plugging in each new product of this type I tend to contemplate my own state of mind from just before I did plug it in when I thought I did not need such a product in my system. The changes improvements to the sound are THAT significant. With many other products, even very good one, it is different. Once I forget about their beneficial influence on the sound, the return is not always equally enthusiastic and often I am able to execute better judgment and being more critical this time. Often some elements of the performance start to bother me, I mean ones I have not previously paid attention to, when “suffering” chaos caused by endorphins. And it also often happens that I miss them, unable to imagine my life without them.

    It was no different with X Bulk Gold. It's a product that always brings positive results, plugging it in again always was a good thing. I can't say it was highly anticipated one, but - see above. The reviewed filter causes the sound to get richer. I am tempted to say something about "maturity" of the presentation, but that is not exactly the point - products of this type do not change the sound in this direction, rather strengthening the advantages of the system than covering its disadvantages. Those, if there are any, will remain part of it. However, because the advantages gain some *weight**, subjectively they begin to matter more.

    The X Bulk Gold causes the music to "expand". I do not find another word that would accurately describe the effect I have heard. Please close your eyes and imagine the lace - a really pretty lace. Now put it down - still in your mind - on the table and cover it with glass. It's still the same lace, but it's different. The filter in question acts in the opposite direction, as if we removed the glass, and the lace returned to its natural, three dimensional state.

    The instruments are better differentiated with it, both in time, i.e. they have more distinct characteristics related to impact and pitch, to tempo, and so on, as well as to space, because their bodies are better defined. Interestingly, at first it seems that the sound stage is smaller, i.e. not so wide. It was particularly clear with with Ariel Ramirez's *Misa Criolla**. When José Carreras started to sing, with Bulk I could hear him better, deeper. But immediately after that entered a choir that without a filter in the system seemed spread really and with the filter was more focused around the vocal and placed further behind it.

    Only when listening to the next albums I realized that this “very wide choir” effect was actually an artifact. This was obviously a large interior of the church in the recording, but it was presented from a more natural perspective with the X Bulk Gold. Same happened with the electric piano (synthesizer?) in track no. 4 from the *3 City** album, which without the filter was closer and seemed bigger. But it does not take a great experience to realize that this apparently large volume of the instrument was caused by the fact that everything was a little more flat, like the lace behind the glass. It seemed more distinct, but only because the sound elements were less differentiated in time space, they were more blurred together. And that is probably the main advantage of the tested ground conditioner. From the recording, which in comparison to it sounded like a 2D one (although objectively it wasn't) it made 3D one without any processing, only by more palpable bodies of instruments, their nicer "here and now", even though the phantom images are positioned bit further away.

    Its tonal balance is set quite low, which is characteristic feature of this manufacturer's products. The performance is rather "sweet" than "distinct", "smooth" and not "contoured". In the first pair I wanted to use "vibrant” instead of “sweet, but quickly realized that it was not true. Although, after a short listening, one could say so. Because the sound is deep, actually dark, but in a high-end-dark way. That is, without emphasizing details, with showing off, with treble present only when needed.

    Ultimately, the X Bulk Gold is incredibly vibrant, which I confirmed playing the opening track from the *Go Right** album by Andrzej Kurylewicz Quintet - it was beautiful, sensual, but also with a great feeling. This can not be achieved without vibrancy. In comparison, the Acoustic Revive RPC-1 sounds brighter, higher. It delivers equally natural sound, but more detailed, more resolving, and thus with even more information about textures, changes of pace, dynamics. These two devices offer two equivalent interpretations of the same material, and it will be you who decides, which one suits you better. In terms of tonality, the Verictum filter would be much closer to another "conditioning" product, the Asura platform for power strips.


    The previously mentioned ground conditioners are well priced because the quality of changes they introduce to the sound is equivalent to the price progression. Nevertheless, the X Bulk Gold had the most common features with the twice as expensive product of Mr. Ken Ishiguro (RPC-1). The Polish ground filter created an equally addictive and natural performance, but based on different rules. It was darker, denser, with further placed phantom images surrounded by an incredibly natural space. This is a unique product that you can live without (see introduction). But should you really?

    Technical specification (according to manufacturer)

    Conductor: SC silver 4N with cryogenic treatment
    Length: 90 cm
    Plug: Furutech FI-E11Cu
    Dimensions: 145 x 140 x 100 mm
    Weight: 1.9 kg



    - Turntable: AVID HIFI Acutus SP [Custom Version]
    - Cartridges: Miyajima Laboratory KANSUI, review HERE | Miyajima Laboratory SHILABE, review HERE | Miyajima Laboratory ZERO (mono) | Denon DL-103SA, review HERE
    - Phono stage: RCM Audio Sensor Prelude IC, review HERE

    - Compact Disc Player: Ancient Audio AIR V-edition, review HERE

    - Line Preamplifier: Polaris III [Custom Version] + AC Regenerator, regular version review (in Polish) HERE
    - Power amplifier: Soulution 710
    - Integrated Amplifier: Leben CS300XS Custom Version, review HERE

    - Stand mount Loudspeakers: Harbeth M40.1 Domestic, review HERE
    - Stands for Harbeths: Acoustic Revive Custom Series Loudspeaker Stands
    - Real-Sound Processor: SPEC RSP-101/GL
    - Integrated Amplifier/Headphone amplifier: Leben CS300XS Custom Version, review HERE
    - Headphones: HIFIMAN HE-6, review HERE | HIFIMAN HE-500, review HERE | HIFIMAN HE-300, review HERE | Sennheiser HD800 | AKG K701, review (in Polish) HERE | Ultrasone PROLine 2500, Beyerdynamic DT-990 Pro, version 600 - reviews (in Polish): HERE, HERE, HERE
    - Headphone Stands: Klutz Design CanCans (x 3), review (in Polish) HERE
    - Headphone Cables: Entreq Konstantin 2010/Sennheiser HD800/HIFIMAN HE-500, review HERE

    - Portable Player: HIFIMAN HM-801
    - USB Cables: Acoustic Revive USB-1.0SP (1 m) | Acoustic Revive USB-5.0PL (5 m), review HERE
    - LAN Cables: Acoustic Revive LAN-1.0 PA (kable ) | RLI-1 (filtry), review HERE
    - Router: Liksys WAG320N
    - NAS: Synology DS410j/8 TB
    System I
    - Interconnects: Acrolink Mexcel 7N-DA6300, review HERE | preamplifier-power amplifier: Acrolink 8N-A2080III Evo, review HERE
    - Loudspeaker Cables: Tara Labs Omega Onyx, review (in Polish) HERE
    System II
    - Interconnects: Acoustic Revive RCA-1.0PA | XLR-1.0PA II
    - Loudspeaker Cables: Acoustic Revive SPC-PA

    System I
    - Power Cables: Acrolink Mexcel 7N-PC9300, all system, review HERE
    - Power Distributor: Acoustic Revive RTP-4eu Ultimate, review HERE
    - Power Line: power cable Oyaide Tunami Nigo (6m); wall sockets 3 x Furutech FT-SWS (R)
    System II
    - Power Cables: Harmonix X-DC350M2R Improved-Version, review (in Polish) HERE | Oyaide GPX-R (x 4 ), review HERE
    - Power Distributor: Oyaide MTS-4e, review HERE
    - Stolik: SolidBase IV Custom, read HERE/all system
    - Anti-vibration Platforms: Acoustic Revive RAF-48H, review HERE/digital sources | Pro Audio Bono [Custom Version]/headphone amplifier/integrated amplifier, review HERE | Acoustic Revive RST-38H/loudspeakers under review/stands for loudspeakers under review
    - Anti-vibration Feets: Franc Audio Accessories Ceramic Disc/ CD Player/Ayon Polaris II Power Supply /products under review, review HERE | Finite Elemente CeraPuc/ products under review, review HERE | Audio Replas OPT-30HG-SC/PL HR Quartz, review HERE
    - Anti-vibration accsories: Audio Replas CNS-7000SZ/power cable, review HERE
    - Quartz Isolators: Acoustic Revive RIQ-5010/CP-4

    - FM Radio: Tivoli Audio Model One