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Audio Replas

Manufacturer: AUDIO REPLAS Co., Ltd.
Price (in Poland):
• OPT-100: 193 900 JPY (4 pieces)
• OPT-30: 155 800 JPY (3 pieces)

Contact: tel.: 0778-24-542 |


Provided for test by


translation Ewa Muszczynko
images Wojciech Pacuła

No 217

June 1, 2021

AUDIO REPLAS is a Japanese audio company specializing in anti-vibration and power supply products. Its founder is Mr. RYUICHI IKADA, who is also its main constructor. The company has existed since 1994. This time we are testing its insulators made of specially crafted quartz.

UR FIRST CONTACT WITH THE AUDIO REPLAS COMPANY took place ten years ago. At that time, we looked at several products for vibration reduction and RFI noise elimination. Every self-respecting audio company has its own techniques to be used in these domains, so it is no different with Audio Replas.

Its anti-vibration products are based on precision-machined components made of quartz which you'll find in almost all of its insulators, as well as LP presses. A separate section is devoted to power supply products – both AC power strips and cables, as well as various types of passive filters. As before, this time we will take a look at both, along the way also taking a look at acoustic material designed to shape room acoustics.

To maintain transparency, the article has been divided into two parts. In the first one we look at a passive AC supply voltage filter called the CPC-43ACP, while in the latter, which you are reading now, at the feet/insulators OPT-30HG20SS HR/3P and OPT-100HG-FLAT-SS HR/4P.

In order to better understand both the company and its products, I asked Mr. RYUICHI IKADA for “a few simple words” – you will find the interview in the first part of the article HERE.


THE PRODUCT NAMES OF THE AUDIO REPLAS COMPANY are not "friendly". However, this is the case with many Japanese manufacturers, not an exception. Instead, they are logical. Their creators think about products in a technocratic, engineering way, not a descriptive one. And when you realize this, it becomes easier to understand what the given name is all about.

The OPT-30HG20SS HR3P & OPT-100HG-FLAT-SS HR4P belong to the group of products serving to reduce vibrations of equipment and speakers placed on them. They are made of pure quartz in a technology developed by the company owner, Mr. Ikada. As he said in the already quoted interview, he made his first attempts with conventional quartz stands, and those attempts failed him – he was not satisfied with the sound quality he obtained.

So he carried out a series of studies on its physical properties and, based on that, developed its type for use in audio, which he called HR Quartz Glass. In addition to the material itself, the finish is also important. Mr. Ikeda believes that in order for this type of insulators to fulfill their purpose, the surface on which the shelf and the product that is placed on it come into contact must be as flat as possible. So, he found a company that polishes insulators in a super-precise way down to – as we read in press materials – "the molecular level". This is exactly the same way top optical products are made in Japan. Thanks to this, as the head of Audio Replas says, sound harmonic distortion is ideally reduced.

This quartz has a Mohs hardness of 7, while crystal has a hardness of 5 and diamond – of 10. Due to the combination of these factors, the intrinsic resonances of the insulators, as measured, are far outside the useful band. The result is a proprietary version of HR (High Response)/SS (Super Surface) quartz insulators. And these abbreviations can be found in their names. Knowing this, it will be much easier for us to decipher them.

OPT-30HG20SS HR3P: 'OPT' means – this is my guess, not hard knowledge – that the insulator is transparent; matte insulators are also offered. '30' is its diameter ø, HG = High Grade, while '20' is its height. HR3P' is a cluster that means there are '3' 'pieces' (P = pieces) of High Response (HR) insulators in the box.

The symbol of the second group of insulators, OPT-100HG-FLAT-SS HR4P, should therefore be easier to read: these are four insulators made of high-end HR (High Response)/SS (Super Surface) quartz. In this case, however, number '100' does not give you their diameter ø, as this is not 100 but 50 mm; the insulators are flat and 5 mm high.


˻ THE WAY WE LISTENED OPT-30HG20SS HR3P feet are designed for mechanical decoupling of audio devices, replacing their feet and loudspeakers. OPT-100HG-FLAT-SS HR4P insulators are also used for this purpose, but in the case of electronic devices they are to be placed under the feet of the device.

Let me remind you that, for many years, I had been using a smaller version of the OPT-30HG20SS HR3P under the Harbeth M40.1 speaker stands and they were only replaced by the mechanically complex and expensive Pro Audio Bono feet. I also have several years of experience with flat quartz insulators – the RIQ-5010 and RIQ-5010W Acoustic Revive models. They are placed in my system, respectively, under the speakers and, instead of the original aluminum discs, on top of the Franc Audio Accessories anti-vibration feet, on which the Ayon Audio Spheris III preamplifier stands.

During the test, I tried out the feet under the Mytek Brooklyn Bridge file player. It stood on the top carbon shelf of the Finite Elemente Master Reference Pagode Edition Mk II rack on its own plastic feet. To weight it down a bit, I placed a Verictum X-Block passive EMI/RFI filter on top of it. In the package we get three feet, so one was on the front of the unit, and two were at the back.

I tested the stands with a Nordost QB8 MkII power strip. It stood on an Acoustic Revive RST-38H anti-vibration platform and powered only the Ayon Audio CD-35 HF Edition SACD player. In both cases, these were A/B/A comparisons, with known A and B. The music samples were 60 or 120 seconds in length.

Albums used in the test | a selection

⸜ STING, The Bridge, A&M Records | Cherrytree Records | Interscope Records/Tidal Master, FLAC MQA 24/48 (2021).
⸜ ART BLAKEY, Moanin’, Blue Note/Tidal Master, FLAC MQA Studio 24/192 (1958/?).
⸜ CHARLIE HADEN & PAT METHENY , Beyond The Missouri Sky (Short Stories), Verve Records/Tidal, FLAC 16/44,1 (1991/?).
⸜ HANIA RANI, Venice – Infinitely Avantgarde, XXIM Records/Tidal Master, FLAC MQA Studio 24/48 (2022).

Rock & Pops Hi-Res CD Sampler, Universal Music Japan UICY-40217/8, CD + MQA-CD (2018).
⸜ THE MODERN JAZZ QUARTET, Pyramid, Atlantic Records/Warner Music Japan WPCR-25125, „Atlantic 60th”, CD (1960/2006).
⸜ DIRE STRAITS, Brothers in Arms, Vertigo/Mobile Fidelity Labs UDSACD 2099, „Original Master Recording, Special Limited Edition | No. 1808”, SACD/CD (1985/2013).
⸜ PINK FLOYD, The Dark Side Of The Moon, Harvest SHVL 804, 1E 064 o 05249/Analogue Productions CAPP 81033 SA, SACD/CD (1973/2021).


IT IS AMAZING how products that shouldn't have such an impact on the sound change it IN SUCH A CLEAR WAY. We know from experience that they do, we know that they often have a big impact, and yet every time we are surprised by the profound effect they have on the reception of music. It was no different in the case of the two Audio Replas feet/insulators tested.

⸜ OPT-30HG20SS HR3P The feet placed under the Mytek file player ordered the sound. This is, I think, their main feature – minimizing uncertainty in the message. This makes it easier for our brain, for us, to absorb the sound, which thus seems more natural to us. The subsequent pieces I listened to were more interesting, denser in meaning and simply nicer with the feet under the device.

For a while I thought that the Audio Replas feet were modifying the bass by slightly dampening its excess. For when I played Waltz For Ruth from CHARLIE HADEN & PAT METHENY's Beyond The Missouri Sky (Short Stories), I heard Haden's powerful double bass and Metheny's baritone guitar set very low. The musicians, who are also the producers of the recording, showed it close to us in a warm way and intensified the low notes. It resulted in a tangible sound right in front of us. With the insulators under the Mytek player, there wasn't as much bass in the sound, and the low notes present were better controlled. And that's why I thought the OPT-30HG20SS HR3Ps were modifying the bass. It turned out it is different and that their effect on sound is much deeper.

When I heard the opening bars of the title track from ART BLAKEY'S Moanin’ album, it was clear that the insulators lowered the sound of both Lee Morgan's trumpet and Benny Golson's saxophone. It’s because they do something else than modify the timbre. They order sound and show it in a much more resolved way. Therefore, recordings have more of their own character, are better differentiated and thus more believable.

That's why I thought Haden's double bass had less bottom end and was more natural, that's also why the wind instruments from Blakey's CD had more low end and also seemed more real. It was as if the Audio Replas insulators triggered more color and emotion into the music. There was a change in tonal balance, but it changed from track to track instead of being constant.

For example, Sting from The Bridge album was better integrated with the band, and the bass slam was not so insistent. This is an album recorded with high compression, with not very good tangibility of instruments, but with Audio Replas insulators it had more grace and was prettier. Sting usually sings into a Shure SM58 dynamic microphone, and even if he sings into a different one, the sound is modified in a similar way. With the insulators, his vocal was smoother and deeper, as if some of the limitations of this simple microphone had been overcome.

⸜ OPT-100HG-FLAT-SS HR4P The insulators on which the Nordost AC power strip stood worked in a similar way. The sound was better differentiated and more resolved with them. Unlike with the feet under the Mytek player, however, the changes were not as profound. Yes, the difference was clear, but in this case it went in the direction of better sound opening and stronger accentuation of various details.

Interestingly, in all the recordings the timbre was slightly lower with them, as both the acoustic guitar in the track I’m Not in Love by 10CC and Rod Stewart's voice from Mandolin Wind were better articulated, but also better combined with the rest of the instruments. The guitar no longer "jumped" out of the right speaker but made musical sense and was better "anchored" in the mix. On the other hand, Stewart's vocal with the insulators was clearer, but, like the mentioned guitar, it "sat" nicer in the recording.

The differences in question introduce something more to sound than just timbre modifications. This also occurs, but is derivative. Compared to the Audio Replas insulators, the Acoustic Revive RIQ-5010W stands, also made from quartz, were more "present" in sound, giving it more of their own character. The effect of the Audio Replas insulators on sound, compared to the Acoustic Revive, reminded me of what the Ultimate HQCDs do, respectively, compared to regular HQCDs – we get higher resolution and more information with them.


BOTH GROUPS of Audio Replas QUARTZ INSULATORS change sound (modify signal) in a distinct way. The OPT-30HG20SS HR3P feet are more spectacular in performance and will work in any system – good or bad, expensive or cheap. They improve resolution by saturating music with harmonics and bringing order to the presentation.

The OPT-100HG-FLAT-SS HR4P insulators are different. They affect signal in a similar way but are more explicit in showing flaws of the system and recordings. So, I would use them in systems where everything is arranged, and which cost more rather than less. There, the insulators push sound in the right direction, i.e., the direction of credibility and transparency. They retain the saturation I heard with the OPT-30HG20SS HR3P, which makes them excellent tools.

After testing the insulators under my speakers, under which I've been using the Acoustic Revive RIQ-5010 discs, the smoky brown variety, for several years, I've decided that, ultimately, I'd like them there. I will also be using the OPT-30HG20SS HR3Ps for testing equipment, as they will bring out more of its "own" sound out of it. Both Audio Replas models are simply superb.


Reference system 2022

1) Loudspeakers: HARBETH M40.1 |REVIEW|
2) Line preamplifier: AYON AUDIO Spheris III Linestage |REVIEW|
3) Super Audio CD Player: AYON AUDIO CD-35 HF Edition No. 01/50 |REVIEW|
4) Stands (loudspeakers): ACOUSTIC REVIVE (custom) |ABOUT|
5) Power amplifier: SOULUTION 710
6) Loudspeaker filter: SPEC REAL-SOUND PROCESSOR RSP-AZ9EX (prototype) |REVIEW|
7) Hi-Fi rack: FINITE ELEMENTE Pagode Edition |ABOUT|


Analog interconnect SACD Player - Line preamplifier: SILTECH Triple Crown (1 m) |ABOUT|
Analog interconnect Line preamplifier - Power amplifier: ACOUSTIC REVIVE RCA-1.0 Absolute-FM (1 m) |REVIEW|
Speaker cable: SILTECH Triple Crown (2.5 m) |ABOUT|

AC Power

Power cable | Mains Power Distribution Block - SACD Player: SILTECH Triple Crown
Power (2 m) |ARTICLE|
Power cable | Mains Power Distribution Block - Line preamplifier - ACOUSTIC REVIVE
Power Reference Triple-C (2 m) |REVIEW|
Power cable | Mains Power Distribution Block - Power amplifier - ACROLINK Mexcel 7N-PC9500 |ARTICLE|
Power cable | Power Receptacle - Mains Power Distribution Block: ACROLINK Mexcel 7N-PC9500 (2 m) |ARTICLE|
Power Receptacle: Acoustic Revive RTP-4eu ULTIMATE |REVIEW|
Anti-vibration platform under Acoustic Revive RTP-4eu ULTIMATE: Asura QUALITY RECOVERY SYSTEM Level 1 |REVIEW|
Power Supply Conditioner: Acoustic Revive RPC-1 |REVIEW|
Power Supply Conditioner: Acoustic Revive RAS-14 Triple-C |REVIEW|
Passive filter EMI/RFI: VERICTUM Block |REVIEW|


Speaker stands: ACOUSTIC REVIVE (custom)
Hi-Fi rack: FINITE ELEMENTE Pagode Edition |ABOUT|
Anti-vibration platforms: ACOUSTIC REVIVE RAF-48H |ARTICLE|

  • HARMONIX TU-666M "BeauTone" MILLION MAESTRO 20th Anniversary Edition |REVIEW|


Phono preamplifier: Phono cartridges: Tonearm (12"): Reed 3P |REVIEW|

Clamp: PATHE WINGS Titanium PW-Ti 770 | Limited Edition

Record mats:


Headphone amplifier: AYON AUDIO HA-3 |REVIEW|

Headphones: Headphone Cables: Forza AudioWorks NOIR HYBRID HPC