Yukimu RCA and USB Noise Absorber

Introduction

The Yukimu PNA-RCA01 ("RCA Plug") and PNA-USB01 ("USB Plug") are plug-in noise absorbers designed to absorb high-frequency noise from your audio/video components. These products were designed by Mr. Masahiro Yamazaki, an experienced engineer who worked for Matsushita Electric Industrial, specialising in circuit design for the Technics Brand which is part of Matsushita. 

Carefully selected parts such as British LCR styrene capacitors and Amtrans non-magnetic carbon film resistors (AMRG 2W) are used. The hand-made circuit is hard-wired and soldered using lead-free silver solder.  

A resistor and capacitor circuit is used in conjunction with an electromagnetic wave absorption sheet and metal case of the product to absorb noise. Assuming an output resistance of 220 ohms, Yukimu claims that the RCA Plug attenuates noise at 22 MHz by 18db. R-C circuits are commonly used to reduce noise, so this isn't a snake-oil tweak and is well-grounded in science.

The RCA Plug utilises a brass shell, while the USB Plug uses a A6061 aluminum case.

Description

Both products come in a beautiful wood box, with a certificate confirming that the product was manufactured and evaluated by the named employee which just so happened to be Masahiro-san. 

Yukimu's website explains that the RCA Plug can be used on any RCA analog or digital socket (including output sockets).

In Use

Like any grounding product, some experimentation is required to get the most out of the Yukimu. On a Schitt Freya+ preamp, the effect of the RCA Plug on each socket varied in intensity. The intensity was highest on a spare input, while the output socket was slightly tamer.

Regardless of location, the effect was quite consistent. You get a tightening of the bass, and clearer and more extended high frequencies. While the midrange clarity and texture improved, there is an increase in "presence" that moves vocals forward in the soundstage. While expressiveness of singers improved, sibilance was also more noticeable.  

The preferred intensity will be a matter of taste. I found that the tonality of my system was too forward and bright when used on the input socket, and just right on the output socket. 

The effect of the USB Plug is similar, but I found that the increase in dynamics and bass heft to be more pronounced than the RCA Plug, making the USB Plug sound more balanced. Deployed on the front USB port of my Intel-NUC Roon ROCK server, there was an all-round increase in dynamics, clarity and focus. There was less alteration to the tone of my system and if I had to choose just one, my money would be on the USB Plug. 

The audiophile mind already predicted that using both products at the same time would result in an overly bright and forward presentation. Somehow, both products sounded quite good together, although the tone was still on the bright side of neutral. Who would have guessed?

Conclusion

This is an effective product that is meticulously made. The price tag is reasonable for the performance although some caution should be noted given the resultant shift in tonal balance. Judicious trial and error is required also to get best results -  Highly Recommended.

Yukimu products are available in Singapore from Audio Basic.

Yukimu PNA-RCA01 / PNA-USB01  - S$ 520 each (promotional price)

Audio Basic
1 Coleman Street
#02-12, The Adelphi 
Singapore 179803
http://audiobasic.blogspot.com

  

International Sound & Sight Exhibition 2022

International Sound & Sight Exhibition (ISSE) ran from the 2nd to 4th of December 2022 at Holiday Inn Singapore Orchard City Centre. This is the very first ISSE held since the COVID pandemic.

Here are the pictures taken and my commentary on the rooms. Apologies for missing out on some rooms due to time constraints. 

EAhibrid and Cornerstone Audio

This room was shared by three exhibitors, EAhibrid, Cornerstone Audio, and a Thai gentleman that was demonstrating his tweaks and footers. EAhibrid was showcasing their Pure DC B1 battery supply that uses 2170 lithium batteries that are also used in Tesla EVs. Mr. Paul Huang, founder of EAhibrid explained some of the technology used in the Pure DC B1. I happen to have one at home, so I will do a detailed review on that soon.

Cornerstone Audio is new to ISSE. For such a young company, they have an impressive list of brands under their belt, including Quadraspire (racks), QLN speakers, Sean Jacob power supplies and Lab 12. 

The very cute looking accessory is both a resonator and grounding device. Called "Meow", they are sold in both male and female version. The ears act as a waveguide and the tail unscrews to accept the grounding cable.  

Atlas Sound & Vision
  

Atlas had two systems on demo. The first system was a combination of NAD electronics and GoldenEar speakers. The limited edition NAD C 3050 LE was available for pre-order too. The classic looks were really attractive. This system surprised me with its big and dynamic sound. I was convinced that the big GoldenEar tower speakers were playing, but it turned out to be the diminutive BRX bookshelf speakers. I did a professional review on these, so I really should have seen it coming.

The Accuphase and KEF setup oozed refinement and control. This was even more surprising as the music was being streamed through a Bluesound Node wireless streamer which was connected to a DAC card in the Accuphase amplifier. Really nice sounding setup!

High End Research

High End Research assembled a relatively modest system this year (by their standards) with A Metronome CD player, Electrocompaniet preamp, Pass Labs power amp and Wilson Audio Alexa V speakers. 

Horizon Acoustics and Project Perfection

Horizon paired their electronics (Totaldac server and DAC, Modwright buffer, AGD pre and monobloc amplifier) with Project Perfection's Diptyque speakers. The sound was very comfortable, relaxing and resolving at the same time. 

The Modwright Analog Bridge is an especially interesting product. Offering a choice of both 6922 and 6SN7 tubes which are switchable on-the-fly, the Analog Bridge also uses a 5AR4 tube rectified power supply. This is the perfect candidate for adding tube warmth into a system. You could use it after a DAC with digital volume control, or a passive preamp.  

Project Perfection

Project Perfection used Audio Research Electronics with Apertura speakers. It baffles me how they got so much clean and deep bass from that modest-sized two way speaker!

Stardust Pictures Pte Ltd

All eyes and ears were on the Falcon LS3/5A gold badge speakers, and for good reason. Supremely musical and engaging, I saw two orders being placed while I was in the room. Stardust are also newly appointed distributors for Alexandria Audio from Bali. 

Simplicity Control - Magico and Luxman

Absolutely beautiful Luxman electronics paired with Magico speakers. 

Ong Radio

I've always had a soft spot for the soft blue meters from the big M. Ong Radio was playing some soft relaxing music when I was there, which was a perfect match for the hypnotic meters. 

Reference Audio

CH Precision and Melco electronics, with Gryphon speakers and amplifier. 

Simplicity Control - The "If you have to ask, you can't afford it" Room

At a wallet busting $ 1,081,925 this system is destined only for the extremely well-heeled. Once upon a time, this would have been considering an eye-watering price tag, but thanks to soaring property costs, this sum only covers about 70-80% of the cost of centrally located public housing in Singapore.

Consisting of Goebel speakers, EMMLabs digital equipment, Kronos/J Sikora/ DS Audio analog equipment, Pilium amplification and Albedo/Goebel cabling, I would describe the sound as tight and supremely controlled.

Sound Decisions

The Sound Decisions boys had a variety of stuff on display. When I was there, the Dutch & Dutch 8C speakers were in play. Supported by an able cast of an Innuous streamer, Merason DAC and Synergistic Research power conditioner, these speakers sounded wonderful. On the last day, room equalisation was employed. So if you heard them on the first and second day, you didn't hear them at their best. These had a tight, grippy and highly detailed sound. 

The Perraux and Amphion gear colourway was quite striking, and may just seal the deal if you are having problems with the Minister of Home Affairs. 

Sky Audio

The Divini Reference 8 speakers sounded good. The drivers look like they are from the Scanspeak Revelator series. Partnering electronics were from SPL. In consistent Sky Audio fashion, the setup was tuned to be musical and engaging. 

Yamaha Singapore

Having heard the NS-5000 speakers at previous ISSE, I can confirm that these are truly special speakers. The previous pairing with Pass Lab amplification was more to my liking though, but these are still worth further investigation.

Kojo Technology Crystal E Ground Box and Crystal EP Plug

Introduction

Kojo Seiko Co. Ltd is a medium-sized company located in Hirakawa City in Aomori, Japan. Established in 1990, they are involved in a variety of electronic-related businesses ranging from power supply design and manufacturing to audio accessories.

Description

The Crystal EP is a virtual earth product that improves the grounding of audio equipment. The device is a barrel-shaped plug with various connectors available :- RCA, 3.5mm mini plug, banana and spades. The barrel contains 100 cm2 of high-purity aluminum foil treated with a special etching process to create cavities that increase the surface area to 11,000 cm2. The rear of the Crystal EP plug unscrews to accept a grounding cable for connection to the optional Crystal E Ground Box. 

The Crystal E Ground Box is a compact metal ground box that houses an eight-layer plate structure that functions as a virtual ground. The plates comprise a combination of stainless steel, brass and copper plates. The plates are stacked, with a 0.5mm air gap between each plate. The box measures 80mm (W) x 35mm (H) and 111mm (D) and weighs 775 grams.

Picture taken from Kojo's website

There are two screw terminals at each end of the box. One terminal is used to connect the grounding cable to the component or Crystal EP plug, while the other end is used to daisy chain a second Crystal E Ground Box. Two ground cables of 1.2m length are thoughtfully provided in the package, one with spades on both ends, and the other with a spade and RCA plug.

You can use the Crystal EP plug alone, or connected to one or more Crystal E Ground boxes. Alternatively you could use the Crystal E Ground connected directly to the component in question. 

The Crystal EP Plug is made out of three pieces. The first piece is the termination plug and is interchangeable. The second piece is the main housing, and the last piece is the screw terminal that accepts the spade-terminated grounding wire that connects to the E Ground Box. This allows you to easily change the termination plug in case your needs change in the future, and also to stack the plugs if required. How you apply this product in your system is limited only by your imagination.

Sound Quality

Kojo is not my foray into grounding products, being a long-time user of Entreq ground boxes. Grounding accessories take a bit of experimentation to get right, with the results being very much system and component-dependent. Kojo products come in at a lower price-point compared to Entreq and are more compact, allowing you to deploy them in tight spaces.

The Crystal EP Plug increased focus and vocal texture, with more bass power. Dynamic contrast increased with instruments and vocals becoming more distinct. The effect was very noticeable with a 3.5mm EP Plug inserted into a Creative Soundblaster X4 DAC/headamp, with similar results pairing an RCA EP Plug with a Schitt Audio Freya+ preamp. Using twin RCA EP Plugs (on an unused input and output socket) increased the effect, but also sounded a bit too forceful and artificial for my taste. 

Linking the EP Plug to a Crystal E Ground Box increased the level of refinement across the board, and added a calm sereneness to the music. It also added midbass weight which balanced out the extra energy on the midrange and treble. This turned out to be my favourite combination in listening tests. 

As counter-intuitive as it sounds, do also try grounding the phono stage in your integrated amplifier (even if you don't play records). Attaching the Crystal E Ground Box to the ground lug of the Marantz 40N gave great sonic dividends, sorting out a vague and diffuse sound stage. 

I tried adding Crystal EP Plugs to the negative terminal of my speakers. While the effect was similar, I found it to be more subtle compared to tweaking the source equipment. As I only had a single Crystal E Ground Box on hand, I was not able to ground both plugs.

Conclusion

The Kojo Crystal EP Plug and Crystal E Ground Box earn an easy Best Buy award from me. Improve your system for a modest outlay! However, as with all grounding products, do try before you buy since tweaks of this nature are highly system-dependent. 

A big thank you goes out to Sky Audio Singapore, local distributor of Kojo products for providing the review samples. I personally purchased the EP Plug and Crystal E Ground Box.

Catch them too at International Sound & Sight Exhibition 2022. The show will be on 2-4 December at Holiday Inn Singapore Orchard City Centre, 11 Cavenagh Road, Singapore 229616.  

Kojo Technology

Crystal E Ground Box - S$ 450 per piece

Crystal EP Plug - S$ 225 per piece (promotional price)    

Sky Audio Singapore

28 Sin Ming Lane,

#05-137 Midview City

Singapore 573972

http://www.skyaudio.net