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Integrated Amplifier



Manufacturer: Onix Electronics Ltd
Price (in Poland): 10 500 zł

Brighton Sussex – England
tel.: +44 1273 906977

Country of origin: Great Britain/England

f a survey was sent out to audiophiles that asked what associations they had with components from ONIX, I'm sure that most would associate them with Densen, followed by classic brands such as NAD. Newer companies would include Carat and Advance Acoustic. Large gold-plated knobs and sleek black faceplate would point to Densen, while classic looks and overall elegance would suggest NAD. On the other hand, acrylic fascia would be surely reminiscent of Carat and AA. As I say, I'm fairly sure of that as I actually did ask a dozen of friends about their opinion of the RA-125B’s finish design. The above brands and associations appeared most often in their e-mails. It turns out that Onix products largely owe their extremely attractive looks to Francesco Pace, an Italian who used to be an Onix distributor in his own country. He was most happy with their sound and internal build yet not quite convinced with what he saw on the outside, and offered to help design their new look. The renewed product lineups went into production in 2008, and Francesco’s Pacetech became Onix representative for the whole of Europe.

Onix Electronics Ltd. England is a brand owned by the Chinese company Shanling, known for various products sold under its own name and this year celebrating its 25th anniversary. Onix’s fate is similar to what has happened with another respectable, old British brand – EKCO (Eric Kirkham Cole Limited, now owned by IAG Group). Founded in 1984 in Brighton, England, under the name Onix Audio by three friends, Tony Brady, Adam Worsfold and Craig Hill, it grew famous for its shoebox-size amplifiers. Their first design was the OA-20 integrated amplifier that drew attention with its high quality power supply – not at all so obvious back then. The company manufactured excellent amplifiers and an interesting AM/FM tuner but ran into financial problems in the late 1980s. In 1990 years its shares, wholly owned by then by Adam Worsfold, were transferred to Onix Electronics Ltd and a year later sold to his new partner, Michael O'Brien. However, that did not help to recover the market share. After changing the name to Kendal Electronics Ltd in 1997, the company was dissolved later in the same year and eventually closed down. Like with many other British brands, a helping hand came from a Chinese company. In 2002, Shanling bought the rights to the name and started manufacturing Onix components in its own factories in the Middle Kingdom. In 2008, Francesco Pace took the matter into his own hands, which was to the good of Onix. The components now look better than ever before. What’s important, their design solutions are reminiscent of the best years of audio – they’re the classic of classics.

It takes a glance at the RA-125B to see what I mean. Its thick acrylic front panel harmonizes perfectly with the golden knobs. There’s no excess or style-over-substance, quite often found in Chinese products. Instead, it exudes restrained elegance. You can also see that it's all cost. Lifting the amplifier only confirms our suspicions of its provenance – it is a dual-mono design, with two large power transformers and a solid casing. All that stuff weighs a lot. It is a good sign, though. The amplifier’s name does not refer to its maximum power output, which is 130 watts per channel at 8 ohms. That’s really massive. It gets even better when we see what happens with the load down to 4 ohms. The power output nearly doubles and the RA-125B is capable of delivering up to 250 watts per channel. In addition to the RCA inputs, including power amp direct, the unit also sports balanced inputs. Typically they are a kind of adornment and the input signal is immediately de-symmetrized. Here, it is different. The signal is first handled by the preamp in the balanced form and is de-symmetrized after that, before reaching the attenuator. I suggest it’s worth trying out both types of inputs, XLRs and RCAs.

Albums auditioned during this review

  • Black Sabbath, 13, Vertigo/Universal MusicLLC (Japan) UICN-1034/5, 2 x SHM-CD (2013).
  • Count Basie, Live at the Sands (before Frank), Reprise/Mobile Fidelity UDSACD 2113, “Special Limited Edition No. 197”, SACD/CD (1998/2013).
  • Depeche Mode, Enjoy The Music....04, Mute, XLCDBONG34, maxi-SP (2004).
  • Et Cetera, Et Cetera, Global Records/Long Hair LHC00071, CD (1971/2008).
  • Et Cetera, Knirsch, MPS Records/HGBS Musikproduktion UG HGBS 20013 CD, (1972/2013).
  • Frank Sinatra, Sinatra at the Sands, Reprise/Sinatra Society of Japan/Universal Music Japan UICY-94366, SHM-CD (1966/2009).
  • Mel Tormé, The legend of Mel Tormé, Going for a Song GFS360, CD (?).
  • Nat “King” Cole, Welcome to the Club, Columbia/Audio Fidelity AFZ 153, SACD/CD (1959/2013).
  • Ornette Coleman, The Shape of Jazz to Come, Atlantic Records/ORG Music ORGM-1081, SACD/CD (1959/2013).
  • Pat Metheny, What’s It All About, Nonesuch Records/Warner Music Japan WPCR-14176, CD (2011);
  • Siekiera, ”Nowa Aleksandria”, Tonpress/MTJ cd 90241, 2 x CD (1986/2012).
  • Wolfgang Dauner Quintet, The Oimels, MPS/Long Hair LHC59, CD (1969/2008).
Japanese editions of CDs and SACDs are available from

I know a number of amps that in the output stage employed the same, now rarely seen, power transistors that we have in the RA-125B (see the Design section below). The powerful Sankens used to fire the imagination, promising high power output at low distortion levels. And they usually did not disappoint, or at least the design engineers did not disappoint as it was their skills and the type of application that the end result depended on. As far as I remember, all those amps, including the Audiolab power amp I recently auditioned, had several things in common. The most important was their absolute control over the sonic material. It had to do with something that usually escapes our attention but is often noticed when we hear music performed live. If we were to audition the amplifiers from the basic price range, say up to $3,000, paying special attention to that, most of them would turn out to have a rounded attack and subpar timing control. This leads to quivering that is often masked by a pretty, rich tonality and well-presented depth – both of the sound and of the soundstage. Onix amplifiers, however, but also those from Naim, show what we lose by that – dynamics, freshness and immediacy. Proper attack transients combined with a clean sound will get us an amplifier that is capable of conveying inner sonic relationships not only by means of its high resolution but above all by its perfect timing of sounds. The Onix belongs to such a group of amplifiers.

The characteristics I have just described are usually combined with what the audio press refers to as PRaT, which is an acronym for Pace, Rhythm and Timing. To tell the truth, I have never been particularly sensitive to this sonic aspect, as it has been clear to me that timing is something absolutely essential. I may not have given PRaT my special attention for another reason: in their best attempt to convey this aspect, the designers too often forgot about tonality, space and atmosphere. The end result was a sonic caricature, with contoured sound where everything may have had proper timing, but not necessarily made sense.
If, however, as in the case of Onix, there is no major push for that and if there is some ease-up for the sake of other sonic components that contribute to music presentation, we get the sound that is so interesting and so different from the audiophile market average that many audio enthusiasts and music lovers will be able to finish their quest and, with a sigh of relief, pull out their credit cards.
After all, the truth is that a large number of pretty cool and pleasing to the ear amps with ultra-lush sound are plain boring. If that’s what you like, if you mostly listen to Diana Krall and the likes, and smooth jazz is your joy, then such soft, warm sound will be absolutely spot-on. If, however, you need some madness, power, rhythm and punch, without forgetting the basic precautions, you just have to give the RA-125B a listen. It can offer things that you won’t find in “nice” sounding amps.

The amplifier under review can perfectly feel the track’s pulse. With the almost trance-like rhythms on Depeche Mode’s remixes we get one of the best, if not the best for the money, imaging of impact, dynamics and speed. Without any hardening of attack. The kick drum, whether synthetic like with Depeche Mode, or real as on Black Sabbath’s 13, is presented as if we listened to it here and now. In a similar manner, that is, as reproducing the “live” sound at home is – for many reasons – impossible. It is very well complemented by the amp’s overall tonality. It is not particularly warm, although the last thing I would call it is “dry” or “sharp”. There is plenty of treble, but not more than needed, and the upper midrange lights up the whole, without any unpleasant side effects. The first album I auditioned, Count Basie’s Live at the Sands (before Frank) just recently re-mastered by Mobile Fidelity, sounded deep and captivating. A large big band requires a high power amplifier if, of course at least for a moment, we want it to feel like a real concert. Unlike milder amps, the Onix does not “make up” the sound nor adapt it so clearly to a “home diet”. It played the material with panache, speed and power. And very differently than Sinatra’s own concert released by the Sinatra Society of Japan, which took place immediately after the events on the Basie’s album (CB’s band accompanied Sinatra). The Japanese disc sounds slightly dryer and more distant, although the material was recorded on the same evening, by the very same people. The differences in the remaster are shown immediately and easily be able to identify the two elements that this change is consisted of: lower density and lower resolution of the Japanese disc.

Differentiation is one of the amp’s strong points. Apparently, a combination of a fast slew rate, proper phase relations and good resolution resulted in a detailed sound that is open and has a “breath”, without glaring exaggeration. It was only with really bright material, such as Depeche Mode’s Something To Do. Black Strobe Remix , that once the vocals came in the upper midrange was somewhat emphasized. Not enough to make me skip the track but enough to just turn it down.
And there was plenty of room for turning it down as the Onix provokes to play it out loud. Its clean, fast sound is not only speed and clarity for their own sake, but also the lack of annoying quivering. Cleanliness also means the lack of grain between the instruments, and their easy sustain. We put on Black Sabbath and a moment later try to make out the shouts of the neighbor who somehow managed to get through to us. We sense intuitively that just one more click, another 1/15th rotation of the knob and we will get even deeper into the track, we will be even more “there”. There is, however, a limit to the amount of such loud information when it begins to irritate. We will easily recognize it when we have the desire to swap the disc. Turn down the volume and everything will be back to normal.


I think I’ve said everything there is to know. Speed, clarity and ease in driving the speakers. If you like to play it loud, it would be worth thinking about somewhat warmer speakers, such as Castle or Spendor. If you rather prefer an open and fast sound, I would look elsewhere. I cannot think of any speakers that the amplifier would sound bright or sharp with, as the cymbals have proper weight and sonority and no buzzing tarnish. If you hear any of that, it means that the speakers are the ones to blame, not the amplifier. The only thing you need to verify is a slightly stronger mid-bass that might be just too strong in your listening room. The soundstage is not deeper than with other components from that price range, and may even may seem shallower. Actually, a large number of “warm” amps only simulate that depth due to their better vividness. The Onix shows it just as it is. What comes out great is events across the soundstage and in counter-phase. They seem natural and immediate, just as the saxophones on Ornette Coleman’s album The Shape of Jazz to Come, which emerge suddenly and unexpectedly from nothingness only to be firmly and “permanently” located on both sides of the soundstage.
It is worth trying out the XLR input, as it offers a slightly deeper and more velvety sound. Not by much, but it’s still worth it. If you use headphones, you will be pleasantly surprised with the sound quality from the headphone output. With the Sennheiser HD800 I received an almost perfect sonic facsimile of the Onix with the Harbeth M40.1.

It is a really solid amplifier with very traditional looks, design and sound. It does not pretend anything nor does it deceive. It belongs in the same group as Naim components and that – for me – is saying a lot.

While testing audio components, one of the first decisions that must be made by the person responsible for it is whether to test the component sauté or accompanied by audio accessories. What the former has going for it is that we listen to the given product only and we do it the same way as the majority of music lovers do, immediately after purchasing it. In my reviews I introduced another principle – I try to “equip” the product with everything that is best for it, assuming that this way I will hear what it is really capable of, without filtering it through imperfect accessories. In the case of amplifiers it means providing good power, hence I auditioned the Onix powered via the Harmonix X-DC350M2R-Improved Version power cord. Other accompanying cables are also important. Interconnects – both RCA and XLR – as well as speaker cables were from Acoustic Revive: the RCA-1.0PA/XLR-1.0PA II and the SPC-PA. I also used the Tellurium Q Ultra Black speaker cables and it was my preferred combination.

I also care about what the reviewed components sits on. In my experience, confirmed by multiple auditions at the Krakow Sonic Society, that is almost as important as power supply. That’s why I try to place the components on the best possible anti-vibration platform and additionally use isolation feet. Over the past few months, I have been using two types of platforms – the Acoustic Revive RAF-48H air-floating board and the Harmonic Resolution Systems M3X-1921 RD isolation base. Isolation feet were the Ceramic Disc Classic from Franc Audio Accessories – the same ones I use under my CD player and preamplifier, retrofitted with the Acoustic Revive RIQ-5010 quartz insulators.
This time I decided to try a different setup which turned out to be at least equally good. It comprised the Acoustic Revive RST-38H quartz under board, on which I put four small Hickory cubes that are made by Acoustic Revive under the name HQ-4. An additional benefit, apart from the sonic improvement, was that the component looked great in such arrangement and was not raised high above the platform, which is inevitable with the Ceramic Disc Classic.

All that apart, the test had the character of a comparison audition. The reference point was my reference system and two all-in-one systems: the Naim UnitiQute2 and the Block CVR100+. Music samples were 2 minutes long; whole albums were also auditioned.

Speaker cables

When I first saw the Tellurium Q, I could not help but recall the look of cables from two other British companies – Linn and Naim. The shared many common features but the most important was that speaker cables from both companies had the form of so-called “eights” or copper braid separated by a flat ribbon. The cables looked almost the same as the – now long obsolete – 300 ohm antenna cables. They were just bigger. After reading the company’s history I knew that my intuition was right.
The history of Tellurium Q begins – so states the company literature – at a lunch in a recording studio, where two gentlemen met. They were Geoff Merrigan and Colin Wonfor, both directors, who began to talk and immediately found a common language: technology. Colin had an engineering background and specialized in analog equipment designs and high-frequency power supplies. He’d worked for companies that had contracts with the military and NASA, but also – as a consultant – for Naim. As we read further, at one point during the meeting Colin said that the main problem in getting high-quality sound was the cables. Geoff and his friend, the studio owner, got angry at that, as is often the case with people from the world of pro audio. An hour later, Colin had a ready material, in which he theoretically proved that he was right. And so was born Tellurium Q, which was tasked with putting Colin’s equations into practice. Both directors invested a lot of money in research and development, which resulted in the birth of the Tellurium Black.

It just so happens that the Polish distributor of Tellurium Q is the same company that also sells Onix products in Poland. It is no wonder that Onix components are usually showcased with Tellurium Q cables. To know what’s going on and at the same time to have a look at those new for me cables, I asked for sending for this review the RA-125 with the Ultra Black speaker cables, representing the top line from the manufacturer. Which does not mean expensive. The Ultra Black is a flat, wide strip with braided copper wire on both edges. Its major design objective was the lowest possible signal phase changes.
The British cables sound different than the Japanese Acoustic Revive, to which I compared them. They have darker tonality, show slightly more body and are a little less resolving. Their vividness, however, resulted in the Onix amplifier, and presumably also amps from Naim, Linn and the like (not just solid state as I would also try them with the LAR AI-30T II), sounding better than with the Acoustic Revive. What I got was a slightly warmer, deeper sound, still very fast but more velvety, which just turned out good for the amp. I think that sacrificing some detailness for it is perfectly justified. Sometimes “better” is no better at all and a compromise is more appropriate. In the case of Tellurium Q it is not painful but rather liberating. Highly recommended!

Price: 7790 zł/3 meters

The most important part of the RA-125B external design is a thick, black acrylic plate with contrasting gold-plated components – the volume and input selector knobs and the mechanical power switch. All lettering seems to be embedded under the top layer, which looks very attractive. The currently selected input is indicated with blue LEDs (I would prefer red). The rear panel is typical for this type of equipment, and a very similar arrangement repeats in products from Advance Acoustic, Xindak, Carat and many, many others. Some elements here are, however, evidently customized, or designed for that particular brand, which confirms high device status. That usually does not come cheap. To give an example, the solid gold plated speaker terminals that are used by half of the world here are marked “Onix England”. The CD input is not on regular RCAs soldered to the board, but on great-looking Super RCA connectors from American CMC, screwed into the rear panel. This is one of the five line inputs, four of them RCA and one XLR. One of the RCA inputs is a tape monitor loop and there is also power amp direct-in, which can be used to integrate the AR-125B with home entertainment systems. What deserves praise is a full 3-pin IEC socket that conforms to all necessary safety specifications. Below it, instead of a typical dull label there is a cute plate, indicating mains voltage and frequency.

The amplifier interior surprised me with its conservative but thorough approach to the components, circuit solutions and the amplifier design concept. All electronic circuits are mounted on a single large board. The only exception is a small microprocessor-based system protection board. Power transformers are not mounted to the board but to a stiffening steel plate. These are two large 300W toroids. The Onix is a dual mono unit with the electronics mounted on a single common board.
The active source is selected by Japanese relays from Takamisawa. The signal from the XLR inputs – another small board I forgot to mention – is sent to the main board to be processed in a balanced form by the preamplifier. That is why the XLR input parameters are slightly different from the RCA. Originally the board has space for another pair of solder-on RCAs – here they are replaced by quality Super CMC RCA connectors. The signal is then amplified in Burr Brown op-amps and via fairly long shielded cable travels to a classic Alps potentiometer on the front panel. It returns over identical cable to the power amplifier section built entirely on transistors. The current gain section is based on what is now increasingly rare but used to work in the most interesting amplifier designs: powerful pairs of Sanken 2SA1295+2 SC3264, mounted to separate heat sinks. The latter are rather small considering the amplifier’s rated power output, which means that the unit works fully in class AB. Quality passive components abound throughout. These include precision metal film resistors, Wima polypropylene capacitors, Elna electrolytics and large Super Gold filtering capacitors in the power supply. Both channel rectifiers are based on MUR8100 high-speed Schottky diodes to minimize switching noise. There is really no expense spared. The power amp input sports rare and expensive capacitors that seem to couple it with the preamplifier. Great job.

The remote control seemed to me familiar at first sight. As a matter of fact, it looks like remotes available with the previous generation of components from Austrian Ayon. The XRC-1 remote is compatible with all Onix products. The current component is selected with a small switch.

Specification (according to the manufacturer)

Power output:
2 x 130 Watts RMS (8 Ω) | 2 x 250 W RMS (4 Ω)
Dimensions (W x D x H): 430 x 401 x 119 mm
Weight: 14 kg
Power Consumption: 350 W

RCA inputs
Frequency Response: 10 Hz - 30 kHz (± 0.5 dB)
Input Sensitivity: 285 mV/47 k
Signal / Noise Ratio (SNR):> 104 dB (A-weighted, A)
Channel Selectivity:> 50 dB
THD: 0.003% (3/8 Ω)

XLR input
Frequency Response: 8 Hz - 35 kHz (± 0.5 dB)
Input Sensitivity: 485 mV/47 k
Signal / Noise Ratio (SNR):> 110 dB (A-weighted, A)
Channel Selectivity:> 60 dB
THD: 0.003% (3/8 Ω)

Distribution in Poland


Skype: hifielements


- 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
- Multiformat Player: Cambridge Audio Azur 752BD
- 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
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: fuse – 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
- 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
- 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