December 2012

RCM Audio TheRIAA Balanced Dual Mono Phono Preamplifier
A very special phonostage that virtually defines the word beautiful.
Review By Wojciech Pacuła

  I have had many a phono preamp go through my audio system – some were better, some worse, and some were pretty shit. Oh dear, I do not mean to sound sexist, like saying, "I had many women..." So let us start again: in my life I have used many phono preamps. No, that doesn’t sound much better either – as if I had the same thing on my mind. I’ll try the last time: I know (yeah, that sounds much better!) many phono preamps, probably over a hundred-plus. I know many of them well or very well. Three of them have been closest to what I mean by high-end: the Manley Steelhead, the RIAA preamp section in the Convergent Audio Technology SL1 Legend, and the RCM Audio Sensor Prelude IC. Of the three, I liked the last one the best. It is small, inconspicuous, ridiculously cheap (I know, manufacturers do not like to have their products or even their brand associated with the word "cheap" – but here it really hits the nail on the head) and comes from a tiny, two-people manufacturer RCM Audio in the city of Katowice, Poland. Both Manley and CAT were fantastic in their own way and without thinking twice I could share my life with them, who knows, maybe even "till death do us part." But if I were to pick one product that would make life fun and interesting – definitely not boring! – and surprising, it would be the RCM Audio preamp.

Over the past – I think about five – years I have been often met with confused stares, questions and even objections hurled at this small aluminum box. Why that one? Why so cheap? Why so ugly? Why from such an unknown company while I could have whatever comes to mind (which actually is true). I have had one short answer to all these questions: because it’s a device that proved great with all turntables and every single cartridge I have ever tested. Both with the 100,000 EUR Transrotor Argos and the astronomically expensive Air Tight PC-1 Supreme cartridge; equally well with the most expensive cartridges from Dynavector and Miyajima Labs and with the top turntables from SME or AVID. On the other hand, I have had the cheapest preamplifiers from Pro-Ject, basic cartridges from Audio Technology, Denon and Ortofon, and the Polish phono preamp was able to do justice to all, without any gimmicks, and to bring out the very best in them. This is the only phono stage with what I had to do that was so "stable" the. It’s the only phono stage I have ever reviewed that is so "stable" and so consistent, no matter what I’d hooked it up with.

And, from all I know, I’m not alone in that. John Bamford who reviewed the preamp for the November 2009 issue of "Hi-Fi News" was delighted with it and bought it as his reference device. And, from all I know, there are more of us, journalists and owners of very expensive turntable-based systems, who think similarly. It’s just that hardly anyone admits it. Why? Here’s my answer: because the Sensor Prelude IC is cheap and ugly, and because it comes from a country that only few people can locate on the map (not to mention the city...). It is also because you cannot comfortably select cartridge load. Now all this is about to change – ladies and gentlemen, please meet the THERIAA.

The THERIAA is a completely new design from RCM Audio and Roger Adamek, the company’s owner. In Poland, Roger (I will not pretend we don’t know each other) has been primarily known for his passion for analog. His distribution company RCM SC, out of which grew the RCM Audio, had been for many years one of the few places where you could listen to and buy turntables, cartridges, etc., despite the fact that almost everyone wrote analog off. Roger and his team are probably the best experts in Poland when it comes to analog. In his home audio system, the RCM Audio owner has had for years the 30A and, since some time, the 30/12 turntable from SME that he is a distributor for in Poland, with a top Dynavector cartridge. For years, he hooked up his turntables with the Sensor phono stage, just like me, unable to find a good reason to replace it with something more sophisticated. But something had to tip the scales and the new design, which had been in the making for a few years, was brought forward and realized in the form of the THERIAA.

From what I know, the preamp was designed by a different team than that responsible for the Sensor, however, both the turntable (SME 30 and 30/12) and the cartridge (top Dynavector), being Roger’s reference, and Roger himself as the ultimate "reference point", remained unchanged. The new device’s looks as well as its price are a completely different story than the first RCM Audio preamp.

It is a solid state dual-mono design, with a separate power supply. The power supply is symmetrical and the coupling with the main unit is via power cable terminated with very nice Amphenol plugs. The power supply has three filtration stages, with no less than 125,600 µF per channel. It employs capacitors from Elna, Panasonic (silver series), Nichicon Fine Gold and Wima, all carefully selected through listening tests.

The RIAA equalization circuit is fully passive. All passive components are hand-selected, individually for each single unit. The preamplifier has the total gain of 76 dB and boasts RIAA precision of +/- 0.1 dB (20 Hz to 20 kHz). Input mode is selectable: balanced or un-balanced. Nominal output level is 2 V (9 V maximum). Input capacitance is 100 pF. Gain can be adjusted in 8 steps (from 0.2 to 5 mV) and input impedance in 7 steps (from 20 Ohms to 47 kOhms).

When it comes to price – €9800 (incl. VAT) – its design and finish, we are in the world’s first league. The enclosure is made of 10 mm and 5 mm black anodized aluminum plates. The feet are made of stainless steel mounted to the device in a flexible manner.

The preamp is equipped with the following indicators:

·         Error (I assume red; never came up), indicating DC current on input

·         Overload (I assume red; never came up), indicating input overload

·         Wait (orange), on during system testing

·         Power (green), indicating power-on; separate for the left and the right channel.

Looking at the THERIAA and into its interior, let’s quickly go through some of the objections that (I think) the audience had when they saw the Sensor. The price and appearance of the new preamp is, as I said, the absolute top. OK, it still seems to be a bargain because it doesn’t even come close price-wise to products from Boulder, Kondo or even Zanden. But, I must admit, it is fairly expensive… The manufacturer is still tiny and unknown although a lot more people now know it and know where to find Poland. What remained unchanged is the not quite user friendly cartridge load selection, at least compared to the Manley (knobs on the front panel) or e.g. the Array Obsidian PH-2 phono preamp where all cartridge load settings selectable with the remote control. Array is a manufacturer owned by two Dutchmen, Chris van Liempde and Willem van der Brug that once manufactured electronics for Van den Hul.

Design
But let’s begin with the unit’s design. The THERIAA is a solid state IC based phono preamplifier with RIAA correction. Although Roger Adamek is a "tube" person through and through, when it comes to phono preamps he says "no" to tube designs for now. His latest preamplifier is a collaborative effort of RCM Audio and Mr. Adam Kubec, known in Poland for running Kustagon Labs. Mr. Kubec developed a preliminary design that was then modified by Roger, upon listening to an endless stream of consecutive versions employing a variety of ICs, capacitors, etc.

The main unit is housed in a very solid enclosure made of 5 mm and 10 mm aluminum plates. The housing is manufactured in Germany by Fischer Manufacturing to RCM specifications. The finish is professional. Maybe slightly old-fashioned, alluded to e.g. by the mounting of LED on the power supply, but nevertheless really classy. The power supply chassis is more modest, but it is still OK. The top cover of the main unit is lined with vibration damping material. Strips of the same material are also on all other panels.

The front panel features eight LEDs in two rows of four, indicating device’s current status. Two rows since it is a true dual-mono design and can be viewed as two separate devices in one box.

That channel separation is also visible on the rear panel – the inputs, gold-plated RCAs, and the RCA and XLR outputs are far apart. That shows how far from each other are each channel PCBs. At one side is a very solid Amphenol bayonet power connector with gold-plated pins to connect a 2 m long DC power cord from the separate power supply box housing transformers and rectifiers. There is also a grounding terminal (with which all manufacturers seem to have problems – it’s either too small or too big, or something else is not quite right – I honestly don’t know a single well-designed grounding terminal…). And there are DIP switches to select input impedance, gain, and balanced or unbalanced input mode. In my case the former always proved better.

The interior will please the eye of anyone who knows the stuff. It is divided into three chambers – one each for the left and right channels, and a small housing for the power cord. The channels are separated by a 10 mm aluminum plate and one channel is separated from the power cord by an aluminum angle bar.

Each channel is built on two PCBs – one contains voltage regulators and the other is gain stage with RIAA correction. The gain stage is based on ICs, five per channel. At the input we see THAT Corporation 1510, an ultra-low noise wide bandwidth amplifier with high gain. Interestingly, one of its intended applications in addition to audio systems is sonar... Next is a National Semiconductor chip I couldn’t read as it’s covered by a resistor. It’s a part of a protection circuit against DC in the input. The PCB also houses a large TL074 STMicroelectronics chip with JFET input, working as system logic (LEDs, relays, etc.) – it is not in the signal path.

The second gain stage is based on Burr Brown OPA2134 and THAT 1610. The circuit as a whole seems to be balanced despite the fact that there are no XLR inputs. Passive components are excellent – they are precise metallized resistors and Wima and EVOX (lots of EVOXs) polypropylene capacitors as well as Nichicon Fine Gold and Panasonic electrolytic capacitors. DIP switches are from Omron. The entire unit is assembled very neatly, there is nothing to hide.

The second PCB in each channel, located closer to the front panel, is a complex power supply. It contains 18 (per channel) electrolytic capacitors for voltage filtering and three additional polypropylene capacitors. Among them we see two (per channel) Linear Technology LT3080 voltage regulators on heat sinks. Clean, professional design. But what else to expect – Adam Kubec is a high-class specialist, owner of a company designing automation systems for large plants such as coal mines. There can be no mistake, makeshift or bungle. That is coupled with the audiophile experience of Roger Adamek for whom the point of reference are products from SME, Dynavectora, CEC, and Vitus that he’s been distributor for years.

Finally, the power supply. It is about half the size of the main unit and has a slightly different chassis. Front and back are made of aluminum plates, while top, bottom and the sides form a closed profile into which slides the power supply PCB. Despite being simpler it is still a very solid, rigid design. Only the feet are rather mundane – rubber hemispheres glued to the bottom of the chassis.

The front panel sports a LED indicating power-on, the rear features an IEC mains socket with a fuse and a large, mechanical power switch. PSU is built on one big PCB. In the input, looking from the front panel (lined with a dampening mat) we have a large mains filter and two transformers, one for each channel. Behind them we see bridge rectifiers on heat sinks and quite a lot filtering capacitors – six per channel. Both channels of the power supply are separated from each other with a thick aluminum plate that works as shielding. The rear sports DC power cord with four pairs of twisted copper wires and an additional ground wire.

It is a very fine piece of manufacturing, showing extremely high theoretical and material design, the result of years of experience in distribution and manufacturing, of being an audiophile and music lover, a perfectionist.

Sound
That review was totally different than 99.99% of my reviews. Normally, while listening to music I try to make a synthesis of what I hear; I compare and learn as if I were a potential customer looking for an audio device for himself. I swap records, change components surrounding the reviewed device; I search and investigate.

With the THERIAA I did all that but it was subordinate, derivative - something that would only assure me of the primary trait of that listening test. That trait was contemplation. No, I don’t use a rhetorical figure to state the quality of the product, to "imprint" it in the reader’s mind. It is obviously one of the tools of the journalist, of doing his job which after all is to share some TRUTH about the product. This time, it was a total contemplation.

Let me start with a small confession: I am absolutely, completely satisfied with the RCM Sensor. I know it well and it’s been a great reference point for everything I have listened to in my life. It is like a solid "border post". Nevertheless, from time to time I’d come across a device that was better in some aspects and once or twice (Manley, CAT, Vitus – OK then, three times...) I heard or reviewed products that objectively speaking were better than the Sensor. Period.

However, this time I was listening to a product that was not just better. That much was "evidently evident", so to speak. Right from the first album, listened to late at night on headphones, just after the RCM arrived at my house – the 1987 "Making Music" by ZakirHussain [ECM 1349] – I was aware I was listening to something from another story altogether. Describing treble, bass or such like would be pointless since at this price level such details simply do not apply. Here we listen to something else and something else we hear. I will therefore use a few key words that will make it for a somewhat short review but perhaps the densest, most rich in meaning I have ever written.

Purity is the first characteristic we notice. It seemed to me that the Manley Steelhead sounds pure and that the Sensor has ultra-pure sound. That’s not true. Almost all phono preamps I know, perhaps except the Vitus and the CAT, have more "cluttered" sound. What I mean by that is not hum, interference or something equally banal. The point is that when we have a dense recording, when we listen to a poorly produced album, the best preamps such as the THERIAA arrange and order all sonic aspects so that we can make sense of what’s going on and easily reach behind the layer of record production flaws, intentional or accidental deviations from neutrality. It was true with overly bright and somewhat chaotically produced recordings, e.g. the compilation "Stars and Topsoil" by Cocteau Twins (4AD, CAD 2K19) released on white vinyl, but also with the recently released anniversary version of the album "So" by Peter Gabriel (from the "25th Anniversary Deluxe Edition Box Set", [Realworld, PGBOX2]. Such recordings, and we can throw in here the failed EMI reissues of Sinatra and Queen (digital remasters), sound dry and flat. Latest vinyl releases from Munich-based ECM sound even worse, as if ECM experience somehow vanished.

All of these albums sound dry and ugly even on the Sensor. The CAT, owing to its phenomenal saturation, toned down some sharp coloration in the 2-4 kHz range but in general still sounded weak. The THERIAA went deeper. It didn’t muddle anything up, didn’t pretend that there was no problem, but by ordering everything and clearing it of "debris" it reached deeper into music and showed it as a one-time event, not a collection of separate elements. And even though its treble is better and stronger than all the above cited devices, it was never loud as it happened from time to time with its competitors.

Another key word is coherence. It’s a characteristic I was able to experience a few times in my life, e.g. with the top turntables from AVID and SME, with the Transrotor Argos, and with the Air Tight PC-1 Supreme cartridge. Here I had the same thing. It is manifested in the interaction of all sound components and building something more, something beyond "sounds". We don’t feel the need to analyze what we hear but instead simply evaluate it, quite instinctively and naturally. In Hi-Fi analysis almost always precedes evaluation – we ask "what" and "why", "how" and "where". Sometimes also "compared to what". With the preamp from Katowice there is no such need. Everything is in place – there is very well developed treble and deep, meaty bass, there is saturated midrange and great color. Therefore, we accept it as something normal and given. We stop for deeper elements – why such an instrument, how are particular layers in relation to each other, what was the atmosphere at the time of recording. It is audible not only on purist reference recordings from Analogue Productions, Speakers Corner or ORG, but also on records cut from digital masters.

Of course – the closer to analog master tape and the higher the rotational speed (45 rpm), the closer and more natural presentation. Yet, the THERIAA doesn’t disqualify inferior pressings and poorly produced album. It shows the "what" and "how" but immediately reaches deeper, drawing us into music. As I say, I never liked Peter Gabriel’s "So" production-wise and I think that there’s "something" that causes subconscious fatigue, irritation, regardless of pressing, release and format (incidentally, the worst is hybrid SACD CD remaster...). The reviewed preamp somehow broke through this layer. Although it shows more detail by being more selective than any other phono stage I am aware of, its treble seems to be calmer than the Vitus or Manley preamps. Only the CAT did something similar but it was through rounding and warming of sound.

And finally the category that is most difficult to undergo falsification which is – in my opinion – the basis for any scientific study (and that is what audio listening tests are, as examination by inspection). I am talking about beauty. The definition of beauty depends on each one of us; its understanding changed both historically and geographically, etc. However, I think we can find common ground for all these views. It is easier in our case, since we live in the same time and – ultimately – the same place. And we listen to similar music.

And music through the THERIAA is simply more beautiful than with other preamps. Even though I really appreciate the devices from Manley, Vitus, CAT, but also from Boulder, Ypsylon, Zanden, Kondo, etc., they all bring with them a "hump" of added meanings, brand, promotion, advertising, some sort of "halo" that makes them no longer just "relays" because they affect the way we "perceive" music conveyed by them. The Polish preamp seems to me absolutely unpretentious against that background – from its appearance to its approach to the subject. It sounds equally beautiful as the best phono preamps I know; it is outstanding at differentiating recordings but does it somewhat casually, without pomposity.

Conclusion
Roger Adamek, perhaps unwittingly sowed doubt in my mind. I’ve never had a need to replace the Sensor with something better, to divorce it. Like everyone else, I appreciated what other models had to offer, sometimes even admired that, but not enough to make me wonder what would happen "if". The THERIAA is not without its flaws as there is no such thing. Analog master tape played on a top Studer sounds more dynamic and has an even better representation of holographic space and fewer artifacts that make it difficult for us to "suspend disbelief." The best tube preamps have better saturated midrange. However, the Polish preamp does it all at least very well, combining everything into one coherent whole. We have no need to analyze, to try experiments; we are simply lost in contemplation.

Testing Methodology
Testing had a character of A/B comparison with known A and B. I listened to whole albums as well as individual tracks. The unit was directly compared against the Manley Steelhead and the RCM Audio Sensor Prelude IC. I used two turntables: Transrotor Rondino TMD with the SME 5009 tonearm and Dr. Feickert Analogue Blackbird with the 12" Jelco tonearm. I used cartridges from Miyajima Labs, the Kansui and the newest, ZERO mono, as well as the Air Tight PC-1 Supreme. The SME tonearm was coupled via Siltech Classic Anniversary Phono interconnect. The preamplifier was seated on the Acoustic Revive RAF-48H air platform and powered by Acrolink Mexcel PC-9300 power cord.

Specifications
Type: Dual monoblock phonostage
Gain: 76 dB
RIAA Linearity: +/- 0.1 dB (20 Hz - 20 kHz)
Input Mode: Balanced via XLR or unbalanced via RCA
Nominal output level: 2 Vrms
Maximum Output Level: 9 Vrms
THD: < 0.1%
Input capacitance: 100 pF
Input sensitivity: 0.2 to 5 mV, adjustable in 8 steps
Input impedance: 20 Ohms - 47 kOhms, adjustable in 7 steps
Power Supply Enclosure: 4 mm aluminum profile with 5 mm front and rear panels, painted black.
Preamp Enclosure: 10 mm and 5 mm brushed, black anodized aluminum 
Front: 10 mm brushed aluminum, anodized black or natural aluminum color
Feet: stainless steel, mounted flexibly.
Indicators:
∙ Error, indicating DC current on input,
∙ Overload, indicating input overload,
∙ Wait, on during system testing,
∙ Power, indicating power-on, separately for the left and right channels.

Weight: amplifier unit - 9 kg, power supply - 4.5 kg
Shipping weight: 17.5 kg
Price: €9800 including VAT

Company Information
RCM S.C.
40-077 Katowice
ul.Matejki
Poland

Voice: 32 206 4016
Fax: 32 253 7188
E-mail: rcm@rcm.com.pl
Website: www.RCM.com.pl