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Holfi Xaurus NFB Rex - CD player

Uncontrollable urge!

[Holfi Xaurus Rex CD player]

Holfi Xaurus NFB Rex CD player

[Italian version]

Product: Holfi Xaurus NFB Rex - CD player
Manufacturer: Holfi - Bernic ApS - Denmark
Approx. price: 3.250 Euro/$
Reviewer: Lucio Cadeddu - TNT Italy
Reviewed: January, 2003

Holfi is a Danish Company which likes to think and design different. A quick look at their website unveils some peculiar features shared by all the products in their catalogue. For example, they strongly believe in zero-feedback (NFB) circuits and battery-powered power supplies.
This Xaurus NFB Rex - being their top of the line CD player - makes no exception: it is a multibit CD player with several, interesting and - dare I say it - weird features: firstly, the power supply uses an outrageously high filtering capacity, at 50,000+ uF!!! It is hard to see such a large filtering "power" even on big and powerful power amplifiers.
Secondly, this power supply is split in two (two transformers, that is): one feeds the batteries and another one the CD transport, motor and servos. Then 4 lead-acid rechargeable batteries power the analogue section and the D/A converter.
These batteries ensure the most sensitive audio circuits to be FREE from RFI and interferences from the mains supply. An automatic circuit keeps them permanently charged so expected lifetime exceeds 10 years.
The output stage is a single-ended zero-feedback class A analogue amplifier, based on current amplification so to keep the output current from the DAC as clean as possible. The signal passes through 2 transistors only, before reaching the 2 gold-plated WBT output RCA's.
Even the CD transport has been slightly modified. Two green leds placed above the transport should help absorbing the laser reflections from the disc. According to the complete Holfi literature this way there should be less reading errors. The CD transport (a Philips CDM 12.65) has been custom-damped for improved performance.
A similar transport can be found on quite inexpensive commercial CD players as well as the DAC chip, a Philips TDA 1545A which is used on entry-level Philips and Marantz machines (Philips CD 723 and Marantz CD 4000, to name a few).
The TDA 1545A is claimed by Holfi to be a multibit (16bit) converter, actually it is of the Continuos Calibration type, a kind of hybrid system between single and multibit. Sadly, the Philips literature reports it as "eminently suitable for use in (portable) digital audio equipment". Refer to the Philips SemiConductors page for other details. At 4x oversampling, the chip operates at double-speed.

The whole steel cabinet has been internally damped via heavy bitumen sheets (something tweakers know very well). The front panel is made out of solid wood (apparently, walnut).
As you can guess, this CD player is a very heavy one, at 12 kgs (25 lbs)!
A standard digital output is included...but it's INSIDE the CD player! Yes, the Holfi designers think the digital output is sonically harmful so they decided to connect a 75 ohm resistor (to simulate the SPDIF standard load) and hide the output inside the player. So if you want to connect an outboard DAC you need to open the CD player and perform some kind of _not easy_ digital surgery.

The Holfi Xaurus NFB Rex comes equipped with a complete remote control that allows almost every kind of operation, volume level adjust included. The power-on switch is placed in the rear since the unit is supposed to stay permanently on (so to extend batteries lifetime). The mains power cord is datachable.

The Holfi Xaurus NFB Rex - thanks to the Philips transport - should be able to play every kind of Compact Disc (CDs, CD-R's, CD-RWs etc.).

[Holfi xaurus NFB Rex - inside view]

Xaurus Rex, inside view: see the two sets of batteries (right and left)

These are the claimed tech specs:

As you can see from the specs above, the output impedance is 470 Ohm and, surprisingly, the recommended load is 800 Ohms (or higher). This means, in some sense, you need a Holfi preamp or integrated amplifier to put the Xaurus Rex under the best possible operating conditions. And that's exactly what I did: tested the player via different preamps (with standard 47 kOhms input impedance) and finally with its natural partner, the big Holfi Integra 88 SE integrated amplifier (soon on these pages).
I've lived with the Holfi pair for almost 6 months, I've tested them against various CD players and amps and partnered with 5 different pairs of loudspeakers, at least.

Uncontrollable urge!

Roughly speaking, I'm attracted by people who think different. Perhaps because they remind me my radical choice to create a no-advertising HiFi mag on the web (the one and only, worldwide), perhaps because I've always hated mass-oriented designs and products.
This Xaurus Rex, as you may have noticed from the description above, is full packed with both innovative and well-known tweaks that put it into a league of its own. Not a surprise that even its sound is quite different from that one may expect.
Indeed, judging from the outside (tech specs, size and weight) one may expect a big, solid and aggressive sound, with plenty of bass and grunt. Not so.
Let me start from the bottom :-) i.e. from the bass range. It is quite lightweight, dry and extremely controlled. It is not a wrong bass, it is just thin, considering the high end ambition of this player. So the bass shows good articulation and precision but depth, impact and weight are definitely lacking.
A quick and casual A-B comparison test with a good old Revox B226 - not famous for its powerful bass range - proved how light the bass performance of this Xaurus is, especially when used with a standard preamplifier (more on this later).
It is not that kind of difference that takes hours of self-meditation and Yoga exercises before hearing it. You don't need to offer human sacrifices to the Powers That Be. It is something SO CLEAR that my wife noticed after the first A-B comparison (and, of course, she knew NOTHING of the two players involved).
More or less, the same applies to the mid-bass: clean, tight, precise and...light. Big bass and impact fans may not appreciate the Xaurus, since this player does NOTHING to impress the listener, at least in this portion of the audio spectrum.
Generally, this weight-watchers bass performance makes certain musical genres totally unappealing and somehow unattractive. Things get only slightly better when the Holfi Xaurus is partnered with the Holfi Integra 88 SE integrated amp and its matching 800 ohm CD input.

Mids and highs are far better, hence voices and string instruments appear nicely and naturally reproduced. The performance is very detailed and rich. Hence, one can enjoy every nuance which is recorded into his favourite discs.
The highest portion of the audio spectrum, from time to time, becomes tizzy and hyper-detailed. With certain records the overall sound appears a bit too "lively", especially when dealing with pizzicato's and cymbals' upper harmonics.
Somehow, this CD player reminds me a compact minimonitor loudspeaker, extremely precise and clean in the mid-high range, with an extra-dry bass and, from time to time, a too vivid high range.
Frankly, perhaps because I was expecting a totally different performance - considering the tech specs and the claims of the Holfi literature ("...smooth and relaxed sound") - I must admit this player has shocked me for a long while. Actually, I'm not 100% sure I can justify, sound-wise, the steep 3250 $/Euro price tag.
It is extremely precise in the mid-high region, but lacks authority and weight in the bass. Definitely not something one expects from a 3,000+ $ machine.

Micro & macro dynamics

Considering the excellent rigour and precision, one may expect this player to be extremely fast and well-paced. And so it is. Its musical performance is quick, well tempo'ed and rythmic. Had it more weight in the bass I would have given it a standing ovation, with respect to this parameter. It preserves the natural tempo of the Music, it is not "faster" or "slower", just metronomically right.
For this very same reason its dynamic performance is good and the player succeeds reproducing big "jumps" (of level) with ease. Only in overcrowded situations (big choirs and large orchestras playing fortissimo's together, for example) it seems to show some weakness.
Since it does not have that "big" sound one may expect, its dynamic performance does not impress, at first sight. Once the brain learns to equalize (adding bass, that is) you start to understand everything is done right. It will not shake the walls of your listening room but it will get the job done honestly.
Now it should be clear why I choose "Uncontrollable urge" as subtitle for this review. The dynamic behaviour of this player reminds me of something that needs to be done, quickly and precisely. As an established tradition here, I've taken the title from an album, one of those I listened to during the tests. It is the first track of the album "Q: Are we not men? A: We are Devo", a _no-audiophile_ small masterpiece of a band from Akron (USA), the Devo (1979 on Virgin Music).

As absolutely logical, from what's been said above, the Danish player shines literally in the microdynamics department, with loads of tiny informations brought to you as it was the easiest task in the World.


Exactly like you may expect: the contours of the instruments and of the players inside the 3D virtual image are extremely precise and focused. So is the stability of the stage itself, too.
Width and height being at their best, depth is only a bit sacrified because of the "forward" character of the Xaurus. If you like a slightly "monitor" effect, this player will satisfy you.
Ping-pong stereophonic effects from left to right and viceversa are reproduced quickly and precisely. This means the player has an excellent channel separation and impulse response.
Holfi recommends using Holfi (soft) feet under the player for better performance. Actually, with these feet under the player, the soundstage becomes a bit more "even" in the 3 dimensions.

Some advice

The Holfi Xaurus NFB Rex is a very heavy unit, so be sure to place it on a stable platform or table. Use soft feet (like the Holfi ones) to get a slightly better sound. Leave it permanently on and do not listen to it until the batteries are 100% charged....or you'll be disgusted.
Holfi recommends 2 hours of warm-up before playing. This equals to leaving the unit permanently on :-)
Considering the low power consumption (10 watts), let me strongly recommend leaving it on.
Partner it with a low impedance input preamp or integrated amp to get the best sonic performance. As recommended, an Holfi Integra 88 SE seems to be the ideal partner.
The solid wood fascia needs some extra care, so clean it with suitable products (if in doubt, ask your wife or mother :-)) and be careful: it is easier to scratch a wood panel than an aluminium one.


Manufacturing and finish.
The Xaurus Rex is built like a tank. Heavy, massive, solid and well finished, this player seems built to last. Zero plastics parts, only thick steel and solid wood. From a mere aesthetical point of view (FWIW), the match between the solid wood fascia and the black cabinet might not satisfy everyone's taste. It didn't satisfy mine, for example. It may be your cup of tea or a punch in your eye, up to you to choose. For sure, it is more difficult to integrate it into an existing HiFi set or furniture.
Just minor complaints: the player can be stopped and put in stand-by mode only by remote. The four swtches in the front just allow load/eject, play, tracks skipping. NO STOP! I definitely need STOP - PLAY - EJECT in the front panel. You always need the remote but the remote can't do everything. For example, there's no "Eject" (load/unload) button on it! So to stop the player and extract the CD you need to operate both with the remote (to stop) and the eject button on the unit. If you have to put the CD into its case, you need a third hand or throw away the remote. Two extra buttons on the front panel ARE the solution. Please, please, please, give us a STOP and a STAND-BY button! :-)
Finally, the general power-on switch in the rear can be a nuisance.

The WBT output RCA's are cleverly spaced, allowing the use of massive RCA plugs but there's a minor problem: they are placed exactly at the center of the rear panel so switching cables can be difficult. I prefer those on the right corner, as usual. This allows easier operation with cables without moving the unit.
The stock feet should be replaced by Holfi feets, as the Company recommends. So, why not install them as default? On a 3,250 Euro/$ CD player it sounds just logical to me.
Also, on a similarly priced machine, I'd expect something better than an el cheapo CDM 12.6 transport (there exists a CDPro2, let's use it!). So, while the player looks "luxurious" outside, it reveals some saving in the inside. Internal cabling isn't exactly how it should be on a high-end machine (see pic for details) and even the power supply transformers look damn cheap. I may be damn wrong, but the one that feeds the digital transport and servos is the same one can find inside the Philips CD 723.
Finally, the "fake" digital output. Either you put it or not. A black hole in the rear with the writing "Digital output" sounds bizarre, to say the least. I agree a digital output is a nonsense on this player (considering its philosophy) but, then, do as others do: avoid digital out at all (Naim, for example).
That hole in rear, protected by a platic cap, can lead a customer think he can REALLY use a digital out in this machine. Not good.

Sound. This is not the player for deep bass freaks. Things get better with the natural Holfi Integra amplifier but sometimes the sound tends to be excessively dry and thin. The Holfi feet help a little in this department.
The Xaurus NFB Rex, considering overall sound and materials (transport, DAC, transformers...) is quite expensive, at 3,250 Euro/$. Do not forget the competition isn't playing hide and seek in this field. Today, below 3,000 Euro/$, one can find digital players (or transport + DAC combos!) equipped with CDPro2 transports, 24/192 upsampling and all the latest goodies in the digital domain.
The required 800 Ohm input impedance isn't an industry standard (47 or 50 kOhm are, instead) so you won't find a preamp or integrated amp (except Holfi's) that suits the Xaurus needs.


In a world of mass-designed and marketed Far East HiFi components, even rebadged by audiophile brands (!!!), one may welcome a CD player that dares to be different. Different by design, looks and sound.
For sure it is not everyone's cup of tea, but definitely a player that stands above the competition for many reasons. In my humble opinion it does something very good, something else...uhm...just so-so but, in the end, I've found it way too expensive.
A personal and careful listening test is mandatory, possibly with a Holfi amplification.

Manufacturer's comment

Thank you for taking the time to review our products.

I'm sorry that the bass is not to your liking. We do not in general like what we most often hear in this end of the frequency spectrum from most other products - and yes we find that most products are too "fat", emphazising the area 60-80 Hz. This works great with not too expensive systems and with systems using two-way bookshelf speakers regardless of price range. Our Xaurus however is made for playing in set-ups using fullrange speakers (or alternatively bookshelf/subwoofer systems).
We hope to see you in your FIAT up here far to the north (that's a good long drive, but come in the summertime) and we would love to demonstrate what we think is a suitable system for the Xaurus. You will not miss bass....
We are happy that you are at least positive to the control and detail in the bass - that is what we set out to accomplish.
We can be a little sorry that we did not send you one of our less expensive CD-players as they have a little more fatty character (we tune the final sound quality to the what we believe gives the highest musical satisfaction when combined with products obvious to the price range).
We look forward to the review of the Integra 88, which should be much more to your liking.
Thanks again...and hope to see you sometime.
Comment by Peter Holstein - HOLFI

© Copyright 2003 Lucio Cadeddu - http://www.tnt-audio.com

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