I am emotionally involved with Leben. Although I have never met its owner and founder, Mr. Taku Hyodo, on some level I feel I am a kind of his “follower”. For years, I have been using his devices, first the CS300 amplifier, then the CS300X, followed by the custom CS300X specially modified for me, which bears his dedication on the back. These are actually not the only Leben components I used, because for a long time the basis of my system had been the RS28CX preamplifier, very warmly remembered by me. As a matter of fact, I have never seen a Leben product that I would not like or would not understand. Naturally, I have my favorites, with my CS300X [Custom Version] leading the pack, however, the CS600P and the CS1000P power amplifiers were so interesting that were it not for space constraints, I would have bought one of them for myself. Leben is a small company. New products from that manufacturer appear relatively rare. The last to have reached us was the CS1000P power amplifier. Until now, that is. Behold, Mr. Hyodo decided to replace his biggest hit so far – the CS300XS, introducing in its place the CS300F.

From the outside, it is hardly different from its predecessor: it is still a small device, measuring 360 x 270 x 140 mm and weighing just over 10 kg, with a small power pentode based push-pull output stage. However, while previously they were EL84 (Mullard [Version X] or Sovtek [Version XS]), now they are replaced by long-life General Electric JAN-6197 (6CL6), with low microphonics and very low distortion, designed primarily for use in computers. These particular models were manufactured for the U.S. Army (JAN = Joint Army Navy U.S.). It is a power pentode with 9-pin octal base. In a push-pull class AB, the tubes push 15 watts at 0.7% distortion. Input tubes are also different: in place of NOS General Electric 5751, Leben now employs no less unique 17EW8 (HCC85 equivalent) dual triodes from Hi-Fi, a Japanese company. Therefore, it seems true what we read on the Polish distributor website, that it's really a completely different device, sharing with its predecessor only the general idea and the enclosure.

TESTING METHODOLOGY

Since I use the CS300X [Custom Version] every day, the most important comparison concerned that model. An obvious problem at the outset is that my custom version is completely different from the stock model. It has been specially designed for the 6R-P15 pentodes from Toshiba, which results in the output power of about 8 W (the "regular" version is rated at 15 W), and it features different coupling capacitors (the V-Cap CuTF); its feet were changed for the CeraBall from Finite Elemente and its fuse for one from Create Audio (see HERE). Finally, Mr. Eugeniusz Czyżewski, owner of Linear Audio Research, made a modification improving the symmetry of the output stage (see HERE). In order to remain “on the ground”, I briefly borrowed a classic version of the CS300XS.
The test involved listening both with speakers and headphones. As we know, integrated amplifiers from Leben are also excellent headphone amplifiers; actually, in my system I use it mainly in this way. For testing purposes I used the following headphones: Sennheiser HD800, AKG K701, Beyerdynamic DT990 Pro (600 Ω, vintage), DT770 Pro Limited Edition 32 Ω, HiFiMAN HE-500 and HE-300. Description of most of them can be found on “High Fidelity” pages (in the archive section). The amplifier sat on the Base rack, without extra feet or spacers, and was powered by the Tunami Oyaide GPX-R power cord (see HERE), from a dedicated mains outlet and the Oyaide MTS-4e power strip. The testing had a character of an A / B comparison, with the A and B known, using 2 minutes long music samples. In addition to the Leben CS300X [Custom Version], the reviewed amplifier was also compared against the reference two-piece amplifier – the Ayon Audio Polaris III [Custom Version] preamp and the Soulution 710 power amp, as well as the Ayre AX-5 integrated amplifier. For comparison in the headphone amp mode I used my Leben, the Phasemation EPA-007 and the HPA-21 headphone amplifier from Bakoon Products, which review will be soon published.

SOUND

A selection of recording used during auditions

• Bach, Golberg Variations, piano: Glen Gould, CBS/Sony Classical/Sony Music Entertainment Hong Kong, 440092, “The Glenn Gould Edition, No. 0197”, gold-CD (1982/2013).
• Bach, Violin Concertos, Yehudi Menuhin, EMI/Hi-Q Records, HIQXRCD9, XRCD24, CD (1960/2013).
• Dead Can Dance, Toward The Within, 4AD/Beggars Japan, WPCB-10077, „Audiophile Edition”, SACD/CD (1994/2008).
• Depeche Mode, Home, Mute Records, LCDBong27, maxi-SP CD (1997).
• Diary of Dreams, The Anatomy of Silence, Accession Records, A 132, CD (2012).
• Eddie Costa Quintet, Eddie Costa/5, Mode Records/Muzak, MZCS-1132, “Mode Paper Sleeve Collection vol. 3”, CD (1957/2007).
• Frank Sinatra, Where Are You?, Capitol Records/EMI Records, 4969932, “Sinatra. The Capitol Years [Box]”, CD (1957/2008).
• Frank Sinatra, Where Are You?, Capitol Records/Mobile Fidelity, UDSACD 2109, “Special Limited Edition No. 261”, SACD/CD (1957/2013).
• John and Vangelis, The Friends of Mr Cairo, Polydor/Universal Music Japan, UICY-9376, “Rock Legends Series. Limited Edition Paper Sleeve”, CD (2003).
• Led Zeppelin, Celebration Day, Swan Song/Atlantic/Warner Music, 79688-1, 2 x CD + Blu-Ray + DVD (1981/2012).
• Michael Jackson, Thriller. 25th Anniversary Edition, Epic/Sony Music Japan, EICP-963-4, CD+DVD (1982/2008).
• Milt Jackson Quartet, Statements, Impulse!/Universal Music (Japan), UCCI-9088, “More Best 50”, No 38”, CD (1961/2001).
• Pat Metheny Group, Offramp, ECM/Universal Music K.K., UCCU-9543, “Jazz The Best No. 43”, gold-CD (1982/2004).
• Pinky Winters, Pinky, Vantage/Sinatra Society of Japan, XQAM-1044, CD (1954/2010).
• Porcupine Tree, Deadwing, Lava, 93437, CD (2005).
• Sarah Vaughan, After Hours, SME Records/Sony Music Entertainment (Japan), SRCS-9515, “Master Sound”, CD (1955/1998).
• Wilki, Wilki, MJM Music PL, MJM5236D, „specjalna, dwupłytowa edycja”, 2 x CD (1992/2012).
• Monteverdi, Quinto Libro De Madrigali, Concerto Italiano, Rinaldo Alessandrini, Opus 111, CD (2000).

Japanese editions of CDs and SACDs are available from

Auditioning products from manufacturers that are particularly close to our heart is marked by certain ambiguity. On the one hand, it is savoring the familiar company ethos, its visual design, sound, and the joy of seeing the next product bearing the logo we care about – all that confirming our earlier choice. However, there is also anxiety, inner trembling, a not fully articulated question about what is left of the glory and honor remembered by us – and that introduces into our joy an element of uncertainty or fear. Surely, not everyone reacts so emotionally to audio devices, certainly not to all of them. In the case of Leben and me, it is exactly like that.
The news about a new version being designed, the fourth already, of the CS300 amplifier (the former line-up: CS300, CS300XS and CS300S, not counting the limited edition CS300XS [Custom Version] made especially for me), for the first time, however, differing from the predecessors by type of the employed tubes, not their manufacturer. And that means a completely new circuit design and a great unknown concerning the sound. Even though the external differences between the earlier versions and the F are minimal. Straight up, I can say that the CS300F does not disappoint but brings no surprises, either. It does not disappoint, because it's the sound of the same class as the CS300XS, with somewhat differently placed accents and a slightly different expression. It brings no surprises, because despite fear that is what I expected: refined sound. .

CS300F vs. reference system

One enters the world proposed by Mr. Hyodo gradually. We do not jump straight into the deep end, or get immersed right to the top of our head, or go mad. The closest term to describe what happens to us is "to get soaked in". I think that is, first of all, because the sound of this device seems slightly dark. There is no cascade of sounds and super-selectivity. We get “connective tissue” between the speakers, a saturated sound of which we need to "fish out" the details. Upper treble is realized in such a way that although on the type of recordings like Billy Jean by Michael Jackson, Useless by Depeche Mode from their maxi-single by the same title, or Arriving Somewhere by Porcupine Tree the cymbals were clear and had a proper attack, it was their slight rounding, somewhere at the edge of perception, that gave them greater vividness and protected them from being garish or aggressive. Such problems, resulting in the music losing its meaning and becoming just a collection of sounds, will never occur with the Leben.
Although treble is not particularly emphasized, we will not perceive that as a "loss". This is characteristic of the best audio devices in which their designer tries to model the sound in such a way as to exploit their full potential, to implement his vision of the sound, masking the most common problems of recordings. Especially in this regard I listened to a lot of CDs with vocals in the lead role, and one thing we will never say about the CS300F is to call it "problematic". In any sense of the word. This is not a "simple" sound, as we are talking about a refined piece of equipment and a clear designer’s vision of the world. This is an amplifier that tries to protect the listener from the recordings’ elements we usually call "garbage", but at the same time does not force it, nor does it primitivize the presentation, bringing it to a common denominator.

One of the main features of the Japanese amplifier is its excellent resolution and, hence, its ability to differentiate. Both have their limitations. But they also take precedence over everything else; even when we get the amplifier to the point of “giving up”, it doesn’t do it abruptly and get unpleasant. We “accompany” it in this problem, as if it was someone close to us – such is the power of persuasion of its designer’s idea.
What is more important, however, is its ability to move freely in the musical material, from which it tries to bring out the best. Even from the records we give up on at the outset due to our prejudices. That is how I, initially, assumed the "inferiority" of the 1998 edition of Frank Sinatra’s Where Are You from the Capitol Years box set, and the "superiority" of its recent re-edition from Mobile Fidelity. The comparison was not entirely valid, because the older edition is stereo (it was the first Sinatra’s solo album in stereo), and the new version is mono. However, on the former the first track I Cover The Waterfront is a mono recording (an exception). What did I hear? Both sounded very good. The Mobile sounds clearer and more coherent, with a slightly better resolution. The 1998 digital remaster, on the other hand, has a nicely drawn "body" of the singer who is shown more in the front. Which version is better, which is the right one? Each of them has something valuable, but they both sound worse than the vinyl edition from Mobile Fidelity. The point is, however, that Leben allowed a relatively free migration between them; after several changes their individual sonic characters were clear, yet it did not let either sound bad or even significantly worse than the other. As if it brought out the best of them.

The amplifier offers a strong, low bass and a very nice dynamics. Its moderate output power does not even hint at what can be heard from such large speakers, as the Harbeth M40.1. In fact, its momentum, vividness, strong bass that is not loose closely reminded me what I heard from the Ayre AX-5 amplifier, despite the fact that American integrated is a thoroughbred, powerful, solid state design. The tiny Leben can produce a similar volume of strong, saturated, focused sound as a large solid state amplifier. At a short listening distance, of course. Electronic music, here mainly Depeche Mode, also sounded great. There was groove, oomph and superbly-controlled highs. I’ve already mentioned the latter, but each time I’d make the same observation: excellent vividness and balanced color.

Dynamics is related to the color presentation – a little dark, but very vivid and differentiated. Glen Gould’s piano was exceptionally fast, but also set in the structure of the song, so much that one could hear his playing technique. Pianist’s humming was shown in a separate plane, although in terms of 3D imaging, enveloping the listener in sound, the CS300F does not show anything spectacular. The sounds come to us from between the speakers and from the sides, only rarely from behind us. Even though we know that the sound engineer placed them there. I think this is due to a slightly withdrawn upper midrange and not as large volume of the sound as, e.g., the CS1000P. This is where you can hear a moderate output power of the device. Gould’s piano had great color, dynamics, was credible, but its size was smaller than with the reference system. The same was with Sinatra’s and Jackson’s vocals. Interestingly, Porcupine Tree recordings were large, expansive - but that's because they were so intended. Their warm color helped in pushing the sound forward.

CS300F vs CS300XS [Custom Version]

That, how the CS300F sounds on its own, compared to the reference system, other Leben amplifiers, and devices from other manufacturers, is important. One could even say, basic. I am however convinced that for a large group of the readers, at least for those who own previous versions of this amp, an equally, if not more, important is information about how they compare to each other, apart from the absolute quality of the amplifier.
Message no. 1: This is the same "chic" – both amplifiers sound dynamic and large, for their power output; they are great in showing the "guts" of the recordings, in their emotional value. In this respect, nothing has changed - there are very few amps for that kind of money that can sound so well with the Harbeths.
Message no. 2: the sonic modification within the same paradigm is, however, significant. The CS300F sounds more expansive, closer to the listener. Its bass is bigger (without touching the "bass boost" dial) and seems deeper. Consequently, the recordings sound more powerful. At the same time, however, they are not as communicative, they do not have as well differentiated bass and midrange. I’ve mentioned that the new Leben brings out the best of each recording. It turns out, however, that at the same time it makes them somewhat similar to each other. While earlier the two versions of Sinatra’s album were equivalent for me, now the analog remaster from Mobile Fidelity was more differentiated, had a different emotional temperature; the box set version, in turn, remained all the time on one "tone" and also had a slightly lighter upper midrange – the thing absent in the Mobile version (it is an ultra-smooth sound).
Without a doubt, it's part of the sound "setting" in the "F". Here the emphasis seems to be on creating a full sound, one that is pleasant with any type of material. And that is very impressive! Even knowing what it results in (a slight uniformity of bass), each time after returning to the new amplifier from Mr. Hyodo it was a pleasure to sit down and to listen again to the same recordings.
The color has changed – it is now set lower, deeper, with a more precisely delineated bass – as well as the presentation of recordings, which is now closer to the listener and darker. The amp doesn’t lack treble, it's not that! The upper midrange is so smooth, and the lower midrange so boosted that it covers to some extent the higher harmonics. They are there, since that is a complete sound, but they have a smaller role to play than with the CS300XS [Custom Version].

CS300F as headphone amplifier

I felt very comfortable listening to the new amplifier. It "blended" easily with the Harbeth speakers and I am convinced, or actually I am sure that it was such speakers that it was initially, still a prototype, auditioned with. Anyone who has once heard that pairing (or a combination with speakers from Spendor, the Reference 3A, and with some JBLs) will be enchanted by the sound culture and the capabilities of such a small device. But I cannot deny that for me the Leben CS300 (and all later versions) is primarily a headphone amplifier. I didn’t predestine it for this role, it just came out "in the wash": this is one of the best, if not the best, headphone amplifier I have come across. Sennheiser HD800, AKG K701, Beyerdynamik DT990 Pro (600 Ω) – with the Leben they all show the best they have. The only exception are the planar HE-6 headphones from HiFiMAN, but they need a whole power station to drive them. I will some time return to this subject.
The F model sounded with the headphones exactly the opposite of what I heard from the speakers; lighter and clearer than the XS [Custom Version]. The latter sounded deeper and darker. When the record is light, as it often happens, I use the "Bass Boost" knob and everything is fine. I can hear that it's an addition, a manipulation, but I accept it with the benefit of inventory because it's worth it. Adding 3 dB in the F resulted in too much weight of the sound. I assume that the gain level of the selected frequency is the same in both amplifiers, yet the effect is completely different. Boosting the bass in the new amplifier resulted in a boomy sound that goes far beyond the limits of my acceptable compromise. The exception was a really quiet playback - then it was perfect. Unfortunately, I cannot explain this phenomenon.
Nevertheless, it is generally still an excellent amplifier with fast, accurate sound and excellent imaging. What was simply good with the speakers, that is showing the bodies and selectivity, with the HD800 headphones was outstanding. The emphasis is on upper midrange, so one must choose the source carefully. If we overdo clarity and selectivity, the vocals will get too light and slightly strained. Everything else, however, is a sheer delight – depth, dynamics, resolution, and

Conclusion

Both amplifiers come from the same father, which can be seen and heard. I have no doubt that he loves them equally. To someone who doesn’t know them, they will seem very similar. However, if we know the older one, the new design will be significantly different. It offers a more focused, deeper sound with an even more saturated upper midrange. Resolution and selectivity is better with the older version. So is imaging, which shows how the device copes with the rendering of space and components in space. They are still, however, the same emotions, depth, dynamics, and "drive". Low bass, while maybe not quite as selective and not as well differentiated as in my version, has more body and with 99% of speakers, except the most expensive designs, will perform better. The sound with the headphones is lighter, with a nod to upper midrange, but it's still a top headphone amplifier. It would be best to have both amplifiers. The F version delights with purity and clarity, even when playing loud.
Owners of the older version should give the new one a listen, to check whether its color would not better integrate with their speakers, especially that the "F" shows the events closer to us, in a more tangible way. If for some reason we do not yet have any Leben at home, then it is necessary to listen to it, to put it on the shelf and to live with it for a while. This is an amplifier that "gets" under the skin.

The amplifier receives the RED FINGERPRINTS award

DESIGN

1970s in audio can be seen not only in the techniques used back then, but first of all in industrial design. Nobody will mistake Luxman from those years for anything else, just as nobody will do that with Accuphase, Mark Levinson, Marantz and many other companies. Leben makes a direct use of those experiences, showing that the years spent by Mr. Hyodo at Luxman left him with good memories and that he considers those years a "golden" period of tube technology. Although his favorite tubes are KT66 and the circuit known from the Quad II amplifier, it is the small EL84 that brought him international fame. In the CS300 it was a military version of Sovtek EL84, with 5757 from General Electric in the input and driver stages. The CS300XS sported in the output stage a rare version of the EL84 from Mullard (NOS), which made it a limited edition, and the CS300S marked a return to Sovtek, retaining modifications, better components, connectors, and controllers first introduced to the CS300XS.
According to the manufacturer, the new amplifier employs a completely different set of output tubes, and thus a completely new circuit design. We learn that for the first time in the history of audio it uses long life, very low distortion tubes from General Electric, the JAN-6197 (6CL6), designed primarily for use in computational systems (logic), in other words - computers. These particular models were manufactured for the U.S. Army (JAN = Joint Army Navy U.S.). The JAN-6197 GE is a power pentode with 9-pin octal base. Working in push-pull class AB topology the tubes push 15 watts at 0.7% distortion. The driver tubes are also different and unique: a pair of 17EW8 (an equivalent of HCC85) low-power dual triodes from Hi-Fi, a Japanese manufacturer. In other words - a complete change.

Looking at the unit from the outside it's hardly noticeable. The only change seems to be a different power switch and the fact that we now have one blue LED instead of previous two - green and red - indicating that the amplifier is on. I know that blue colored LEDs are extremely popular in audio, but I do not like them and "blue" for me doesn’t go well with the 1970s at all. Red and green on the other hand do that perfectly. After a closer look, however, we can notice a few other details, seen for the first time. A different color (a shade of purple in place of gold) of the top and bottom walls, a slightly different way of mounting of the largest knob, other RCA connectors (not in terms of better quality, which is still not particularly refined, but of a different manufacturer) and feet. Until now, all Leben amps sported plastic feet with golden rim. The new CS300F has the same feet, but they are now double. This way they resemble the Finite Elemente Cerabase Slimline, but they are not!
The amplifier is housed in a classic enclosure, similar to solid state devices. The interior is divided with a horizontal plate, with the tubes and transformers mounted to the top of it. The transformers are very similar to those used in the CS300, except that the speaker transformers now feature a paper label in place of metal plates, and the power transformer is marked PT-305A (previously PT-300A). We also see that there are no additional resistors and a part of power supply section introduced to the XS and left in the S. The quality of the connection terminals is the same as in the XS.
Turning the input selector and the Bass Boost knobs we feel that the switches are slightly inferior to the ones in the XS. On the other hand, the potentiometers are the same, good Alps (malachite). A new feature is the screen separating the potentiometers and the switches from the tubes. Earlier versions did not have that. I have not mentioned it yet, so let it be a bonus for those who have stayed thus far: the CS300F hums much less than all the earlier versions. Mr. Eugeniusz Czyżewski, owner of Linear Audio Research, tried to control it through an appropriate modification in my unit (see HERE), but he said that further reduction of hum would be difficult due to the proximity of the power transformer and the tubes. But I can see that Mr. Hyodo was able to take some control over it with the said screen.

Wiring, as usually in Leben, is point-to-point without any PCB. High quality resistors and nice, polypropylene coupling capacitors have been used throughout. The cathode capacitors are from Elna (input and driver tubes) and Nichicon Fine Gold (power tubes). Capacitors from the same manufacturer can be found in the anode voltage filter - four capacitors in several serially connected "Pi" filters, and one in the voltage filter. Star grounding is used, and the rectifying diodes (half-wave rectifier) are bypassed with polypropylene capacitors. The whole looks very similar to the previous versions, except that the electrolytic capacitors in the power supply and the rectifier diodes have been changed.

A classic layout, assembly, and beautiful workmanship. The amplifier does not come with a remote control.