 Amplifikator, the brand name for the products of the company Radicon, is one of the most interesting Polish manufacturers. As one of very few it proposes a complete sound reproduction chain. It started with an integrated amplifier, which two incarnations we have reviewed here, first the Amplifikator 2003, and later its successor Model G. Those amplifiers were always the visit card of the company. But it turned out, that the company also has some interesting speakers to offer: Etera Alumina and Etera Fibra. When the phono preamplifier PreAmplifikator appeared the only thing missing was a digital source. Against appearance working on a CD player begun shortly after the first… Amplifikator was made. And the project has its years already. But it seems that to be able to present something verified to the public, something that the designer can sign with both hands, a small manufacturer that has no big financial capabilities, must invest something he has plenty of: time and knowledge. And those elements, as turns out from the tests and the project start date, are in Mr. Tomasz Burski, the constructor of the Amplifikator, aplenty in his portfolio. It seems, that it is hardest to design a CD player. This thesis is supported by life itself: there are a few dozen Polish companies producing loudspeakers, about the same amount of cable companies, a dozen constructing amplifiers, but a player is proposed only by a few – I think that mature projects are available in a number of companies that could be counted using the fingers of just one hand. In theory we could add to those the manufacturers of D/A converters, but they are just an addition, because in a CD player there is a marriage of mechanics and electronics, and that is a hurdle, that cannot be circumvented, jumped over or ignore.. )
Because a new CD player of Polish origin is an absolute rarity, because the making of a CD player 25 years after the format was launched, in times when dense formats DVD-Audio and SACD came and went (I am talking about commercial usage), in times when Blu-Ray and HD-DVD are in reach, even denser formats, capable of of carrying the DXD format with 24bits and 384kHz in many channels, anyway in times when a CD can look like an anachronism, the stem Amplifikator has taken can look not sensible. However, life is not a 0-1 world, but an analog one, full of halftones and transitions. And that is why the CD is now the only mass format, available for everybody on this planet, and will be alive for at least tem more years, and that has to serve billions of CDs present in our homes. That is the reason of the renaissance of the CD players, and the technique, seemingly ancient, is now mature enough, that we can speak about hi-end sound. And most of all the construction of the Bitofon is so interesting, the applied solutions so untypical, that we cannot be silent about them. Looking inside we see some “patents” like transformers in the analog section, Burr-Brown PCM1704 D/A converters, not in production for a long time, mechanical stabilization of the Philips drive, incredibly worked-out power supply – just to mention the most obvious characteristics. And that is why, looking at the number of choices that had to be made, how many decisions needed to be taken, I have asked the designer, Mr. Burski, to say a few words on the history of the player: “The CD player from the design lab of Amplifikator appears just now in its mature version on the market, although it has a long history. It just did not have luck in its commercial version… The first works started not much after the premiere of the first Amplifikator 2000, actually in parallel with the fine tuning of the visual aspects of the Amplifikator amplifier and in perspective the amplifier – CD set. The CD was based on a “drawer” Philips drive VAE1250, that was a novelty at that time – “for high end audio CD consumer equipment”. A novelty was also the 24-bit digital-analog converters from Burr-Brown PCM1704. The trend was to use the Crystal sigma-delta converters, but this way of conversion (de facto a 1-bit conversion) never appealed me. Theoretical analysis (as could be performed by an engineer raised with analog techniques and sticking to those), literature studies and intuition suggested, that for audiophile components the “stream” PCM type converters, converting directly the 16 (18 or 24) bit words to an output voltage, are best suited. Those are however many times as expensive as even high class sigma-delta converters, but the latter use the technique of multiple feedback loops and for stability need to apply dithering, meaning adding noise in the form of pseudorandom data streams. )
This remind me of the stages in power amplification techniques development (with regard to acoustic signals): first the amplifiers (tube type) without feedback, then with shallow feedback, then the transistor ones with deeper and deeper feedback loops with worse and worse subjective performance and better and better objective performance. And then the return to the linearization of the path without feedback or with a very shallow one. [This is the way the Amplifikator model G was designed - this is one of the secrets of its assets – it employs also a further technology called “predistortion”, meaning as much as shaping of the amplitude characteristic of the subsequent amplifying stages to compensate for the non-linearity, and the output characteristic to become “linear with a small presence of squaring” and this in a broad spread of output power. Here you can see an echo of my other professional occupation, namely radio technology.] Now returning to digital to analog conversion methods – many manufacturers try to combine both technologies taking advantage of the cost and parametric assets (especially with regard to noise) of the sigma-delta and stability of the PCM with its resistance to phase and clock jitter errors. My unwillingness to use op-amps in the signal path of high end audio (now maybe less and less justified…?) – very strong amplification and in consequence very deep feedback – resulted in the fact, that the prototype player the audio section was composed of a converter: current (from the PCM1704) to current of a source without any significant restraints of voltage dynamics made from discrete components, meaning low noise bipolar transistors, a passive LC filter and a current-voltage converter in its elementary form – a resistor (!). The path was terminated with a class A emitter in a DC servo loop. The power supply was based on a toroidal transformer with many secondary windings (8) and independent rectifiers made from discrete components (due to the noise signature). We could say, that in spite of interesting measurement and sonic capabilities (we are talking about the years 2001/2002) this prototype was cannibalized by the work on new models of amplifiers, changes in the programming staff (one of the key basics was the development of our own servo programming and user interface, to not have to use available kits) and a prolonging decisive process. Now it turned out, that Philips stops the manufacture of the VAE1250 drive! So we needed a change of concept. Use a drive mentioned for top loading players, the CD-Pro2M or the less expensive but allowing for a more comfortable handling, plastic (contemptuously) drawer mechanism CD1210-65? And if it lowers the sound quality of the player in a significant way? The decision was influenced by the fact, that the quality of the servomechanism (we are talking about differences in acceptable ranges) do not have a significant impact, if the data is read from the disc by means of a servodecoder clocked by the same precise clock as the digital filter. Thus in the next generation of the player (will its name – Bitofon – appeal to the Polish consumer?) a central clock called a master clock, designed based on a quartz Colpitts resonator with a low noise FET and a quick square wave generator with a separate power supply. According to many specialists such a solution eliminates the need of full metal drives mounted on granite tombstones and pneumatically suspended in metaphysical ether. But I learned to be more cautious in my opinions. We shall see… )
The audio section of the new player, which is here to transfer the output current of the converters to a quality signal on the output socket of the player, was also rebuilt. It is more “passive” as before, made form transistors ingeniously connected to FET transistors in a setting named “trafet”. It integrates the function of an analog filter and a I/V converter (or more precise I/I and R) and in a blueprint it can be reduced to a one stage but balanced current amplifier. The circuit is buffered with a symmetric emitter follower with low impedance. The whole path – from the converters up to the RCA sockets has no general feedback loop. Despite this, the measured parameters are very good. The power supply was also worked out: instead of one transformer there are two now, what should increase the isolation between the digital circuits and drive and the analog ones and the D/A converters. There are also more stabilizers, and those for the audio path are more “discrete” thus less noisy and with better dynamic parameters. Those are also preceded with a more solid amount of filtering capacitors. The enclosure is aluminum-steel with a separated bottom (it resembles the concept of the preAmplifikator enclosure) and with high rigidity. The servomechanism is mounted there with additional elements separating it from the enclosure. Constructing a device like a CD player much attention must be paid to the so called internal compatibility, so that the analog and digital circuits would not interfere with each other. This has a big influence on the parameters of the device, both measured and sonic. That is the reason that layout of the circuits in the enclosure, their connections and the design of the PCBs is so important. Due to the text user interface and the menu available from the remote controller (choice of the digital filter, output level adjustment, programming of the song list) we chose for the 2 line LCD display (for the time being), but a special one: with a black background and red characters.” Sounds interesting, doesn’t it? In the text few important statements and questions were mentioned, so I will reply to three of them that are most important for me. First the drive: I think, that the mechanics is crucial for a CD player. Because I listened to many prototypes of the Lektor from Ancient Audio, I know that even separating the power supply for the laser lens in the new Grand, what in theory should not have any influence, did better the sound greatly. Also from the mechanical side there are surprises – one of those was revealed by an experiment with the Nagra DCD puck (the test will be in the November issue together with the PSA amplifier. This issue will be devoted to hi-end) where even such an unimportant element had an impact on the sound. This was verified by other people, independently from me, and we had similar conclusions, so – even if I will be laughed at – I must say there is something in it. On the other hand, the Philips drive used in the Bitofon is very good, and although it is not the CD-Pro2M, then within its limits, it can do really much. And Mr. Burski took care that it works in the best possible environment. The second issue – the name. I think that Bitofon sounds just great. I do not know if it will be liked in Poland, but I like it. And then the converters. This is a delicate matter, as my Prime uses sigma-delta DACs, and I know what they are capable of, but in my heart there is a special place for the PCM1704 model – all players using it sounded at least exciting. So this is enough for an introduction, it is the sound, which is most important here. SOUND )
Bitofon reminds me of a razor. A very specialized thing, that, if we do not know how to handle, can bring more harm than good, but in “conscious” hands is more effective than any other way of shaving. Its character continues the sound school of the amplifiers to a large extent – strong and dynamic. On the other hand, we can suspect, that the player was designed using the Amplifikator G for the listening sessions (at least in one of the control setups). After listening to the Bitofon I am sure this was the case. The most important frequency range in the player is the midrange. In difference to tube amplifiers it is not about its lower and medium subrange, creating the characteristic “warmth” but its whole range. The dynamics of this range, the ability to show differences in pace, dynamics and power – with one word the energy of the midrange is above average. For me an indication of such playing is the way my amplifier Leben CS-300 cooperates with the speakers Dobermann from Harpia Acoustics after connecting a new sound source. Those are quite difficult loudspeakers to drive, that have the highest current consumption, or at least the most audible one, in terms of distortion, not in the bass range but in the midrange. Connecting a player, that has strong or lurid upper midrange it will be heard as such. In reality the energy in that range is not big, because the compression is significant. It is different if the amount of information increases dramatically as does the dynamics – then, with high volume levels, the midrange starts to wheeze slightly. That was the case with the Bitofon. When Magda Kalmár sung, from the disc with Vivaldi music Laudate Pueri (Hungaroton Classic, HCD 11632, CD), then instantly one could hear that there is something going on in the midrange, something that is not there with most other players. Curious, but probably not accidental (I think that nothing is accidental, but we just are not able to pick-up the relationships or we do not understand them), but the parallel tested Nagra CDC player behaved similarly: the same charismatic character of the vocals, clarity in the upper frequency ranges and powerful dynamics. And it is not about pounding bass, this is not the frequency range for this, but something more sublime, something that cannot be defined that clearly, because it is usually not there in the sound. And it was heard even stronger with the disc Ros on Brodway from First Impression Music (Decca/FIM, LIM XR24 017, XRCD24), where blinding dynamics is recorded. Here one could hear the limitations of the Leben on the midrange and treble, audible in this system. And only the change to the Luxman system with the M-800A power amplifier, or even better to the EVO 222/402 by Krell (both systems in November) showed what this all is about – energy and unlimited dynamics. This gave open and full vocals. With electronic music, like Anja Garbarek Briefly Shaking (Virgin/EMI Music Norway, 8608022, CCD) repeated this - incredibly seldom heard reverb of the bass in the upper ranges of the spectrum were clear here, ideally enhancing the bass fundaments. This is something we could describe as “kick”, something that sometimes can be heard from professional stage equipment. But it is not an universal player, and it must be handled carefully. The mentioned dynamics and ability to show every tone in pace, dynamics and timbre can make some of the discs will sound worse than usual. Let us take the mentioned disc from Anja for example: the disc was issued with copy protection, that works in a way disturbing the pick-up circuitry, that it cannot read the disc properly, and what is heard as harshness and brightness of the treble, some confusion there. Amplifikator showed this stronger than usual, without restraint. This was the case with every disc of that type. With regular Compact Discs (if on the disc or the enclosure the logo is missing, then we deal probably with a CCD and not a CD) everything was OK., because even with a very strong in the treble disc from Coltrane Coltrane. (DeLuxe Edition) (Impulse/Universal, 589 567-2, 2 x CD), although the cymbals were strong as they should be, then it was not that unpleasant luridness and squeakiness like with Garbarek. I cannot do anything about this. Some change is brought by choice of a different digital filter. The converters often have such capabilities, but companies do not use it often, setting one of the filters – “sharp” or “slow” in a fixed setting. The first one is a classic symmetrical filter with “ringing” before and after the pulse, characterized by a very good filtering of reflections, meaning a sharp cut just outside the frequency band. The second one is characterized by the lack of ringing before the signal, with much softer slopes, is worse in filtering the distortion but allows to keep phase integrity. In case of the Amplifikator we can choose between them, and that during CD playback, so we can decide what suits us best. For me the slow filter was the clear winner. Although the treble was not as resolved as in the sharp setting, there is less of it, but also some “glassy” shine disappears from the upper midrange, everything becomes more vivid, and the vocals are more credible. Interestingly in the slow setting the bass is better. In general not very worked out, in the sharp setting it is quite short, and I find it lacking at times. In the optimal setting it is better, although it is not completely even – if the attack is strong, like from the Garbarek disc, then it sounds in a filled, deep way. But if the playing is more subtle, especially in the mid regions, like the contrabass from the disc The Route of Chet Baker i Art Pepper (Pacific Jazz/Capitol/EMI, 92931, SBM CD), then the attack and contour is somewhat lacking. The upper and lower bass are stronger, what makes the device play a bit too much to the front and lacking vividness in some systems. But this device is worth the fight, as the timbre of the midrange is phenomenal. Together with the way of presentation of the sound stage it reminds me of good class A amplifiers, with many harmonics, some kind of “foundation” for the basic tone, something that makes the sound rich. The attack is strong, but has also depth. The treble is slightly laid back, but the strong upper midrange deviates our attention from that. The happenings on the first plane are strong, and the second plane is shown in an equally clear, impressive way. And only further planes are compressed and even with so spaciously recorded discs as the Ros… not much from the depth can be heard. The resolution of the player is also not among the best. Similar to the Nagra the effect of “being there” is built mostly by gradating the dynamics, and not by precise drawing. So much about the sound. The handling of the device is quite user friendly, and the ability to choose the filter – a splendid idea. The only problem is the display. I was not to depict it, as it is to be replaced by a better one in the retail version, but now, even looking directly on it the contrast is much too low. A medium lit room and two meters distance are enough to make it completely unreadable. DESCRIPTION )
The player BitoFon of the company Amplifikator is built as solid as the amplifiers of that company. The chassis is made from thick steel plates, reinforced by even thicker aluminum. This sandwich structure is also present in the device's front panel, that has a look typical for the device line. In the place where there are knobs in the amplifier we have four buttons here – also not labeled. You can learn to use them quite quickly, but in the beginning some training is required. The solution is to use the remote controller – not very nice looking, almost identical to the one Ancient Audio is supplying with its devices. As it has buttons for input selection and volume control, I assume it can be used for controlling the Amplifikator amplifier. The drawer is placed in the middle – quite deep – and below it a red display. As it is a test version, it has a narrow readout angle, and is to be replaced in the retail version. Anyway, it is a low-noise customized display. On the back plate the looks are also professional, as besides the analog outputs XLR and RCA we have also digital outputs – coaxial RCA and AES/EBU. All sockets were made by Neutrik, hence the not typical but very solid RCA sockets, used only by a few absolutely top manufacturers. There is also an IEC socket. The device is positioned on very nice feet from aluminum and rubber. The insides are beautiful In the middle the Philips drive VAM120 is visible, seated on a special aluminum frame, that on its turn is supported by long aluminum feet. I have seen a similar solution earlier, in players from Xindak, but those were an exception, as this is a costly solution, and larger companies cannot afford such an extravaganza. To the left the power supply is visible – based on two toroidal transformers – separately for the controller and drive and separately for the analog section, with many secondary windings. Above them the PCB with the rectifiers and stabilizers is mounted – there are more of them than in most amplifiers. One took care even of such details as a anti-RF filter of the 2Pi type on the mains. To the right of the drive the servo PCB and audio circuits were placed. The control program is written especially for Amplifikator and loaded into an Atmel processor. The audio part is a very good digital filter DF1704 from Burr-Brown working together with two nice looking D/A converters PCM1704 from the same company. Behind those transformer enclosures are visible, the transformers are a part of the I/V conversion and the output stage. The latter is based on FET transistors. The whole circuit has a balanced (symmetric) topology. The used resistors are all of the metalized kind, precise with a low ppm. The capacitors are polypropylenes from WIMA, and the output is keyed with relays. The signal is lead to the outputs by means of short unshielded cables. Similar cables route the digital signals from the drive to the digital outputs – here the path is very short. The only thing I would add is the dampening of the steel plates with bitumen. However I might be nitpicking, as the device is really superb.
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