LA NOUVELLE REVUE DU SON <CHARISMA>
The Australian electronics METAXAS have very quickly been very successful among the very tiny circle of high end, very musical but still affordable components.
The CHARISMA is the smallest model of the MAS range of preamplifiers, before the MARQUIS (TEST IN no. 150) and the OPULENCE. Its quality of fabrication, its superb finishes and listening quality could make it the top level in concurrent productions. One is here very far from esoteric and doubtful reliability products promised to uncertain careers.
The CHARISMA is a two separate chassis with same finishes: polished non-magnetic inbox steel, the smallest chassis is the power supply, the biggest the preamp itself. The link between them is a screwing high quality mode. Thus, the micro signals that enter the preamp are protected against the transformer or high frequencies noises.
The power supply transformer is a toroidal huge one. It is followed by a filtering stage with four condensers (total 35ooMf/ 35 volts), and, in the main chassis, two 2200Mf/ 40 volts. Very low noise and very fast I.C do the regulation. On this particular ground, the Charisma is much more sophisticated than concurrent productions, even more expensive ones.The preamplifier is able to treat 3 high level inputs and one phono stage, MM and MC. For this MC input, a double range of switches allows the adjustment of the loading resistors with a very high precision, since one can choose between 69 positions from 10 ohms to 47Kohms. It is thus quite easy to find the best value for optimization, with a precision that overdoes some cartridge - maker's specifications. The phono stage has been treated with a very high carc to ensure a total stability of the circuit. This input stage is a pair of bipolar differential transistors; these transistors are selected and work in A Class. The performance of this stage is exceptional in terms of over modulation ability, slew rate (1000V/ms!) and low distortion.
As to the output stage, a very low noise zener diode is used as current stabiliser of the A Class output current. Let us note that the entire front panel is used as thermic dissipater. The RIAA equalisation is impressively precise: +/- 0.2dB between 20 Hertz and 20Khertz: It uses a FET followed by a very low noise Op amplifier. This eliminates the residual shift and is located in the circuit of the DC servo control loop. This allows to avoid any condenser on the signal path, with all the advantages, amongst which a huge transparency.
The circuit configuration reminds us the Sunsey Minimu. The response curve of the circuit in open loop gets very low in high frequencies but his lowering wished by the designer of the circuit, allows a small feedback in high frequencies.
Of course, this drop in treble is taken in account in the calculation of the time constants of the RIAA active equaliser, which are no longer here calculated starting from strictly right curves. Through that way of doing, one gets a very high stability and it is possible. Thus to keep the very high operation speed the circuit can give (over 10MHz).The output stage of the line inputs has the same topology, using an Op Amp. Optimised by a linear amplifier on all the frequencies range.
In order to get the slowest signal degradation, the balance adjustment is not located on the modulation path, but in the feedback circuit:
A 40-position attenuator, whose each track has a more than necessary precision for an audio use, does the volume adjustment.
The protection of the electronic has not been forgotten: two FETS on the output drive a relay that cuts modulation as soon as the DC is over 0.6Volts. Thus, the amplifiers are protected against any fatal over voltages.
The finishes and fabrication qualities of this preamplifier are above generally admitted rules in high end audio, and let us think of a very high reliabity.
The ground planes of the large circuit (double-sided epoxy) gives a very efficient shielding, all components are of highest quality: polystyrene condensers, 1-% metal film resistors, and ALPS potentiometers… No wiring on this circuit, all components are soldered on the PC board.
No switch is at last installed. This preamplifier must remain under voltage all the time, and this is a guarantee of finest sounding whenever one wants to listen to it.
Listening Tests:
The Charisma is a A Class preamplifier; it must be connected for at least 24 hours before giving its best. In order to define its personality, we have listened to it with many amplifiers of different origins.
What stuck us first of all was its impressive analysis power. Nothing remains in the shade, either qualities or failing of sources or associate components. You will answer us that this is the least one can ask from a high level audio component… but it is not so obvious! Through our experience, we know that good preamp are more rare than good amps, and it occurs that preamp + amp associations often get weak because of the preamplifier. So, let us tell you that the performance of the Charisma gets more value by this way. In all combinations we had, the MAS showed a lack of repetitive noticeable failings: such as amplifier kept its own physiologic sounding, some other a small restraint in forte restitution.
A funny anecdote: the Charisma allowed us, in addition with our usual tests to confirm that a power amplifier would not be tested in this magazine, its performance being too bad.
The METAXAS analyses the message with a fantastic precision. It is able to give a great deal of micro information that are not usually heard or are lowered, atmospheres. Reverberation are transcript with a rare quality, giving thus a unique relief to the reproduction. On the CD: William Scheller "Scheller en Solitaire" for instance the interpreter and his piano are surrounded by a natural sonic atmosphere, with no misty or restrained aspect. On another side, a dull sounding recording keeps its characteristics: ho heaviness, but with intensity of the attacks and a tension approaching reality.
The Instrument of the Bosendorfer piano on Stakkato record is a fantastic experience. The instrument is dynamic, its attacks are open, definite, without any phenomenon of compression or crimping. The interpretation is fluent, fluid and never shows any "electronic stress". The silences between the notes are light, airy without this feeling of imposed sound cutting.
The sound clarity of the MAS that could lead to an over definition with unaccepted associate elements, is marvellous when listening to orchestral masses: each instrumentalist is perfectly located in space, with a fine differentiation of tessitures, and without any effect of inter modulation.
The very sophisticated power supply is obviously the case of these results, i.e. precision of focalization, even with complex messages.
According to us the Charisma is a new step towards a true and available 'High Fidelity without compromise". Its price quality ratio, which is more than interesting, will without any doubt, be a shadow for over rated components, whose prices keep them out of range of a majority of audiophiles.
Must be absolutely listened to in best conditions.
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