With the final darTZeel NHB-458, it sets a new standard: after nine years of constant research and continuous development, this amplifier, not only it owns all the qualities of the NHB-108, already acclaimed by the whole audiophile world, but it goes further in revealing a very special machine in every respect. Some key features -The output is still higher than that already showed off the prototype presented in Las Vegas in 2009, and that with further improvements and stronger power: 450 watts RMS into 8 ohms, 800 into 4 ohms and 1000 ohms to 2 , resulting in more than 500, 900 and above, with control of the security offered by security software, the dynamic reproduction of music signals (an additional increase of the actual power generated will also depend on the voltage of power supply, often above, in practice, the nominal value of 230 Volts). -All audio circuits already shares the philosophy that inspired the popular NHB-108: no connection, no switch, relay or similar component, the signal path (except a relay of high quality, inert gas, for the XLR input) and no negative feedback in the input stage as well as in the output, without compensation network, or other Zobel, and configured as a true open-loop stage (already in the NHB-108). -Compared to the latter, the new ending has been made to further simplify the signal path, which now contains only three discrete components (transistors), each polarity, instead of the six dell'NHB-108, for the benefit of speed, transparency and dynamic, with the same low, if not absent, distortion. -The main transformer is a toroidal 2KVA, with capacity to supply more dynamic 4KVA, auxiliary power is required for control circuits and the fluorescent display, is provided by a different transformer, positioned at an angle of 90 degrees than the main one, in order to eliminate any possible magnetic interference between analog and digital, the XLR input is actively balanced without the use of matching transformers for a significantly better response at the extremes of the spectrum, for the first time in the history of darTZeel, the fuse on the main is replaced by a thermal switch, easy to reactivate the touch of a button on the back panel, and is able to ensure a more effective electrical contact is essential in view of the peaks current reach in this final. -As for the control circuits and the fluorescent display, the NHB-458 renews the technical and technological achievements attained by the integrated amplifier CTH-8550, thanks to the display, the user is able to perform the "settings" of the important parameters (type of input-XLR, RCA, BNC-, -26/32 dB nominal gain of input-, through activation of the rear USB port, just like the CTH-8550, etc. ..). -The internal circuits of control occurring in real time the RMS power dissipated and the peak temperature increase and the average maximum, and this has allowed us to maintain continuous monitoring of four pairs of players out in parallel, despite the considerable power generated more than 800 watts with 4 ohms load, compared to the one used pair sull'NHB-108 whose power is equal to one fourth (200 watts into 4 ohms), these components are installed very close to each other and are "fueled" by a special copper trace hybrid called "Common Rail Star", which is credited with a maximum sound clarity. -Thanks to the full and constant control of every parameter, the internal software dell'NHB-458 is able to prevent every possible incident, simply by interrupting the main power before the speaker coils to warm dangerously, but in any case, no limitation is present in the audio circuits as such, any control function being managed from outside, so that the maximum peak current allowed is simply enormous. * * * Given its high level of performance, sophistication in signal processing and listening pleasure, the final mono derTZeel NHB-458 could not stay in a lavish if not "container". The front panel is often 30 mm (twice all'NHB-108) and rear, which incorporates the heat sink, is 85 mm. The processors are supported elastically in three directions, with a sprung mass of over 25 kg., Granted in frequency so as to absorb any mechanical hum and vibration between 40-70 Hz: a real challenge in terms of compactness and efficiency. The large support feet, made of aluminum, they weigh more than 1 kg. Additional points each and are available for those who prefer this kind of ground support. The glass side walls complement the fascinating finish dell'NHB-458 and reserve you the pleasure (and pride) to be able to see (and show) the inside. The assembly has the precision of a Swiss watch. The NHB-458 is, in effect, and in every small detail, an excellent product of superior engineering. Suffice it to say that the time required for processing one of the aluminum parts, with the extraordinary results you want from the manufacturer, amounts to more than 150 hours! Only the lucky owners of this remarkable end can really feel, to experience, understand and, above all, enjoy the time, the inexpressible emotions, wide with both hands sound performance of the NHB-458.
