All models are originals. The copies are not made.
The amplifiers use electric circuits of the same type as for example the Mark Levinson No.38 and volume regulators potentiometers ALPS.
The construction is made of profiles of the American firm Nielsen. The surface of these profiles is formed with gold, black or titanium cut frozen elox with an extra hardness and a resistance to a mechanical damage.
Used filter capacitors are of a very good quality (usually the Computer Grade) and their capacities are from 27,000 μF to 1,000,000 μF.
They are usually equipped with a fully automatic input switch which does not contain any unlinear or mechanical switches, analog multiplexers or relays. As a matter of fact it is a part of a professional mix board. It automatically choses as active the signal source which is plugged in. This solution was chosen because practically every first-rate signal source as a CD player, a tuner, a satellite receiver etc. is operated by remote control. Because of the inner construction of all first-rate signal sources, the output of an unplugged signal source is automatically either directly earthed with a contact or a relay (like more "better" CD and DVD players work) or connected with the earth through low impedance.