HIGH-END TUBE AMPLIFIERS
Our new High-End amplifier is a continuation of our concept of a pre-studio microphone amplifier, which has proved to be the best when working in studios in Estonia, Latvia and the USA. In the device, for the shortest signal passage, tube balanced cascades are used on transformers wound on cores of amorphous (nanocrystalline) material, without the use of capacitors and resistors in the signal circuit. To adjust the volume level, a transformer-attenuator is also wound on an amorphous core. Specialists' feedback on the device is the most positive.
The real High-End amplifier being created contains all of the above principles and solutions, and, as an addition, it uses some other non-standard solutions, and we hope it will be beneficial to distinguish our device from the classical approach to building tube Hi-End amplifiers.
The device uses interstage and output toroidal transformers wound on high-quality, sufficient cross-section, transformer steel of double annealing in inert gas using the original winding, which made it possible to obtain a range of amplified frequencies of 5Hz -100KHz (+/- 0.5 db)
The power transformer is also toroidal - on high-quality, double annealing steel with network windings 115 + 115 volts (normalized by inductance, resistance, coil length and winding configuration). The amplifier is designed to operate on a 115 or 230 volt network.
The use of toroidal transformers predetermined the design of this device. The amplifier consists of 3 laser-treated thin-walled pipes with a diameter of 140 mm for two channels of the amplifier, and a diameter of 160 mm for the power supply. Pipes make it easy enough to perform grinding, polishing work for high-quality electroplating or painting. Using a laser, it is very easy to change the design of the ventilation holes in the pipes or to change the design when using other transformers and lamps. Transformers, lamps are organically placed in the pipes, which ensures good shielding between the power supply and amplifier units. The lamps are located in the niches of the housing, which prevents accidental contact with the lamps. There is also a solution for installing safety nets. The order of placement of lamps and transformers in the amplifier unit allows you to organize the shortest signal path, which is one of the main conditions for obtaining high-quality sound. All supply voltages are also supplied to both channels of the amplifiers in the shortest way through the holes in the side connecting cuffs. In the power supply unit, high-voltage rectifier kenotrons 5Z4G, russian analog 5Ц8С with subsequent electronic filters and double stabilization separately for each lamp were used to organize high-voltage voltage. Lamp filaments are also powered by a constant stabilized voltage. For installation and connections we use normalized silver wires in Teflon insulation. A great convenience is the system of organizing the setting of lamp modes used in the amplifier, which allows the replacement of lamps without the involvement of a specialist.
Separately, the amplifier uses a high-quality phono stage circuit for listening to records. It is possible to connect headphones when the output stage is in ST-BY mode.
For this design, the output lamps 6L6, 6V6, russian analog 6П6С were selected, since they have a good musical signature. And there is a batch of lamps with a minimum variation in parameters in sufficient quantities. The construct allows you to use other lamps.
One of the main nodes is a balanced interstage, loaded on two paired soviet russian 6П6С or 6П6С-ДР with a very low internal resistance, which allows to obtain very good coordination and the highest linear characteristic. The amplifier is equipped with a high quality case with inner velvet upholstery.