Elekit TU-8900 - 300B/2A3 SE Power Amp Kit
Elekit TU-8900 - 300B/2A3 SE Power Amp Kit
Single ended triode
- As the name suggests this power amp from Elekit supports both the 300B and 2A3 tubes in a single-ended tube amp kit. The 300B with its rich
midrange and extended bass - and 2A3 with its delicate expression and gentle tone - offer a very special sonic experience in this new design. This is an amp with amazing sound quality, super low noise, and which can be used with a wide range of headphones.
- Whilst the 300B and 2A3 look similar their operating parameters are quite different. When the amp powers up it automatically detects the tubes installed and corrects the filament voltage and voltage of B-power. This is indicated by the colour of the volume knob surround LEDs.
- The headphone volume and impedance settings can be changed by simply moving the jumper location on the PCB. Ample space for larger coupling capacitors on the PCB is also provided.
- The power transformer has independent windings for the right and left channel to minimize the interference between channels as much as possible. The filament power uses the latest DC-DC converter with extremely low noise and high efficiency. Schottky barrier diodes and fast recovery diodes are used as rectifying diodes that reduce even the most negligible noise spikes. Listeners can enjoy music free from noise even when using a pair of high efficiency headphones. The main circuit of the power unit is unitised per channel as a module.
- Tube Friendly design: Warm-up time for directly-heated tubes and indirectly-heated tubes are different. In most designs, directly-heated tubes warm up faster than indirectly-heated tubes. So directly-heated tubes are often overloaded. With TU-8900, the voltage is gradually raised which reduces the level of overload to the directly-heated tubes.
Note re Tubes:
- Tubes are not included in standard kit supply. Customers may request tube supply at time of purchase. (Product image shown is promotional only).
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Lundahl LL2785C AM output transformers (note: replaces standard OPTs)
This upgrade for Elekit TU-8900 uses specifically designed Lundahl output transformers (OPT) featuring amorphous cores rather than pure iron and upgraded coupling capacitors with Mundorf top of the line oil impregnated silver/gold capacitors for a superb listening experience.
An amorphous core overcomes a feature of iron cores, that of magnetic saturation. The Lundahls replace the stock OPTs that would otherwise ship with the amp.
The quality of a tube amplifier’s OPTs is extremely important, especially so for single-ended amplifiers. Design is all important as an air gap in the transformer is needed to prevent transformer core saturation, which would cause audible distortion and other problems. Herein lies the challenge: having an air gap lowers the inductance, which compromises low-frequency response yet to increase the inductance requires adding more windings, which adversely affects the high-frequency response.
The silver/gold oil Mundorf capacitors is featured in this version of the TU-8900 due to its wonderful natural tone and exceptional micro dynamics. The high-purity silver and gold is used for the capacitor coating and the winding is impregnated with a special oil developed in an exhaustive series of experiments and listening tests.
Sweden's Lundahl is a specialist designer and manufacturer of high performance transformers.
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