More significant to Alexei were the aforementioned 'tube' properties and associated musical advantages of Germanium. He explains the modern audio industry's lack of interest in these parts as being caused by the scarcity and high cost of Germanium transistors in the West whereas in Russia they are common and inexpensive; and by problems related to obtaining substantial output power. Germanium-based amps are inevitably rather expensive and manufactures are used to the fact that an expensive amp must be a high-power amp. Exceptions merely prove the rule. It's common knowledge that Germanium transistors' significant flaws compared to silicon equivalents are low current limits and approximately 50% lower operating temps. Alexei quipped that "the transistor is carried away to Germanium Valhalla as soon as its temperature reaches 80°C." Hence the difficulty to obtain what by high-end standards would be considered decent output power; and the high cost associated with each watt.





In hifi, Germanium gave way to more promising silicon parts about a half century ago. Production of Germanium parts closed down at that time and wasn't revived thereafter. Unlike vinyl, Germanium didn't experience its renaissance. Yet in the USSR, Germanium transistors continued to be manufactured until the beginning of the second Millennium. Hence their supply remains almost unlimited and cheap. To match pairs for the output stages of his amps, Alexei easily acquired 2'000 powerful 1T813 transistors. Four work per channel, two in each half of a push-pull class AB topology. The output cascodes with independent sub-cascode feeds, the phase inverter and driver stage all use Germanium parts. The 1T813 output stage in common collector mode and at 1A of current produces 50 watts into 4Ω. A twice as powerful version with a different circuit is already on the drawing board but considering the size and weight of the current unit, you already appreciate the price/power conundrum of the Germanium proposition.


The upper -3dB bandwidth is 200kHz, THD at half and full power is 0.03/0.1% respectively. Class A bias carries the first 18 watts and the schematic uses no global negative feedback. The circuit topology is true dual mono including the ground planes.

The 'G' in the serial number is for Germanium. The operating time in hours feature occupies a part of the rear panel.

Each channel's power supply runs off its own 360VA toroidal transformer. A bank of 80'000µF smoothing capacitors sits in each branch of the push-pull circuit to add up to 320'000µF in total. That level of reserves precludes the need for voltage regulation.


Bearing in mind the current and temperature limits of his Germanium parts, Alexei paid utmost attention to circuit stability. For this purpose the Black Knight uses passive and active means. Current and temperature are controlled by an Arduino microprocessor. 5kg/ea. heat sinks flank each cheek. The chassis measures a bulky 48 х 310 х 50.5cm and a solid 29kg. Through the plumage-like slits made from thick steel plate, heat fins are visible. During our test with dynamic music at high levels, these hit about 40-45°C.