It began trying to experiance the sound of single ended ClassA sound. The solution is very non-standard. Two 6C33C tubes work in "normal" mode e.g. like anode power voltage stabilisers. Other two work as power amplifiers - one for each channel.

That's how it looks with "devils" 6C33C and E88CC by JJ electronics. Outer tubes work as anode power stabilizers. Only outer sider are heated (when they fail, we just change sides and use them for twice as long). It doesn't make sense to heat both sides because of relatively low anode current. The inner tubes are heated fully to reach better sound quality utilising very low output impedance of parallel connected tubes. Anode current is 200-250 mA. Voltage - 200 V. After power on, only 70% anode current flows. After half an hour the current rises up to 110%, the after an hour goes back to normal. Therefore 6C33C is an unstable triode.

Inside, you can see the only capacitors in the audio path - high quality AUDYNCAP. A large pile of power supply electrolytic capacitors, anode stabilizer's voltage regulators, power tube anode voltage regulators.

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