Heater like Tube Amplifier

Tube low frequency amplifier driven by 2A3 produces some heat and I feel too warm in my room in this beginning of Summer season. Though it has 6FQ7 and 6AQ8 as its initial stage tube, single stereo design, they also have heater.
The transformer does the same. It is convenient in Winter season but these days not so.
Because a small tip plays a part of the audio amplifier now, I'm going to construct some new circuitry. My working place situates the position that is relatively near from Nipponbashi Osaka, 20 minutes by train. So, a procurement of any Semiconductor, capacitor and resistor is done like nothing.
I'll do that till the end of this month.
My writing work is almost over, total amount of 203.2 kilobyte with Japanese letters of 100,000 in total.
It took me about 30 days to do that and the time passed like an arrow.