below is the schematic for the tube rectifiers, one tube for the positive 6volt rail and one tube for the negative 6 volt rail, remember that two rectifier tubes are supplying the input 4558 ic with +/-6 volts, these tubes supplies around 3~4mA current.....what do you think? too much hard work for a measly 80mW consumption!!!
~24 watts spent for a mere 80mW gain..... 
notice too that the negative rail is a half-wave rectifier whereas the positive rail is a full wave type...
Tony sobra inefficient naman kung 24W spent (mostly for the heaters) then 80mW lang nagagamit! Besides, a +/-6V supply rails for the opamps is a bit on the low side, it may swing it's output very closely to it's rails. Siguro it's better to change it to a fullwave silicon rect which would be better than a "mestiso" fullwave/halfwave psu? And increase the supply rails for the opamps while you're at it na din.
Lalamig pa yun tranny pag pinalitan mo ng ss rects...
sir tony, sir jojo tanung curious lang, would replacing the tube rectifiers with silicone types alter also the sound character since i think the tubes give something to it? or hindi? hehehe!
no Sir it will not alter the sq, but increasing the opamp rails will - but for the betterment of the gear.
nakupo... powering an opamp with a tube rectifier while saying that it will improve the sound character is like walking naked in a gay bar with a sign saying "Rape Me!" (no offense to homosexuals)...
