Vinylsavor recommends the 801 but you really have to filter tungsten cathodes or they will hum. It might work with higher impedance headphones. Consider the 45 which you can heat with a 2.5 center tap transformer and the center tap to the cathode resistor with a capacitor in parallel to the resistor for no feedback and lower output impedance.
It would be fun to see a youtube video of an 833-A or even a GM-100 driving headphones with the listener's head exploding like in that ridiculous movie Scanners where you could see if you look for it the difficulty the actors have keeping straight faces while filming it.
It would be fun to see a youtube video of an 833-A or even a GM-100 driving headphones with the listener's head exploding like in that ridiculous movie Scanners where you could see if you look for it the difficulty the actors have keeping straight faces while filming it.
i tought the 2a3 will be headphone endgame, but there is something extra in thorium and graphite to sound.............
on ebay once were cheap 801a´s ... did not bought them
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Those pictures are excelsior! For those of you who might like the build an 833A SET: The 833A Single Ended Triode Amplfier - YouTube They are not very difficult to build and if you already have a 2A3 or 45 SET or even a 300B which you like you can transformer couple it to the grid of the 833A.
Yes indeed, my first iteration of 833a (GU-48) was driven by a KT66 (as a triode) single ended amplifier and transformer coupled.
Currently I'm rebuilding the amps and will be driving the 833a grid with a solid state stage (similar to power drive) with a 112a front end transformer coupled.
It'll get finished one day.
As far as I can tell, I think I have solved any problems I encountered getting my 833A stereo to work. I really like the sound of it and I over-designed everything I used which has worked for three years. That is not to say I did not have to experiment with such things as parallel feed vs normal transformers for the 45 to drive the 833A grid and redesigning the power supply so the chokes would be on the negative side for safety and going with polypropylene filter capacitors instead of messing with electrolytic capacitors in series for the 1000 Volts I like on the tubes.
Does that mean the 833A is the one true faith against which everyone who takes a difference in an infidel? Of course not. But building the 833A is not as difficult as many people think.
Does that mean the 833A is the one true faith against which everyone who takes a difference in an infidel? Of course not. But building the 833A is not as difficult as many people think.
I have reported this GU48 amp quite recently
in this thread
https://www.diyaudio.com/forums/tub...rs-pmc-eb1i-speakers.html?highlight=VladimirK
in this thread
https://www.diyaudio.com/forums/tub...rs-pmc-eb1i-speakers.html?highlight=VladimirK