5AR4/GZ34/5U4/5Y3 SS conversion

Conversion using UF5407 800V 3Amp 2-Pin DO-2 Soft Recovery Ultrafast Plastic Rectifier Diodes in a standard octal plug with the cap off of a fabric conditioner bottle a perfect press fit to finish it off :D
https://cursorium.co.uk/images/ssr-1.jpeg
https://cursorium.co.uk/images/ssr-2.jpeg

chris_w_uk03-25-2021 5:56pm

noromance Details Discussions Posts This discussion Message User 10,041 posts 03-27-2021 at 12:32pm Copy Comment URL Report Comment Edit Delete By doing this you've increased the voltage and removed the soft start effectively hitting the tubes with higher HT than designed before they've heated up. This can harm the tubes.
chris_w_uk OP Details Discussions Posts This discussion Message User 52 posts 03-27-2021 at 02:47pm Copy Comment URL Report Comment Edit Delete I have a thermsistor in the circuit, in fact two in parallel to slow it up even more. The Russian military EL84s in there will stand 315V and more with no problem, I have another amp that's been running them at 350V with no problem. Some commercially available amps run them way above 300V.
noromance Details Discussions Posts This discussion Message User 10,041 posts 03-27-2021 at 07:46pm Copy Comment URL Report Comment Edit Delete You know what your doing! I meant in the circuit though rather than in what the tubes can handle.