I plan on trying out a quad of EL156 Telefunken tubes In a Dynaco ST70 clone. Can anyone recommend any needed circuit mods that I might need?
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I have modified power supply to use 2 parallel 274b with extra capacitance. I'd like to sub 4 el 156 for 4 el34. The 156 has similar Specs to KT 88, my amp is built to accept kt88 . I can pull about 450 volts B+. The 156 cam hamdle 800 v.
It would be a waste of your EL156 tubes to use it in your Dynaco clone; the Dynaco can't provide the voltages and currents that the EL156 work best at. It would be similar if someone had a 45 triode amp and wanted to convert it to use 845 triodes. It would work but not optimally.
If you want to use your EL156 tubes in an amp, it would be better if you could provide it with higher voltages to the plates, like 650+ volts and something around 350 volts to the screens; ultra-linear isn't optimal for this tube.
But they're your tubes, I guess you can do what you wish with them. The Dynaco will not take advantage of what this tube can offer though...
I have an amp that runs a pair of EL156 tubes that has a power output of 100+ watts. Plate voltage is 750v and screen voltage is 360v to the EL156s.
By the way... The EL156 is more similar to a EL34 than a KT88. Think of the EL156 as an EL34 on steroids. ONE EL156 is roughly equal to two EL34s.
If you want to use your EL156 tubes in an amp, it would be better if you could provide it with higher voltages to the plates, like 650+ volts and something around 350 volts to the screens; ultra-linear isn't optimal for this tube.
But they're your tubes, I guess you can do what you wish with them. The Dynaco will not take advantage of what this tube can offer though...
I have an amp that runs a pair of EL156 tubes that has a power output of 100+ watts. Plate voltage is 750v and screen voltage is 360v to the EL156s.
By the way... The EL156 is more similar to a EL34 than a KT88. Think of the EL156 as an EL34 on steroids. ONE EL156 is roughly equal to two EL34s.
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I have made many mods already. I'm willing
To upgrade the transformers to get 600v B+. I have ditched the quad can cap and add high quality caps, dual chokes, have 2 eml 274b mesh plates in parallel. Can you recommend power and output trans that work in pp ultralnear? The chAssis is custom . An I use E80cc as drive er s and phase splitter' ? Any help would. E appreciated. I ha e a quad of now Telefunken 156 and want to do this
To upgrade the transformers to get 600v B+. I have ditched the quad can cap and add high quality caps, dual chokes, have 2 eml 274b mesh plates in parallel. Can you recommend power and output trans that work in pp ultralnear? The chAssis is custom . An I use E80cc as drive er s and phase splitter' ? Any help would. E appreciated. I ha e a quad of now Telefunken 156 and want to do this
Don't fall for that high voltage, high power, light idle current siren song.
The PA060 power trans is about up to running a single pair of EL156's.
cheers,
Douglas
The PA060 power trans is about up to running a single pair of EL156's.
cheers,
Douglas
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