Do you have a good schematic for a push-pull amplifier using type 50 tubes? I have four of them, and test strong.
If you don't a "good " schematic I am sure there must be plenty of US citizens who renovate 1920,s tube radios who would pay handsomely for them.
There is no consensus as to what constitutes a good schematic.. And without specifications to judge by. I can only Cite the Big Lebowski in that :"well that's just like your opinion man"
I have a couple off the shelf board designs that could get you started, free no strings attached either way. So i cannot give you support for anything.
V4lve lover's free gerbers thread. Theres a Phase splitter with 6N1P/6N2P
UniversalHV REV2.0 is a good universal board for power supplies.
Theres the Phase splitter that can.. Well split the phase
And to top it all off. The 1.5A regulators are excelent, if i may say so myself. More in those here: DHT heater supply design
Cheers.
V4lve.
I have a couple off the shelf board designs that could get you started, free no strings attached either way. So i cannot give you support for anything.
V4lve lover's free gerbers thread. Theres a Phase splitter with 6N1P/6N2P
UniversalHV REV2.0 is a good universal board for power supplies.
Theres the Phase splitter that can.. Well split the phase
And to top it all off. The 1.5A regulators are excelent, if i may say so myself. More in those here: DHT heater supply design
Cheers.
V4lve.
Keep in mind that if you go through the trouble of building something that uses the 50's, eventually they will wear out and you could be left with a brick for an amp if you can't find replacements.
Norman Crowhurst documented a trasnformer coupled 45 PP amp in an old book. That might be a place to start. @egellings makes a good point. Maybe try 45's and save the 50's. They are darn near priceless. Regards, Bill
Sser2… I think one could get away with C coupling, in this 'modern era' where pretty high value C and VC and 'tough as nails' electrolytics abound. They simply didn't have those “back in the old days”.
None-the-less, if y'all go to PocNet to find the 50.PDF file, you will also note that the expected voltage swing on the grid is rather enormous by today's standards. Valves became a whole lot more sensitive with pentode designs, and with the advent of coated cathode filaments.
So… to actually get some audio output from a set of 50's, you would need to drive them at well over ±100 VP-to-P or thereabouts.
If your amplifier front-en is up to that, well … its almost an output - ready design to start with! Also note the recommendation of 2,000 or 1,800 Ω plate transformer impedance. Its not too bad… √(1800 Ω ÷ 8 Ω) = 15 to 1 primary-to-secondary transformation.
What's that… if it were toroid power trafo, a 250 VA unit, 240 VAC primary, and a 16 VAC secondary?
About right.
⋅-⋅-⋅ Just saying, ⋅-⋅-⋅
⋅-=≡ GoatGuy ✓ ≡=-⋅
None-the-less, if y'all go to PocNet to find the 50.PDF file, you will also note that the expected voltage swing on the grid is rather enormous by today's standards. Valves became a whole lot more sensitive with pentode designs, and with the advent of coated cathode filaments.
So… to actually get some audio output from a set of 50's, you would need to drive them at well over ±100 VP-to-P or thereabouts.
If your amplifier front-en is up to that, well … its almost an output - ready design to start with! Also note the recommendation of 2,000 or 1,800 Ω plate transformer impedance. Its not too bad… √(1800 Ω ÷ 8 Ω) = 15 to 1 primary-to-secondary transformation.
What's that… if it were toroid power trafo, a 250 VA unit, 240 VAC primary, and a 16 VAC secondary?
About right.
⋅-⋅-⋅ Just saying, ⋅-⋅-⋅
⋅-=≡ GoatGuy ✓ ≡=-⋅
