Rectifier tubes ??

[user 137017]

Just working on a small tube amp about 10 watts. I normaly just use silicon diods in the rectifer stage. I fancy trying tubes this time ez80 and ez81 are both in my parts stock. Looking at data sheets and old schematics some mention chokes being required while others say series anode resistors are required. Both the input and output transformers will both be on the generous side tabout 50va. Can anybody give some general advice please ( The power supply will not be running at high voltages perhapse only 200-0-200)

 

[Tubetec]

Tube rectifiers have a max reservoir capacitance , dont exceed this value ,

The choke isnt really a requirement , but a PI filter should get you lower noise ,
A smaller choke in the screen grid supply of the output tubes definately gives a bit more dynamic punch on the peaks , and generally results in a more pleasing distortion than RC filters in that position .

Making provision for the rectifier heater supply is the other concern ,
its possible to run some tube rectifiers off the same 6.3v ac supply as the rest of the tubes , but generally tube rectifiers run best with an elevated ground heater supply of their own , ie a seperate dedicated winding on the mains transformer .

Series resistance at the rectifier anodes you dont often see in amps , its seems to me correct transformer selection removes the need for series resistance ,
CJ might have something further to add here .

 

[user 137017]

Tube rectifiers have a max reservoir capacitance , dont exceed this value ,

The choke isnt really a requirement , but a PI filter should get you lower noise ,
A smaller choke in the screen grid supply of the output tubes definately gives a bit more dynamic punch on the peaks , and generally results in a more pleasing distortion than RC filters in that position .

Making provision for the rectifier heater supply is the other concern ,
its possible to run some tube rectifiers off the same 6.3v ac supply as the rest of the tubes , but generally tube rectifiers run best with an elevated ground heater supply of their own , ie a seperate dedicated winding on the mains transformer .

Series resistance at the rectifier anodes you dont often see in amps , its seems to me correct transformer selection removes the need for series resistance ,
CJ might have something further to add here .

Thanks mate. Thats all helpful info