Free Lunch/Monkey/DRD inspired 2A3

[orionas]

here's Johnny....

Hello
They know have spent eleven years but would like to ask for the type of capacitor 50mF between anode and cathode in 2A3 (polypropylene is ok)

 

[jazbo8]

That's 50 uF not mF, motor-run cap might be a good choice.

 

[Palustris]

I use the Wima DC Link MKP type capacitor. Two 30uF should do fine. The only issue is that they are bulky.

 

[Ryssen]

About the hum,I use a Rod Coleman filament pcb,and there`s no hum on a monkey with C3g and 6B4G.

 

[soulmerchant]

Hello
They know have spent eleven years but would like to ask for the type of capacitor 50mF between anode and cathode in 2A3 (polypropylene is ok)

Calculate the value based on the impedance at cathode and desired low frequency cut-off. You might find that 45uF is fine.. DC Link is an excellent choice too.

 

[TonyTecson]

echo'd here....no noticible hum and ac heaters on 2A3

yes, there is no real need to use dc heaters on a 2A3 from my experience...

 

[Mickeystan]

lt_texan, the 417a should have a grid leak resistor added at the front end of the amplifier. An input coupling capacitor could be added too if you have any concerns about the source having any DC component to its output.

Mickeystan

 

[lt_texan]

lt_texan, the 417a should have a grid leak resistor added at the front end of the amplifier. An input coupling capacitor could be added too if you have any concerns about the source having any DC component to its output.

Mickeystan

I've got a 1meg grid leak resister not in the schematic. Thanks.