[Amps] The power of an oversized electrolytic capacitor / how much PS filter C is enough?

[Dr. David Kirkby]

On 05/10/12 12:19 PM, Leigh Turner wrote:

> We can note the amplifier in question here uses a 4-1000 tetrode, and that
> such tubes exhibit a plate current virtually independent of plate voltage,
> i.e. tetrodes are a constant current device. Such a characteristic would
> make it more immune to ripple and noise on the B+ plate supply.
>
> Leigh
> VK5KLT

More immune than what?

Whilst the input current will be fairly independent of voltage, the input power, 
and hence output power will change if the HT supply varies. That leads to a loss 
of linearity.


If you have the ability, then using a 3 phase transformer could be considered. 
Even without capacitors, the ripple is quite small, since unlike a single phase 
supply, the input voltage is never zero.

I do have a 3 phase supply to my house, but it's not tempting to build an amp 
with it, as it restricts severely where you can use it.



Dave