MAMEWorld Forums - The Loony Bin - Re: Anyone play with Tube amps?

> Since the load on the motor is pretty doesn't vary much, and it's designed to run at
> a constant speed, you can expect it to draw fairly consistent current while
> operational, which should give fairly constant cathode heat. The current will be
> higher while accelerating, but this should only take a few seconds, during which time
> the tube will heat faster. Having the tube heater in series like that will also limit
> inrush current to the motor when it's switched on.
>
> In a tube that has separate heater and cathode elements, the heater supply doesn't
> have to be particularly stable. The temperature of the cathode won't change much for
> transients as it has significant thermal mass.
>
> With older tubes where the heating filament actually is the cathode, you need a
> regulated DC power supply or a battery to power the heaters - you can't use an AC
> heating supply or this will be coupled straight through to the output. But that's a
> different story.

Facinating, never really played with tubes. Intresting little world for sure. Thanks.