[sdiy] heater voltage: how much is too much?

[Tim Ressel]

The filament of a 6E5 magic eye tube would drop
another 6 volts...  ;-)

--tr

--- anthony <aankrom at bluemarble.net> wrote:

> For the heaters in my 50L6 amp I used a 50C5 in
> series with the 50L6GT and 
> the 12SQ7GT to get a more proper heater voltage of
> around 112 VAC. However 
> my wall voltage is 120 VAC. I was wondering if this
> difference would be too 
> much. My first thought was that it shouldn't be
> problematic at all and the 
> extra 8 volts is distributed over all of the tubes
> and since the tubes are 
> designed for slow turn-on series connections, they
> should be able to handle. 
> Or should I try to squeeze something like a 8Ohm,
> 10W resistor in series 
> with them? I thought using just the heater of the
> 50C5 was a nifty if 
> hackish trick to get the heater voltage right
> though. Especially since I do 
> not forsee wanting to use it for an amp anytime soon
> since most of the 
> accounts that I have read concerning amps made from
> 50C5's is that they just 
> don't make the magic that a 50L6 can. (Although I
> have read similar things 
> about 6AQ5A's, but that when connected in
> "triode-mode" they sound great...)
> 
> aa 
> 
> 
>