[sdiy] sort of OT: 50L6 nonelectrocuting amp

[anthony]

So every once in a while somehow I manage to dig up MORE realyl cool 
electronics junk that I've scavanged over the last 20-some years and forgot 
about. The other day I found a tub that had an old Bakelite radio chassis 
and two octal tubes: a 50L6 and a 12SQ7GT. The other tubes were missing but 
I had an idea what they were supposed to be and didn't care that they were 
gone except for the 35GZwhatever rectifier, but after I figured out what I 
wanted to do I didn't care that that was gone either.

I read up on amps that used these tubes and every single person said that 
amps using 12SQ7's and 50L6's sound great. Well cool, then I'd make me an 
amp right on that cheesy little chassis. Since I wasn't using three of the 
tubes I would have room to put two small transformers to isolate it from the 
power line and a solid state rectifier is all I need for a small 
single-ended amp.

The trick is getting the filament voltage. If I had the 35 volt rectifier I 
could have used just the filament in series with the others and that'd have 
made the voltage about right. I do have a small panel mount Variac which 
would work, but small for a Variac isn't exactly tiny - even for my tiniest 
one. Is there a reason not to use a volatge divider here? I just ask because 
I don't think I've ever seen anyone do it, but then people designing gear 
using these tubes way back when just used the tubes in series and nowadays 
tubes all have low voltage filaments.

BUT the real reason I'm posting this is because I haven't really found any 
good schematics to use for this amp. I think if I could find a schematic for 
something like the All American Five or any of a bunch of other radios like 
these. Any clues tips or insight would be much appreciated.


aa