[quaddriver]

All good suggestions, great initiative. I have not found a schematic for this yet, so I am winging it decoding the PCB myself. It would appear that the pecking order for the tri voltage power supply (standard AMFM tube fare) is that the 50C5 sucks on the teat last, so I can derive the line currents by measuring the voltage drop across the 56ohm and the 750 ohm, but I fear that the cathode votage is going to be around 70+.

The LEDs like Vf at 3-3.2 (I tend to aim for 3) and the run current is 20-25ma with max at 50ma. Aiming low,a 70volts-3volts = 67 volts times say 20ma gives me a watt and a half resistor (yea, they make those...so 3W) and I need a 3.3K-ish - that might be doable, I think I saw a lot of O-O-R in the parts bin.

The reason I dont wanna do a 10 or 20:1 xformer is unlike the speaker transformer which sees ALL audio frequencies, this one will be 60hz only....AM radios just *love* to amplify this - I'd have to install chokes everywhere.

I do have a lot of neon bulbs hanging around, but I got these high intensity LEDs and droppers for a song from parts express. I have been doing some cool stuff in the vintage SS units (just got a scott LCD to light up nice - the owners threw it out because it was dark...)

As to the suggestion about the heater string, I think I am in fact 125ish here. I have 3 12's, a 14, a 17 and a 50 - 117 on the knoggin. that gives me 8v to futz with and I have a crapload of old mazda bulbs. Mebbe tomorrow I'll go picking around and take some readings...

i could always allow more volts and amps inside when I change the SE rect for Si...I add a minimum of 100ohm to the inrush limiter (generally 22ohm) to make up for the voltage drop inherent in being a SE rect.....