Hush approach for DC filament..

[petemoore]

  Should I start with an AC WW supply and FWR/Filter to DC.
  I read AC WW's dont' always put out the kind of AC which can then be easily worked to DC.
  I've heard the filaments run quiet on AC >? That has to be the case, my amps 12ax7s' and output tubes all connect to PT taps.
  Start with a DC WW supply and put a BFC on there [IIRC I tried this one once and the some medium ripples got through.
  7812 DC regulator say it's good for 1. amp of output w/heatsinking...but is it actually necessary ?
 
  I built a pre-amp last night, and it performed just as expected, knock knock of wood ! !
  I put an inexpensive tube in there which I pre-lit once, using 7.2vdc for the heaters, sounds like good amount of preampage to me, with included filament noise input.
  Todays lesson for me is on the Shushing up of the filament input.
  Quick and dirty is fine, there's no tap on the existing transformer for 6.3V or 12V supplies.

[Gus]

First I would try AC with the heater voltage raised by a DC voltage above the cathode voltage.  Make a resistor divider string from the B+ and raise the heaters.  Often this and twisted pair and good layout can make a low noise heater supply.  Making a DC heater supply for low noise is sometimes not as easy as it first looks.

[petemoore]

  ...
  Transformer / FWR / Filtercaps installed, providing 15.6vdc.
  Perhaps just a 7812 regulator will do the trick ?

[runmikeyrun]

I used a 7812 on my valvecaster and twincaster, works great as long as you heatsink it.  Philcap's special order only but the local rat shacks have them for $1.59.  The one at chapel hill mall and chapel hill plaza both have some, i called yesterday.

[Gus]

You need >3VDC more than the output voltage of the reg for good regulation.

What is the AC RMS unloaded voltage and current rating of the WW?

Use a heatsink

It might work better with the tube wired for 6.3VDC if you don't have enough voltage but have enough current.

[petemoore]

  Hey, thanks for the help guys !
  It can be nailed down now, I believe it stems directly from my inability to know when to have mistrust for my DMM's, sometimes they lie and I rely on them.
  You need >3VDC more than the output voltage of the reg for good regulation.
  Scrapped the transformer that I had, [and should have scrapped the DMM] now I have one says: 20VAC / 400ma. output, "Class 2 Power Supply". The DMM reads 20.3vac, seems sorta reasonably in the ballpark [I expected higher]...I need a dern new DMM at least now...
What is the AC RMS unloaded voltage and current rating of the WW?
  20.3Vac, 1800Ma.
    It might work better with the tube wired for 6.3VDC if you don't have enough voltage but have enough current.  Prehaps that's the easy solution, a 7806..
  I can't get the regulator to want to work yet with the "Class 2, 20vac" power supply.
  With the load the input of the Vreg is seeing 15.5VDC...output reads 0.0VDc, tube lights with other PS pushing 7.2v on pins 4and5 through pin 9.
  Power Supplying 20.3Vac into FWR, FWR output is 15.5VDC loaded, Vreg. output is 0...
  I need something new to pop up, I'm running out of things to re-retest, re-rewire and re-recheck check.

[petemoore]

  It is all clean and new on perfboard, wide wire spacings...
  Now I get output from the 7812, probably not 20Vdc worth like the stupid DMM says, this still doesn't light the tube..still doesn't light.
  I have the DC power input across the outside terminals, positive on the left to pin 1, legs pointing down, reading the front of the 7812.
  The heater element is across pin 3 [Gnd.] and pin 2 [output].
  The simplest things are so hard to figure out sometimes.
  It seems like I should be putting whatever the transformer output marked.
  The 7812 puts out 20v or 0 v or 2.3vDc so far, not 12v.
  I have the tube filament across the Gnd. and output pin. [3 and 2].
  I have 15.5vdc appearing between the input and Gnd.
  I'm getting 2. some volts between the output and Gnd.
  Heat sink gets warm.
  It has to be my wiring with the 7812...numerous tries with various input supplies renders unusable output voltages.
  Pin 1 to V+.
  Pin 3 to Gnd.
  Pin 2 is output.
  DC input across pins 1 and 3.
  output taken from pins 3 and 2.
  I can't figure out what I'm missing here.
  3 is Gnd. but I have the whole thing floating, I think the Reg. should be putting out a voltage potential of 12v.
  But no...

[Jered]

  Pete, send me your address in a PM and I'll send you a new meter. I've got a spare or two,...or three...

[puretube]

Check your PINOUT !!!

[petemoore]

  Can't find the Data Sheet from that link.
  The package says
  pin 1 is input
  pin 2 is output
  pin 3 is ground
  ? ? ?

[petemoore]

  Silly regulator fine print ! ! Need the mag-glass to find out that 123 is actually 132. Seems it'd be easy enough to rearrange the Gnd. Input and Output prints, but Nooooo
   Haft go buy more regulators, I love miswiring then wiring them so much.
  HAd it all wired up and heat sank, nice sounding preamp a good bit noisier than I remember it being when I had the DC WW @7.2v working the 6.3v tube heater method.
   Regulators fritz anyway for some reason, not heat, nothing changed that was out in the open [everything is out in the open],  must have been the output and Gnd. connections being inverted.