12ax7 heater[s] DC or AC?

[petemoore]

I've got one going on a 9VAC supply, but I have another, and I need a supply for that.
 Does DC or AC even matter? I looked at description/data sheet and it only specified voltage,.. not DC or AC...
 I know the Shaka works on AC for the heater, also DC...I just don't want to fry any tube heaters trying to figure it out.

[Peter Snowberg]

I hope that tube is wired for 12V heaters, if not, it's not going to last too long. I've seen a number of notes about running heaters at the proper voltage and they all say don't run low, but I think that's because the ratings go out the window and not because of damage to the tubes.

I like DC on heaters because the hum issue goes away that way.

The easiest thing to do is to use a regulator like a 7805 and put a couple of 1N4001s in the ground lead (pointing toward ground). Each diode you put in there will raise the output of the regulator by that forward voltage. Two diodes should give you something between 6.0 and 6.3 volts which is perfect. At 6.3 volts, the heaters want 300mA.

There's my 2 cents.

Take care,
-Peter

[The Tone God]

Tube filmants can use either DC or AC. As long as you give the heater the right voltage with the proper amperage you should be cool or hot as the case may be. Occasionally I float a 7805 using a couple of resistors to get exactly 6.3v DC. If your already using a 12v regulator with enough voltage on its input you could float it to get 12.6v.

Andrew

[petemoore]

I'll just have to see about all that you typed.
 I pretty much follow, by the time the tube fails I'll probly forget....that Me :? .
 Right now it seems to be running very well on the 9VAC adapter, at 10.86 VAC, using pins 4-5.
 with The second 'Shaka-OA' [tube part only] on the bench, and some PS wirings yet to go, I'll try these things you typed about , after I ch ch ch ch ch check it out!!! and see wh wh hw wh what's it all about!!!