What power does a Tube Driver Take?

[eanderso22193]

I've got an old Chandler Tube Driver pedal that has no power jack, but has a 9volt battery harness wired into it...I don't think thats kosher. What power requirements does the Chandler actually have? What's it come wired for? Thanks.

Eric

[Thomas P.]

Is it the 3 knob Tubedriver? Then it could be running at 9V.
Take a look at this schematic:
http://www.muzique.com/schem/tubedrvr.gif

[tonepoet]

The 3 knobber is the Tube Works Tube Driver, Chandler made only 4 knobbers. On the original transformer power supply, it is stated as '120v, 60 hz, 15w input, 24vac@6va output'. You're in luck, I had the same situation and called Chandler about this, who was happy to help. Someone else had posed the same question, and here's my answer from another post:

I recently ordered a pickguard from Chandler and thought that I would ask them about a power supply for my Tube Driver (I had it changed when I went to Europe, and when I came back to the States, realized that I had thrown out the original!!). Well, I suppose that they get a lot of questions about the Tube Drivers (go figure), because they were very comfortable telling me about the specs and referred me to Condor Electronics with a part number. I called Condor (408-745-7141) and gave them the part number requested. I was sent a PDF for the part specs. The part you need is http://www.buycondor.com/catalog/detailac.cfm?ID=270 It's a A-24VO-0A4-U12. Good luck!

[eanderso22193]

Upon further inspection, I think its actually the 3-knobber, by B.K. Butler or someone like that. Thses things can actually run on a 9Volt Battery?

Eric

[jrc4558]

Yes but the battery life will be short. A regulated adapter of 200-500mA is recommended. Center-negative i guess, however make shure first...

[Peter Snowberg]

12AX7s run on either 12 or 6 volts, but not 9. If you regulated a 9V down to 6 and take into account that a 12AX7 pulls 300mA at 6V while the 9V has a total of roughly 650mA hours available (rated to 0.8V per cell), and that the regulator is maybe 75% efficient (being very generous), and then look at a datasheet about capacity versus discharge rate, you quickly see that an alkaline 9V will last only a couple minutes at the very best.

This does not even take the current to make the plate voltage into account.

Here is a typical 9V alkaline datasheet:
http://data.energizer.com/datasheets/library/primary/alkaline/energizer/consumer_oem/522.pdf

A 9V will last a long time if you pull the power out slowly, but the life is almost zero if you try to pull half of it's rated capacity out all at once.

There used to be good batteries for tubes but they don't make them any more. They were BIG. I can't even find a picture of one now, but I remember the diameter being about 2.5 inches with a height of about 6 inches with screw terminals on the top. They were built for a power draw of 300mA so you would still need four of them. There were also varoius "A batteries" with higher voltages but much less current available. There were also "B batteries" which put out 22.5, 45, 67.5 or 90 volts at a few milliamps. I think you can still get those from some place.

Now the only ones you can get easily are tiny "transistor age" batteries and cells.

blabber blabber blabber...

Take care,
-Peter