Help with A/DA Flanger 1970s Power source - (no built in power)

[Heading]

Hi!

I really need help with this. The power source was left at a venue and stolen. From my research it seems to require 18vDC, but after hours I'm still unsure if it requires positive or negative polarity going into it, or the barrel tip size needed from the power source (seems to be need more than 2.1mm). Please advise, I really appreciate it and don't want to damage a $500 50 year old pedal.

[DrGonz78]

The older pedals were 12v 200ma with tip positive. Apparently there is a 15v regulator version too.

This is from Analogman website:

“A/DA power adaptor The early A/DA pedals used a 12V DC power transformer, positive tip, about 200mA should be more than enough. Some mid year versions need more than 12V or they will hum, as they use a 15V regulator. Those will work with the EH 18V DC adaptor sold for the EH Holier Grail or POG.@

[Heading]

I just found this on the ADA archived site!
The Original A/DA Flanger and Final Phase of 1978 through 1979 used an AC adapter. The rating was 18 to 20VDC at a minimum of 50ma. The connector is a 2.5mm x 5.5mm barrel or coax power plug. The polarity of the center pin is positive (+) and the sleeve of the plug is minus (-). The original A/DA part number is 240005. [Please note that the standard for AC adapters has been negative center pin and positive sleeve for the last 25 years. These will not work on the early A/DA stomp boxes.]
Do I need 20vDC??

[DrGonz78]

I would probably get this one. Save buying used option for $11.99.

[Heading]

I would probably get this one. Save buying used option for $11.99.

I just ordered this one https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[Heading]

Does anyone know why ADA says 18 to 20vDC ?

[Helmholtz]

Does anyone know why ADA says 18 to 20vDC ?

If the unit has a built-in 15V regulator, (unregulated) DC supply voltage needs to be a few volts higher than 15V.

[The Dude]

I'll add. If you are unsure of polarity, use your meter and check continuity from DC jack pins to ground. Most commonly one of them is ground. It saves guessing.