Powering a Farfisa without the F/AR ?

[Vincent80]

Hi all, I'm new here and am hoping for a little advice. I recently aquired a Farfisa Compact Duo organ. I got a good deal on it and it appears to be in good condition but it did not come with its own power unit, the F/AR spring reverb box. I've been reading some great resources on Farfisa organs online (including here) and this seems to be a common problem with vintage Farfisas.

I can find information on how to accurately recreate an F/AR box, but thats far above my abilities with electronics. For now I'd simply like to power the organ on and output the audio to an amplifier.

My question is, can I simply buy an XLR cable and use it to plug the organ straight into the mains?

Many thanks
Vincent80

[52 Bill]

Welcome to the place Vincent80!

In a word the answer is no. The power supply for the organ contains a power transformer and circuitry to create the low voltage that is needed to run the organ. In addition, it also has the reverb circuit and the output tone controls.

It may be possible to rig up a power supply to the organ to test it out and see if it is working, but this would require some knowledge of the organs circuitry. As I recall, there are two different supplies in the power supply box.

EDIT:
I did some online research and just to get the organ working, it needs a single dc source in the range of 12-18 volts. There is a second 9 vac supply that is used for the light bulb in the volume pedal, but this is not needed to get the organ to work. So I guess that you could try and hook up a larger wall wart to it and see if it will power up.

[Vincent80]

52Bill, thanks for the advice. I still might need a little bit of help from a pro but thats a good starting point.

[oc disorder]

Sounds like a wall wart is a good starting point to see if it works
I suppose you've already seen these...?

Build your own Farfisa power supply by David Barraclough.
How to build your own Farfisa Compact Duo power supply

"Things to note are the power supply has a pre-amp so if you omit this the output signal will be a little low. Solution is to turn up the gain on the mixing desk (board)."


And on an Auzzie site some additional info
Transicord

"The Barraclough supply -This design is a simple unregulated single supply of around 11 volts. It may get you going, but at best it is an incomplete subsitute for the F/AR supply .....If you understand the limitations of this approach (discussed below) then there is a simpler option of using a wallwart or other suitable supply, and a resistor in series.

The supply must be DC, at least 12 volts, and capable of delivering at least 200-250mA. It doesn't need to be a regulated supply but it must have a suitable resistor between the supply and the instrument in the positive lead.

Apart from the power supplies the F/AR also contained some audio circuitry, a preamp to lift the incoming instrument 60mV pk level to 300mV (gain ~x6) to be sent “dry” to the output amp, and to the reverb springline driver. The springline is followed by a recovery amp which supplies the “wet” signal to the output amp for mixing, which also has a gain of about x6 for a signal level of 2 volts into the following passive tone and output volume controls. "