The Farfisa Power Supply
 
 






Well I didn't realise just how many requests I'd get for information on how to build a power supply for the Farfisa.
I guess the original power supply would either explode into a thousand pieces or some space alien has been down and collected them all up. Who knows except my Farfisa had no power supply either when I bought it.

 Things have now moved on, thanks to Robert of Combo Organ I now have the circuit diagram of the F/AR power supply and from that all is possible. Also I have produced a sketch of the wires coming from my Compact so you can work out which wires go where.
There seems to have two versions made, one for the US and one for Europe so obviously all this information given here refers to the Euro version, it shouldn't be too difficult to figure out what needs changing for the US version.
 
 

F/AR Circuit Diagram

Here is a small version of the circuit, you will need to get the full sized one for it to be useful. It is 133k worth so if you are interested click here
 
 

small circuit diagram
 
 

Use this inconjunction with my sketch below of where the wires coming from the organ connect...

plug sketch





You now have sufficient information on how to connect your organ to a 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).
I built the minimum power supply needed, the circuit of which is shown below.

farfisa power supply circuit diagram





The + or positive goes to the red wire (pin 6), the - goes to the black wire (pin 5). Notice that the negative rail of the supply isn't connected to earth. I did this on purpose for reasons of polarity as described above. I figure the equipment the organ connects to will tie the power supply down accordingly, plus it helps reduce hum loops.
As you can see the input to the transformer is 240VAC because that's what we have here in England, so don't forget to change the tapping to suit your countries electricity supply.

And that's it! If this is too daunting for you then print out this page and take it to a decent tech guy because they should be able to do it real easy.
 
 
 

A New Replacement


I have now designed and built a replacement for the F/AR unit, it also includes a pre-amp just like the real thing. I would like to build and sell these units over the internet however I am restricted by the various rules and regulations such as CE marking. To get this would cost me thousands of Euro/Pounds which I'd have to add to the unit, due to the low volumes involved it's not practical. Same too for the USA where UL approval is required. If anyone knows a way round this please let me know.