Trying to restore and repair this 50 year old color organ. Worked awesome back in the day. Dont want to find another circuit.
Its missing some parts and circuits. Maybe some theory on how scrs fire off on sound input could help.

 

Maybe some theory on how scrs fire off on sound input could help.

There is no connection shown to the input signal. Is the input signal from a speaker?

The Rs and Cs likely form passive low pass, band pass, and high pass filters that trigger the gates of the SCRs. But I don't see how the SCRs can be turned off.

 

I believe this is your kit.
I could not find the component values

 

I believe this is your kit.
I could not find the component values

View attachment 371766

I saw the values in another diagram, this one should be roughly similar:
R1,R2 10k
R4 1.2k
C1 0.1uF
C2 0.15uF C3 0.8uF
C4 0.33uF

 

Any specs on the audio transformer?

 

p.s. Mine has individual pots for each channel

 

They say that almost any low-power transformer works, for example 230/24V.
The transformer is connected backwards, that is, the Audio Input is connected to the low voltage winding.