Conversion of 3 channel colour organ to 4 channel

Thread Starter

Max12345

Joined Aug 27, 2013
63
Hi all

I am trying to convert a 3 channel colour organ into a 4 channel one. Please see the pic.
All I want to do is to split the existing midrange channel into 2, without affecting the low and high channels. I have added in another channel.
1. Could you please help with the RC values for this?
2. On low and midrange1 channel, I will be driving 4 Red and 4 Green leds each (total of 20mA). On the midrange2 channel, 6 Blue leds (total of 40mA) and on the high channel, 8 White leds (total of 80mA). Do I need to change the base resistors of the transistors? If so, to what? The supply voltage is 12v.
3. The audio input is "line level". Where do I find this? I would like to use the speaker outputs directlly. Do I need an attenuator circuit? Can you provide me with a schematic please?
Thank you for any help I may receive.
Max
 

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Thread Starter

Max12345

Joined Aug 27, 2013
63
Hi Bertus
Thanks for the response.
Regarding the time, when I went into the CP, I discovered that the time was already set correctly. I am in Cape Town, South Africa so it is GMT +2.
Should Mid1 be from 320Hz to 800 Hz, and mid2 from 800Hz to 2.4KHz?
How do I determine the values of the caps to achieve this?
Or should I just change Mid1's cap to 47nF and Mid2's cap to 10nF?
Do you know of a site or program which will allow me to see the effect of changing the caps to specific values to see whether they fit into the freq response curves?
Max
 
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