Double shot schematics!!

[stephanovitch]

Idealy your relay + LED supply should be like this:
http://www.neufgiga.com/index.php?m=c9ae77e8&a=7d397569&share=LNK9733473a074d2d761

You can adjust 1K resistors for more brightness (depending of your LEDs)
I have not draw switchs

[pjwhite]

I could not access stephanovich's schematic, but came up with a simple solution that should work:


I think your 78L05 would be hard-pressed to dissapate 1/2 watt for any long period of time, so I would recommend a LM7805T or LM440T-5.0 instead (in the TO-220 package).  To calculate the power dissapation on the regulator I took 7 volts (the voltage drop across the regulator (12v - 5v) and multiplied that by the typical current with the relays on (80ma).  7 * 0.08 = 0.56 watt.

The 220 ohm current limiting resistor for the LED may be changed to adjust the brightness.  The 1N4002 diode should be able to handle the relay kickback voltage with no problem.  A 1N4148 is probably not really robust enough for this, I choose the larger diode to be safe.

[dschwartz]

yes pjwhite, that´s what im going to use..i already ordered 7805 (1 Amp) and i´m gonna place it instead of the resistors..

thanks for the diode tip..i put 4148´s there, so i´ll change it..

[stephanovitch]

Sorry for the link.
try this:
http://www.neufgiga.com/index.php?m=c9ae77e8&a=7d397569&share=LNK3594473b35fbe6661

[dschwartz]

well thanks..is the same idea..

anyway i hope you like the circuit (there´s the pcb i made posted on this forum)

i have to add the resistors for the bypass caps to ground, cause they´ll probably POP loud when reconnected (changing to distortion mode)

[stephanovitch]

I have build a preamp project like this 2 years ago.
I'm still working on it, because I search differents sounds.
There are 4 channels with individual gain and master, but only 2 passive equalizers sections.

Congratulation for your work!!

[dellamorte]

has the schematic for the power supply been updated? im looking into building a firefly and was wondering if the same power section could be used?

[dschwartz]

yes, it has been updated..this is teh new version: