Solid State Guitar Amp Forum | DIY Guitar Amplifiers
Solid State Amplifiers => Amplifier Discussion => Topic started by: tra on December 07, 2010, 10:50:28 AM
I'm showing my noob here, but what is the best way to wire up power for the power amp circuit plus a lower voltage "tap" (excuse my use of the word) for the preamp modules.
-Wire a 9v regulator in parallel with the power amp using the DC coming from the rectifier?
-Wire a 9v PSU in parallel with the rectifier using the AC coming out of the transformer?
-Wire a separate transformer in parallel to the other transformer using the AC from the inlet?
I apologize in advance if this is a dumb question, and your help is greatly appreciated.
(http://i235.photobucket.com/albums/ee228/therecordingart/poweramp.jpg)
It's easy and cheap to go *down* in voltage, so you can get, say, 9V for a preamp from any higher voltage, from +12 to +60V.
Your 24VAC transformer will give you around 32V rectified.
(http://www.kpsec.freeuk.com/images/zenerd.gif)
A 470 ohms 2W resistor and a 500mW 9V Zener will provide you with 9V, up to 50mA to feed a lot of preamps.
+Vs is your rectified +32V.
Definitely simpler/cheaper than building an entire separate power supplu for the preamp.
You should wire a 1000uF x16V (or more) electrolytic capacitor in parallel with the Zener.
Pay attention to its polarity.
Awesome! Thank you for the help!