The best rectifier please

[kristoffereide]

Ok, so I'm building a pedalboard with integrated powersupply and I just now realized that I get AC from the transformer. So I have to make my own rectifier, but I couldn't find a good schem in my searches. Can anyone link me to a schem? And also: would putting another rectifier i series make the DC even smoother? Sorry I can't remember, but many years have passed since school...

[zyxwyvu]

Ok, so I'm building a pedalboard with integrated powersupply and I just now realized that I get AC from the transformer. So I have to make my own rectifier, but I couldn't find a good schem in my searches. Can anyone link me to a schem?

For the purposes of stompbox power supplies, just about any combination of 4 diodes arranged correctly (http://en.wikipedia.org/wiki/Diode_bridge) will work. Given the choice, I would use either 1N400{1-7}'s, or a single bridge rectifier (like these). Just make sure it can handle the voltages and power (almost any rectifier/diode will, depeding of course on your specific requirements). Don't forget the smoothing caps, and a regulator if you want one.

For an example, check these out:
http://www.generalguitargadgets.com/index.php?option=com_content&task=view&id=135&Itemid=26
http://tonepad.com/project.asp?id=59
http://www.geofex.com/article_folders/pedalbdpwr/pedalbd.htm

And also: would putting another rectifier i series make the DC even smoother? Sorry I can't remember, but many years have passed since school...

No, this won't help.

[kristoffereide]

thanks alot!

[brett]

Hi
for really good noise rejection, try a small resistor (e.g. 3.3 ohms) in line and then a large cap (e.g. 1000uF) to ground, forming a low-pass filter.
For low power pedals you can get away with a larger resistor (tens of ohms).  For high power (e.g. digital) pedals, you shouldn't go much higher than about 10 ohms.
cheers

[kristoffereide]

I usually use the 100R100uF combination for each of the pedaloutputs and it works perfectly. My thought was also to use an -09 and a -12 chip for each output, rendering it possible to choose either 9V or 12V depending on the pedal.