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9V Power Supply Amperage

Yoa01

Jun 18, 2012
214
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Jun 18, 2012
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Hi guys!

It's been a while since I posted here (mainly because I'm pretty sure I annoyed the lot of you to the point of ignoring me) and I've been doing various nifty synth projects on my own.

I've decided that, among other things, I want to build a Eurorack modular synthesizer (a small one) completely by hand. I have all the audio and most of the CV stuff figured out, along with sizes and racks. My only problem now is a powered bus board.

What I have is a series of modules that can run off of a 9V battery. Some of them require OpAmps, which need bipolar power supplies.

Here's my question: would it be better to create a +9V 0V -9V bipolar power supply or have just a normal 9V 0V power supply and put a special +4.5V 0V -4.5V bipolar power supply on the modules that need it?

I only ask because I'm worried about output voltages and volumes. Say, if I take the output of an oscillator, which has a +9V to 0V output, and plug that into a filter, which has the 4.5V bipolar power supply, would that overpower the circuit? There are various other combinations, but I'm sure you get the general idea.
 

bountyhunter

Mar 9, 2012
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Mar 9, 2012
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There are single supply op amps available. An Ac signal swinging 0 - 9V is the same size as one swinging -4.5 - 4.5
 

Yoa01

Jun 18, 2012
214
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Jun 18, 2012
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I know, I'm just trying to use what I already have. They act the same, though, right? I figured as much about the size. I assume the size is the same with DC signals as well?
 

BobK

Jan 5, 2010
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Unless you are using rail-to-rail amps,. your +-4.5V supply will only give you a swing of about +-2V which might be limiting. I would go with +-9V, or use only rail-to-rail opamps.

Bob
 

Yoa01

Jun 18, 2012
214
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Jun 18, 2012
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214
I'll have to look into these opamps. Thanks guys!
 
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