Power supplies choices?

FAQ
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Welcome!
Your observation that this would be a good test/bench supply is spot on I think. When building power for a rack of modules you’ll want something reliable and linear. There are many good DIY examples here that will satisfy those two criteria. Why re-invent the wheel. Some here have even posted their own power PCBs, (have a look in the search up top).
Get stuck in and keep us posted.

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Thanks for the quick reply! I have a few more questions regarding the linear power supply:

  • I have a 14VAC 0.8A transformer (±22V DC if using caps + 2x diodes), is this too much for the 7912 regulator?
  • How bad is it to use a non-center-tapped design with two half-bridge rectifiers? (2 diodes, 3x 4700uF caps for each rail)?
  • Am I able to connect two linear regulator modules from one transformer?
  • But then, I should not connect the ±12V and +5V rails of different power supplies, right?
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12 VAC is enough; 14 VAC is going to produce more heat. But assuming an adequate heat sink and ventilation holes if it’s inside a case I’d think it would be all right.

Half bridge designs are common. See the Frequency Central designs, MFOS design, etc. Ultimately whether it’s good enough depends on your needs.

Your third question: Not sure if you mean a positive and a negative regulator for a ±12 V supply, or two pairs for two ±12 V supplies. But either way, yes. For the first, again see the above mentioned designs, and for the second, see e.g. this.

Fourth question: Right. Grounds should be connected, not power rails.

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Thank you very much!

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Just out of interest, for people using 12V AC wallwarts…

How hot do your wallwarts get?

I was also wondering if anyone was on a smart meter or had a sense of how much electricity is consumed by a synth powered by a 12V AC wallwart.

I have a (bad?) habit of leaving them powered on through a work day so I can have a quick noodle between meetings…

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Warm, not too hot to touch. Typically they use a few watts.

I have mine plugged into power strips with switches.

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In the 90’s I had a bass and a sans-amp stashed by a bookcase in my day job office for ‘noodling’.

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