So, I built a ring modulator pedal and it currently runs on two 9V batteries but they die out pretty quickly which obviously isn't ideal for jamming. I was wondering how to switch from the two battery connectors to an 18V ac adapter.
Find a Wall-Wart that puts out REGULATED DC 18V +-1V @ >100mA. Do not use one that is labeled AC. Not all DC adapters are created equal; some are half-wave rectified with no filter capacitor, some are full-wave rectified with no filter capacitor, some have a filter capacitor. The safest thing is to find one that says REGULATED on it...
Are you talking about the coaxial connector like found on most wall-warts? You can always cut it off, use your DC voltmeter to figure which is the positive lead, and then wire direct into your circuit.
Many wall warts that are not regulated have a lot of ripple riding on the DC anyway and could easily introduce a lot of annoying hum into the audio. A regulated wall wart may work or you could use a regular wall wart and build a regulator circuit yourself, which isnt too hard to do these days if you can work with small electronic components and can solder.
Many wall warts that are not regulated have a lot of ripple riding on the DC anyway and could easily introduce a lot of annoying hum into the audio. A regulated wall wart may work or you could use a regular wall wart and build a regulator circuit yourself, which isnt too hard to do these days if you can work with small electronic components and can solder.
Yeah I have a voltage regulator schematic around here somewhere. I'll most likely just try the regulated wall-wart straight first though because there is only so much space in my pedal box : P. Thanks though!
Yeah I have a voltage regulator schematic around here somewhere. I'll most likely just try the regulated wall-wart straight first though because there is only so much space in my pedal box : P. Thanks though!
If you made it, I would think you would know how to power it. Why is it using so much power?
Does it need +9 and -9 supplys for opamps or 18 volts or just 9 volts? How are the batterys wired? Andy
If you made it, I would think you would know how to power it. Why is it using so much power?
Does it need +9 and -9 supplys for opamps or 18 volts or just 9 volts? How are the batterys wired? Andy
I built it from a kit so its my learning experience on the side. I'm not sure why its using so much power, I'm checking that out now. I'm using new batteries to see if it was just a fluke. Hmmm, after double checking I guess they are being used as +9 and -9 supplies so the wall-wart might not work.
If the 9V batteries are just joined + to - with no other connections to the circuit, then it's an 18v supply. If they are joined and connected to common elements, then it's a +-9V supply.
They are connected to each other and to a common ground lug that grounds the input jacks and pots if that helps. Assume they are connected in series.
..the positive side is connected to the board, the middle positive and negative connections are going to the ground solder lug terminal, and the negative is going to the board.
See chapter five of the EPFM book for battery power examples; pages 210-212 for dc adapter and single to dual supply examples. Below is a sketch of the way two nine-volts are wired for the dual-dc supplies.
Defenitly dual supply. Do you have the book for this kit? You can try and make an AC adapter but you will need a wallwart with a 18Volt AC output. I have seen + and - supplys as well. Andy