Members kevorkazito Posted February 28, 2006 Members Share Posted February 28, 2006 I have an older Crybaby that required a 9V battery. Since removing the battery clip and hard-wiring a 9V power-supply (Boss transformer) the pedal emits I loud hum when I activate it. Someone told me that it has to do with grounding it. Does anyone know how I can remedy this? Background: The pedal makes the hum when activated only when my signal is overdriven or distored; there is no hum with a clean signal. My electronics expertise is that I'm a good solder'er I replaced the pot with a new one before I cut off the battery clip. There was no hum after the I replaced the pot and powered it with the 9v battery. Please Help Link to comment Share on other sites More sharing options...
Members andreas Posted February 28, 2006 Members Share Posted February 28, 2006 First off, it's my firm belief that a stock crybaby does not need adapter power - it only uses a minute amount of power, and a decent alkaline will last several years. I think mine went at least 4 years with the same battery... Wah circuits can be very sensitive to adapter hum (as you noticed ), so powering it with a battery can save you lots of headaches. But it can be done, and newer pedals work just fine from a Boss PSA supply. The problem here is that your pedal was never designed for adapter power, and therefore it doesn't have the extra filtering (on the power supply input) the newer ones have. So what you're hearing is power supply ripple (leftover artefacts from the AC voltage), which of course is then amplified greatly by the distortion. Find the point where the positive voltage enters the circuit board, and tie a capacitor from there to ground (usually, there will be a ground or battery negative connection right next to the positive input point). 47-100uF works fine, and make sure it is rated for 16 volts or more. Electrolytic caps are almost always polarized, so make sure you orient the negative side (usually indicated along the side of the cap) towards ground. That should help smooth out the ripple that causes the hum. /Andreas Link to comment Share on other sites More sharing options...
Members zinzin Posted February 28, 2006 Members Share Posted February 28, 2006 Originally posted by andreas First off, it's my firm belief that a stock crybaby does not need adapter power - it only uses a minute amount of power, and a decent alkaline will last several years. I think mine went at least 4 years with the same battery... Wah circuits can be very sensitive to adapter hum (as you noticed ), so powering it with a battery can save you lots of headaches. /Andreas is that the reason why vox does not make wahs with AC power supply option? Link to comment Share on other sites More sharing options...
Members andreas Posted February 28, 2006 Members Share Posted February 28, 2006 I don't know if that's the reason - the original was designed in a world where there were no adapter jacks on anything, so they probably just didn't bother to update it. The V848 has a DC input, though. But the fact is that you'd have to play *a lot* (several hours every day) for the battery situation in a regular Vox/Crybaby to become a hassle. If you play more normal amounts, and remember to unplug the cable from the input jack when you aren't playing, the battery should last a couple of years. /Andreas Link to comment Share on other sites More sharing options...
Members kevorkazito Posted March 1, 2006 Author Members Share Posted March 1, 2006 Andreas, thank you for your informed response! I'm going to perform that mod you suggested and post back here. As far as battery life, I go through those $9 batteries every couple of months. It isn't that I use the wah alot, on the contrary, I keep forgetting to unplug the 1/4" jack from it Thanks again. I'm going to learn more about electronics theory and have with your assistance Link to comment Share on other sites More sharing options...
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