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previous: eric p Thinking about buying this classic ... -- 10/26/1998 1:19 PM View Thread

Re: old ADA Flanger hum

10/26/1998 2:26 PM
Mark HammerRe: old ADA Flanger hum
From the clues you provide, it sounds like the power supply.  
 
There is little that is magical about PS's. All they have to do is supply sufficient voltage, current, and regulation, and have their plugs oriented with the appropriate polarity. Since the flanger likely wants either 12 or 15vdc, you have a world of possibilities, in terms of commercially available supplies or easy-to-build kits or plans.  
 
If you have a meter available, measure the DC voltage at the plug, and then measure the AC voltage. If the filter caps are still good, you should get very little AC voltage (the hum is AC "ripple" superimposed onto the DC, because of insufficienct filtering; think of filtering as the treble control of your power supply). If you've got 1vAC on top of your 12vdc, then you've got a bum supply.  
 
Any other irregularities in the sound of the thing?

 
Replies:
eric p Re: old ADA Flanger- anything weird about these? -- 10/27/1998 6:48 PM