valvulator v-1

[JC@]

I have a problem with one of these. It draws about 350mA by it's own son it blows the little fuse. With all the transformer secondaries lifted it still draws the same current, so I guess it is a transformer problem, unless there is something in front of the transformer that is partially shorted.
Someone may have a schem and tell me if it is a bad transformer or something else.
Thank you

[Enzo]

A schematic won't tell you if the parts are bad. Make a death cord - a plain old AC mains cord like one snipped off an alarm clock or table radio with a couple alligator clips on the loose end. Take the extra step and get the rubber boots for the clips. This is a dangerous tool, but so many are. Exercise caution using it.

Now disconnect the primary wires for your power transformer from the circuitry. We will connect the 120VAC mains directly to the transformer primary. What we need to do is watch the current draw. You could clip in a fuse holder in series with one wire and stick a fuse in it and see if it blows. But what I would do is set my DMM to AC current and clip its leads in series with one wirefrom the tranny. Now plug the death cord into an outlet. Your transformer, if good, should draw almost no current. If it draws current sitting there with power applied and no secondary connections, then it is bad. I would ignore any brief moment of current at the moment powr is applied.

Go over to RG's Geofex site and check out his transformer tester project - very simple.

[Steve Conner]

Hey, we have those in Britland too, but we call them "suicide leads" rather than death cords.

[Enzo]

Well now I have hear suicide cord too.

[JC@]

Enzo that's basically what I am doing now, but as this device is just a little bigger than an effect pedal, everything is soldered in a small board, transformer and all. Only the secondaries are connected with wires. It has components under the transformer too, so I was trying to know if there are any components soldered before the thansformer, appart the fuse that could be making a short of some kind.

[Enzo]

Sure, there could bad capacitors across the primary or something, and if they short... SO you have to go under and look nad if nothing else, pull the tranny and test.