If the schematic doesn't have a connection listed for the negative voltage (but has one for the positive), is the default connection for the negative just to connect it to ground?
Specifically, I'm looking at Jack's MiniTubes (gotta love all this free time while collecting unemployment). The +9v to 36v connection is clear, but there's no indication for the negative. I wired up the one I'm using now and get no sound and one of the transistor & caps started to get really hot and smelled like it might start burning. I'll double check my connections again, but may go back to the drawing board for a more compact layout.
TIA,
Buck
Do you have the link for the schematic? About the caps, check the voltage of your power supply and the voltage of the caps. The caps need a bigger voltage than power supply to work with no problems.
Since the MiniTubes is a Mu-amp based pedal, it uses a single-ended supply (positive and ground) so yes, the - side of things sits at ground level.
Remember, on a battery you have 9V to play with. If one point is +9V, it's ALWAYS related to ground which is *defined* as 0V. Therefor the - connection should be at ground level.
If you hook up more batteries instead of using a chargepump (4x 9V cells) hook them up in series, and connect the first one's - to ground, and the last one's + to V+.
The caps need to be rated AT LEAST 63V, preferably more. Also, check your tranny pinout.
This circuit works at lower voltages, so check it out with 9V or 18V first, so as not to fry anything when you've got a mistake.
hih
Marcos,
Sorry I don't have a link for the schem. This was downloaded from AMZ way back when, prior to the AMZ CD being the source for the schematics.
I'm running this one on a 24v DC adapter. I'll take it out of the case, remove the DPDT and try it at 9-18v and doublecheck everything. I figured the negative went to ground but wasn't 100% sure.
Thanks again,
Buck
Change all the caps for caps with voltage bigger than 30v. I think you burned your caps. Could you send me the schematic?
munkydiy@hotmail.com