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tiny tripple bypass question

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6/13/2000 7:05 PM

tiny tripple bypass question

Hi,
a few weeks ago I finished the ks69 fuzz and was very hapy with it, so I decided to go and try to put in a status light.
I had all the parts needed for the Tripple Bypass (1N914, 3x2N3904, resistor and led) and put it togheter yesterday...eh..night :-)

:-)

It worked, sort of, when nothing was plugged in.
It worked perfectly, the led went on when the effect was on, and the led went off when the effect was off...but when I plugged a jack into the input, the led stayed on, constantly going even slightly brighter when the effect was off.

I think I know what the problem is, but I am clueless how to solve it. The problem is that the +9v is soldered to the ring of the input jack and the sleeve is grounded, when I plug something in, the +9v connects to ground...no that can't be right...I'm doing something wrong. Anyway the effect works perfectly and so does the led when nothing is connected...but it's a bit silly stomping boxes on and off which aren't connected isn't it ?
Or maybe the effect is wired wrong ?
Does anybody have any answer for this ? I've gone over the comon pitfalls page on Aron's page but couldn't find anything that might solve this.

Regards,
Peter.

6/13/2000 7:42 PM

Re: tiny triple bypass question

ok, so here's part two of my little mistery. The input jack had it's sleeve connected directly to the sleeve of the output jack (which would otherwise be connected through the box I guess) and another wire going from the input sleeve to ground (on the board). I than connected the triple bypass +9v to the input sleeve and everything worked as it should, only when I turn up my amp now, I get noise, because the ground is disconnected. And when I connect it again, either through reconnecting the wires or through the box, I'm back to square one.

I'm sure this is a stupid mistake I made.
Even a hint in the right direction would be great.

Peter.

6/13/2000 8:24 PM
aron	The sleeves of the jacks should be connected to each other AND to the ground of the circuit board. The ring of the input jack should be connected the battery (either to the negative or to the positive if it's a PNP type circuit). The triple bypass circuit should be connected like the millenium or all of these variations. Check out GEO for different diagrams showing the connections.

6/13/2000 9:02 PM

Thanks Aron for clearing that up, I suspected it should be that way, so my wiring is correct.

Sleeves are connected together and to ground and input ring is connected to +9v (this is a PNP circiut).

Now what I don't understand is that the millenium and triple bypass have one end going to ground, and the other to +9v...but when I plug my jack in, +9v IS connected to ground.
Could it be that these circuits are designed for negative to ground circuits such as the rat was and that I need to turn things around on my bypass board such as the facing of the diodes and led and transistors ? Or are these circuits suitable for both positive to ground AND negative to ground.
It is slowly starting to get clear to me, so tell me if I'm saying stupid things.

Peter.

6/13/2000 9:06 PM
peter	oops, never mind my previous reply, I think I basically answered my own question there, things should be reversed when using positive to ground circuits....sorry for my lazyness As soon as I have slept a little I'll go try it out... Thanks again, Peter.

6/13/2000 10:58 PM
Steve Daniels (Small Bear Electronics)	Re: tiny tripple bypass question The "69" pedal is positive ground. I can't find he Triple Bypass circuit on Orman's page anymore, but, as I recall, that was set up standard for the (much more common) negative ground. You have the right idea. Myself, I'd try the reversing on a breadboard and be sure it worked there before doing any soldering. Just cautious...

6/13/2000 11:32 PM
Pete	Peter, I did the same ting with the fuzz face, worked with a battery, everytime I plugged in a power supply, the circuit wouldn't work, but disconnect the ground and it worked. Finally I drew out how everything was connected and bam: +'ve getting shorted to -'ve. It's not so obvious. Reversing everything should work, also make sure that your power supply is isolated from the main ground Pete

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