ilovefuzz.com

nope, transistors are not backwards (just checked)

Bump! Nobody is helping me out?

do you have a breadboard? can you breadboard this exact circuit and see if you can reproduce the problem?

I do not, but I'm going to rewire the whole thing again with new fresh parts, and most likely socket things this time.

If i were you i would do it again without sockets. Focus on shorter wires and good connections. Sockets might make it more unpredictable. If you are worried about heat damaging a transistor, use a hotter soldering iron with good technique.

I had a big 'ol debugging procedure typed up for you to follow, and I decided to look at your board one last time before I posted it.

I looked at your board.

Then I looked at the layout.

Then I looked back at your board.

Then back to the layout.

And then I realized that you built your board upside-down.

On the layout, you are seeing through the board, and the tracks are on the bottom. When you are viewing the component side, the power wires should be on the top left, not bottom left.

I bet that has something to do with it.

Mike

Seems to me when the impedence of the (signal) source is low, it goes into oscillation.
Does it oscillate if you short the input ?
how about with/without long guitar lead ?

Mike wrote:And then I realized that you built your board upside-down.

is that a problem? as long as you do everything upside down consistently, no problem. you can mirror and rotate as much as you want but the only thing that really matters is if the transistors are in backwards. if this were an opamp muff for example, building upside down would be impossible. anyway good observation, I'm sure it is helpful.

if your transistors are in backwards, I suggest you throw them out. reverse BE junction can damage a transistor. they are pretty cheap to replace.