foxx tone machine no octave

[Vitrolin]

hey  i builded a foxx tone macine i works but theres no octave, so no fun there.
transistors are 2n3904 and diodes are 1n4148 i double checked orientation on actave diodes

any thoughts out there?

[Mark Hammer]

Check your wiring, and check the transistor orientation.  Note as well that, as good as it is, you won't really hear much octaving below the 5th fret.

[Vitrolin]

i get fuzz but no octave on any fret at all
anything but the octave works
there is a short silence when i activete the octave and then everything is back to normal

[Derringer]

did you use any specific layout or schematic to build this ?

and, like Mark said, check your transistor orientation
diode orientation
check all your component values
check the octave switch wiring

[Vitrolin]

i used the ggg schematic and ive got signal trogh it with fuzz but no octave

[Vitrolin]

and the switch is not the problem, i hard wired it and still doesnt produce octave

[R.G.]

The answer to

"My XXXXX is not YYYYYing. Any idea what could be wrong?"

is always the same two items.

1. With no more information than that, *anything at all in the universe could be wrong*.
and
2. Read and follow "Debugging: What to do when it doesn't work".

[Mark Hammer]

Well tell us what it DOES do.

Is it louder than the bypass signal?
Is there distortion when you increase the gain?
Does the tone control work?

[Vitrolin]

hey im back being a bit busy lately
what it does i does a fuzz sound, it goes from silent to clean to fuzz with the turn of the sustain pot, when activating the octave switch there is a moment of silence (very short) then back to normal but no ocktave, i thought at a moment it could be a faulty switch but even when using clamps to connect/disconect D1 its exactly the same.
i did some measurements:
       NORMAL                          OCTAVE 
Q1: C=3,76 B=1,22 E=0,55   C=3,81 B=1,23 E=0,56
Q2: C=3,76 B=3,76 E=3,09   C=3,81 B=3,34 E=3,13
Q3: C=7,37 B=0,80 E=0,17   C=7,37 B=0,80 E=0,17
Q4: C=7,90 B=0,79 E=0,03   C=7,90 B=0,79 E=0,03

i hope this can give some one an idea want wrong, thanks

[liquids]

Blindly - you are using the wrong diodes, and I'd suspect you have them backwards.   It's easy to make a mistake around the rectifying diodes. But really, there is no true best place to start, except wherever you choose to begin, and continue throughout repeatedly until you find the error(s).  You will learn a lot from doing so.   Assume everything is wrong unless proven otherwise with your meter etc...continue until you find what does not match the schematic/etc.

Another quick (satisfying) idea would be to breadboard the circuit and compare side by side (voltages, audio, etc), get it working properly, and compare your build to your bread boarded build.  That would probably far more informative about what may be wrong than anyone's posted advice (including mine).

[Vitrolin]

ok my project is on a breadboard i always start on a bredboard since its anoying desoldering things due to orientation or other errors.
orientation is very much checked on diodes (as i said in original post) and transistors, and i have rebuildt it several times before posting here.

[Derringer]

what kind of diodes?

did you try flipping the diodes just to see if it still sounded the same?

[Badman]

wow! I'm having the exact same problem with mine TM. Did you fix yours by any chance?

[Hides-His-Eyes]

Vitro's Q2 looks fried to me unless it's supposed to be doing something really weird in this circuit.

[Vitrolin]

wow! I'm having the exact same problem with mine TM. Did you fix yours by any chance?

no i have not fixed it do you have any voltage measurements, i must admit ive put it on the shelf sore a wihle but im interested if there could be shedded some light on the problem
what where your transistors

[liquids]

Another shot in the dark, but I messed with one the other day and got similar issues because I forgot what would be R9 and R10 on this schematic:

http://www.generalguitargadgets.com/diagrams/ftmsc.gif?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a

[glops]

hey im back being a bit busy lately
what it does i does a fuzz sound, it goes from silent to clean to fuzz with the turn of the sustain pot, when activating the octave switch there is a moment of silence (very short) then back to normal but no ocktave, i thought at a moment it could be a faulty switch but even when using clamps to connect/disconect D1 its exactly the same.
i did some measurements:
       NORMAL                          OCTAVE 
Q1: C=3,76 B=1,22 E=0,55   C=3,81 B=1,23 E=0,56
Q2: C=3,76 B=3,76 E=3,09   C=3,81 B=3,34 E=3,13
Q3: C=7,37 B=0,80 E=0,17   C=7,37 B=0,80 E=0,17
Q4: C=7,90 B=0,79 E=0,03   C=7,90 B=0,79 E=0,03

i hope this can give some one an idea want wrong, thanks

I just built one and I have been doing some tweaking and I have one on a bread board.  From your posted voltages, your Q2 is what's
way off.  The other voltages looked about right.

[Vitrolin]

hey im back being a bit busy lately
what it does i does a fuzz sound, it goes from silent to clean to fuzz with the turn of the sustain pot, when activating the octave switch there is a moment of silence (very short) then back to normal but no ocktave, i thought at a moment it could be a faulty switch but even when using clamps to connect/disconect D1 its exactly the same.
i did some measurements:
       NORMAL                          OCTAVE 
Q1: C=3,76 B=1,22 E=0,55   C=3,81 B=1,23 E=0,56
Q2: C=3,76 B=3,76 E=3,09   C=3,81 B=3,34 E=3,13
Q3: C=7,37 B=0,80 E=0,17   C=7,37 B=0,80 E=0,17
Q4: C=7,90 B=0,79 E=0,03   C=7,90 B=0,79 E=0,03

i hope this can give some one an idea want wrong, thanks

I just built one and I have been doing some tweaking and I have one on a bread board.  From your posted voltages, your Q2 is what's
way off.  The other voltages looked about right.

ok thanks, i must admit that in a moment of frustration i took it apart and buildt a RMoktavia, it worked from test one, now i am making some changes, so it probably will stop working soon...