Octavius kit from pcb mania

Pablo · Post by **Pablo** » 12 May 2023, 19:18

Hello,
I m a beginner in diy kit pedal, and I ve try the octavius kit from pcb mania.

I have some problem like no sound when I activate the pedal.

First question, how should I put the diode 1n34a ?

the two lines on the side indicated on the circuit?

it seems polarized upside down?

and I have a doubt about the connection of my switch.

if not where to look?

Thanks for your help...

mauman · Post by **mauman** » 12 May 2023, 21:50

Welcome to the forum!

I've attached the version 1.1 build doc. For troubleshooting help, please post photos of your build.

The diodes D2 and D3 are installed with the anodes toward the transformer, and the cathodes toward Volume pot lug 3. On a PCB, the line shows the cathode end of a diode. Silicon diodes are marked the same, with a line at the cathode end. But some germanium diodes are marked with one or two lines on the anode end, not the cathode.

You can check the polarity of a diode with a volt-ohm meter (VOM.) Set it for resistance (ohms) and put one test lead on each end of the diode. If you get no reading, reverse the test leads. When you get a reading (5k to 15k ohms maybe), your positive lead is on the anode and your negative lead is on the cathode. If your VOM has a "diode test" mode, use the same process, except your reading will be the forward voltage of the diode (Vf) instead of ohms.

Pablo · Post by **Pablo** » 13 May 2023, 11:46

I, I ve already use the build doc for made it.

I ve desoved the two diodes and test them. They are ok and I ve solded them correctly.

Thé other point is the transfo, that maybe I ve put in bad way, but I ve put the P in front of the P wrote on the board....?

See the pedal.

It s realy strange the bypass is ok, but when I turn it on the led lights up but no sound comes out. not even a buzz...

Thanks a lot for your help....

mauman · Post by **mauman** » 13 May 2023, 22:48

If the LED lights up, then you have power and ground! Your soldering looks OK, but I would probably add a little solder to the potentiometer lugs.

Could you add a picture that shows your foot switch wiring? It's not quite visible in the last photo.

If the foot switch is correct, the the next step would be to use an audio probe to trace the signal from the input jack through the foot switch, into the PCB.

It's possible to damage germanium diodes by overheating them during soldering, but if that's happened the audio probe will tell you where the signal stops.

Pablo · Post by **Pablo** » 14 May 2023, 20:19

Thanks.
I ll try the audio probe....

Look at my switch.
I first used the circuit made for but as no sound came out, I had a doubt about the meaning. as I had broken it by desoldering it to change direction I tried this way which follows the diagram of the circuit made for.

Thanks a lot

mauman · Post by **mauman** » 14 May 2023, 23:49

If you will adjust your foot switch wiring to make it look like this, it should work. Also, you have two "GND" holes at the top edge of your PCB, one is wired to the input jack shield lug, and one to the output jack shield lug. The +9V hole and the other GND hole at the top of the PCB should be wired to your battery jack.

Pablo · Post by **Pablo** » 15 May 2023, 16:06

Yep
I ve just try this option.... nothing better...
Yes the ground are like you say.

Next way audio probe....

Thanks

Pablo · Post by **Pablo** » 23 May 2023, 16:08

Hi,

I ve made an audio probe and try to find something.

I lost the signal after the R3 on one way, I tested it and it s ok 675k....
On the other way I lost it on the C3.... I ve try to change C3 and C2 but nothing better.
Thé soldering are tested ok and no problem with legs in support of C3....

The signal is lot really disappear, when I push the amp I can ear it really slow....

What other way possible?

Thanks a lot....

Pablo · Post by **Pablo** » 23 May 2023, 16:21

mauman · Post by **mauman** » 23 May 2023, 21:03

I've highlighted the audio paths. If you don't have a signal at the collector of Q3, then check the soldering at R9, R10 and C8, and verify that Q3 is installed correctly (collector/base/emitter in the correct holes.)

Pablo · Post by **Pablo** » 24 May 2023, 12:47

Thanks.

I ve check the soldering and Q3 looks correctly instaled.

The signal is really small after the R8 and dont arrive at Q3 and C8... R8 look ok (47k).
I ve try To put a bridge directly from R8 to C8 and now the signal go to the Q3 and the transfo... and after de germanium diodes but not a t the volume. I ve put a bridge directly after the two diode at the volume.
Now the signal arrives at the output BUT really small....! And lot really beautifful....

Other problem, the pot fuzz seem To works backward.....

which part of the pcb is supposed to increase the signal?
because after each resistance it decreases a little....

I am testing with a recording, and when I try with the guitar (the signal must be too weak), I have to turn up the volume of the amp a lot to hear something, and it doesn't really look like a fuzz or an octave.....

so I'm making progress but I'm not on the right track...

Did I Will got it ??

phatt · Post by **phatt** » 24 May 2023, 21:57

Maybe check that Transformer, I can't see enough but it looks like the Tx has 6 leads and the back of the PCB shows all 6 soldered.
The center lead on the primary should be left open, (as per schematic) if it's grounded them you would loose a lot of volume.
Phil.

Pablo · Post by **Pablo** » 30 May 2023, 15:28

I ve try this, nothing better....!