Octavia clone help

Started by blwnbwtie, February 02, 2013, 01:05:15 AM

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blwnbwtie

Hi guys,

1. I just finished building a TOCT pedal from General Guitar Gadgets
2. here is the link to the pedal i built http://www.generalguitargadgets.com/projects/22-octave/128-tycobrahe-octavia
3. PCB came with the kit so the layout is the same
4. i ordered the kit from them with all of the parts so every part value is true to the build
i am using the kit with the second foot switch to turn octave on and off
5. it is a negative ground circuit as intended for the kit
6. the fuzz portion off the pedal works fine, but the octave feature is not working

battery voltage = 9.5
+ voltage at board = 9.32
- voltage at board = 0

Q1
C= 2.984
B= 3.65
E= 4.36

Q2
C= 9.52
B= 2.982
E= 2.412

Q3
C= 5.05
B= 2.411
E= 1.750

D1
A= .6mV
K= 8.65

D2
A= .4mV
K= 8.1

I see that my voltage values at the transistors are all off.  I am pretty new to building pedals and help would be great.

Thanks

Jazznoise

You seem to have DC on both sides of your transformer. Essentialy both sides of those diodes should essentialy be at ground until a signal comes through at which point the voltage is the signal voltage minus 0.3v. The diodes are both wired facing out from the transformer, not in opposing directions - right?

Get the DMM and check that there's no shorts around your primary or secondary on the transformer. Check your resistances around Q1, I've a feeling the DC level in mine was abit higher. That said, if you get the octave effect working and it sounds good, go with it.

Using a 10K instead of the 1K pot for the Intensity allows you to do cleaner octave sounds and more ringmod type tones. You also get a more noticable octave and suboctave at v. low gains, making you sound more synth than guitar!
Expressway To Yr Null

blwnbwtie

I am getting pretty much nothing at the transformer.  It is about .4-.6 mV at each terminal on both sides.  The diodes are oriented correctly.

PRR

There should not be 8V on the diode cathodes.

Re-re-check your wiring and solder-bridges around pads L, V3 and the one next to it, and the Oct/Dist switch.

Note which way the switch lugs go-- on a 9-lug switch it is very easy to get the switch turned 90 degrees and get all-wrong action.
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blwnbwtie

Got it figured out, had a few bad solder joints.  Its working now.  Thanks for all the help.