Need some ITS8 pedal help

Started by Arson, February 13, 2012, 11:33:32 PM

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Arson

Hi all, I've currently stalled trying my first pedal build and would really appreciate some help, here's some base info on it:

-GGG ITS8/Ibanez TS808 clone
-(Schematic) http://www.generalguitargadgets.com/pdf/ggg_its8_sc.pdf?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a
-I followed the layout the best I could, and I've gone through and double checked everything about a half dozen times.
-As for the odd resistor thing going on in the top right of the included photo (R2), the resistor the kit came with was behaving oddly, so we (me and my brother) linked a 470k and a 47k, and it was acting the same as before. 
-It's a negative ground, I believe.
-When the switch off, clean signal goes through just fine, when on; nothing.

Batt V:   8.86
IC pin 1:   4.38
IC pin 2:   4.32
IC pin 3:   4.38
IC pin 4:   .2miliV
IC pin 5:   4.38
IC pin 6:   4.37
IC pin 7:   4.37
IC pin 8:   8.83

Q1:      E-3.22
      B-3.66
      C-8.83

Q2:      E-3.19
      B-3.63
      C-8.83


candletears7

Are those cuts through the traces?

iccaros

is your IC upside down or is the socket in wrong?

Arson

the socket is wrong, the ic chip is correct (unless i'm totally wrong.  :) )  there are two spots on the trace where the plastic has chipped off, but continuity test shows that its still intact, and nothing could have shorted on them.  i'll definitely cover them up before i install it, but i don't think thats the problem.

kevilay

which transistors are you using? I know the kit comes with option ones that do not have the same lead positioning.

Arson

2N4401.  I think the bill of materials says the 2SC1815 is the one with a different pin format.

Le québécois

There is a electrolitic capacitor in the top right who look like ''la tour de Pise'' :icon_lol: Make sure it do not touch and short the resistor below.
The voltage look good. Post your diode voltage also.
The switch wiring?


kevilay

I think seeing your switch wiring would help, Otherwise I think it would be a component issue of some sort.

Arson

yeah, its definitely not the cleanest soldering job.  the cap is definitely not shorting on the resistor. 

the diode voltages are:
D1:
   a:  4.21
   k:  4.44
D2:
   a:  4.44
   k:  4.20
D3:
   a:  4.43
   k:  4.36   
D4:
   a:  4.36
   k:  4.43
D5:
   a:  0
   k:  8.91

photo of the switch


the wiring is as follows from back to front
brown to board labeled "O" (output?)  ---  black to -led  ---  2nd brown to tip of input also jumpered to bottom right
orange to tip of output  ---  black to ground  ---  green to input
black jumped from top right  ---  second and third pins jumped together


Le québécois

The voltage look ok.
For the resistor R2 I used 470 k as for R12 for one of my TS build since no available 510k at that moment. I ear no difference so don't bother about that. But... what do you mean by the ''kit resistor was behaving oddly''?

Second, have you try the effect without all the switch and LED stuff? tip of input jack straight to Fx-input and output of fx to output jack. Don't forget the ground (ground of input jack to ground of output jack +Fx ground to the output jack ground).

Third: I'm not certain about this one but if the signal is passing in the clipping stage while switched to LED clipping, those should light up while you play (at least a little bit -- close the light in the room might help).

Other than that, I have no clue. You will need to check with a continuity tester each of the connection and listen for a ''bip'' when you expect connectivity.