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Yes, maybe can't see as in shadow of the capacitor.

I actually tried just removing the IC1 chip to check pin 4 not bent or something and replaced it and then tried plugging in again and it worked both sides until I flicked the left toggle switch to test that. Could it be the toggle - as the solder there isn't filling the holes like the  footswitches.

As an aside, I thought I'd read somewhere that not flooding holes on switches was best as it can lead to a short in the switch, which is why I tried to add solder to just one side. Maybe I misunderstood?

thanks, Rich

Ah, ok - I think on every build so far I have a ground issue! Thanks for the advice on the DC jack grounding and the IC voltages. I'll take a look at the ground wires first and then at the IC1. Really helpful - thanks! I may be back with more queries!

Had to go find out how to check the voltages and understand that its usually just the IC's and transistors that you measure? So the three IC's read:

IC1 (side not working)
1. 16.62v, 2. 16.53v, 3. 15.44v, 4. 15.92v, 5. 15.29v, 6. 15.36v, 7. 16.55v, 8. 17.19v

IC2
1. 15.42v, 2. 15.44v, 3. 14.06v, 4. 0v, 5. 15.29v, 6. 15.31v, 7. 15.26v, 8. 17.19v

IC3
1. 9.26v, 2. 5.91v, 3. 0v 4. -2.97v, 5. -3.04v, 6. 4.44v, 7. 5.74v, 8. 9.26v

I'm guessing the 0v and negative V readings are part of the issue - but not sure if that's normal as IC3 is the voltage doubler chip in the circuit. Nice to learn about voltage readings! I'm none the wiser, but might help you identify something.

thanks, Rich

Hi,

Just finished (PCB Mania) Knight of Tone pedal and as usual with my builds, there's a problem! Only the right side of the pedal circuit works as designed. When I then press the left foot switch , the LED comes on the pedal no longer works (both LEDs still lit). Turning volume knob on left side does make a crackle/hiss noise, and there's a audible click/pop when you switch the mini toggle, but still no sound. If I turn both footswitches off, guitar signal goes to amp. I did test outside of the enclosure - it was a few weeks ago and from memory I'm sure all worked ok. Does this sound like a short-circuit somewhere? Another facebook forum suggested the footswtich lugs need filling completely, so can try that, but thought I'd query here, as the expert folk here solved my last two pedal problems! Right side sounds good as least! Any help or direction welcome.

thanks, Rich

Vintage Columbo...tv gold!

Great, thanks - that's a good practical plan I understand!

Cheers, Rich

...actually, to quote Columbo, just one more thing...

On the finished photo again, it shows the labels on the two DPDT switches are reversed, Overdrive/Boost/Distortion for left switch (side A on the pcb) and Distortion/Boost/Overdrive (side B on pcb) - is this standard/correct, with both switches flicked left (as in photo) you'd get overdrive one side and distortion on the other. Or this another modification they've done? Just thinking of my own labelling being correct and understanding the pcb better. The diodes below switches do mirror each other on the pcb, so I think makes sense?

Great, thanks for the clear answers mjg and WormBoy, about it being powered at 9v and the 18v is internal on the circuit. It's that photo with the switch that got me confused most I think and that as a newbie was not understanding in the instructions! Cheers, I don't want a smoking and melted pedal! 

Hi - ok thanks. Does that mean you'd power it with 18v or 9v and then that part of the circuit doubles it internally? The build docs does specify power as 20mA (9v). But just reading again I think it answers my query, it says:

Another mod included here is the internal Charge pump, that takes the 9v input and doubles it to 18v, giving this way much more headroom and clarity. This can be easily bypassed as it's explained on the graphic bellow. (Schematic I think they mean)

Thanks again!

Hi all,

I've started a PCB Mania Knight of Tone pedal build and the build instructions (to me at least) seem a bit fuzzy on the voltage doubler part of the circuit. I can only find one image of another build of v3 - surely other people have done it, as modelled on  Analogman King of Tone. The photo I've found has a toggle switch on the top back side, above the DC jack and is labelled 9/18v switch. In the build instructions, it says the TC1044 IC is 'in charge of voltage doubler section', but its not obvious if this is an extra modification (if you know how) or part of standard build - the BOM lists that IC3 as part of the standard version, so am assuming I populate the whole pcb. I'm happy to have as 9v, if that's standard, but just a bit confused as doesn't show anything on the drilling template either for a switch. PCB Mania facebook support wasn't much help, so thought I'd try here as friendly person helped me get two pedals up and running! Have included pic of pcb, schematic and wiring diagram. Any help welcome!

Thanks, Rich

I tested the LED with multimeter and got nothing so removed and put a new one in that I tested first and now LED working too! Thanks again - feels good to fix it! Learning by mistakes always useful! A king of tone type pedal next project, so probably be back for help!

Cheers, Rich

Just to update on last reply - switching the wires on the input jack worked! LED doesn't light, so not sure if blown but that's an easy swap for new one to see if it solves that problem. Thanks again for steering me in the right direction Bio77!

thanks, Rich

Ah...looking at the wiring diagram again and the input jack the black wire from the battery clip is going to the tip of jack and the green wire from the switch is going to the ring lug of the jack. I'm guessing this is the problem!? Thanks Bio77 - we'll see if this works!

Hi,

Thanks for your thoughts - good just to look at things again. I'll check the wiring again of the jacks, as I get no sound. There's a yellow wire connecting the two jacks and from the output jack lug there is also a brown wire going to middle 'G' on the PCB. I'm assuming this was ground. Another brown wire to centre post of switch and blue wire going to L-shaped lug of DC plug. Isn't that everything connected to ground?

Thanks Rich

Hi all,

Another newbie query about a General Guitar Gadgets ITS8 - tube screamer build that fails to scream at all. Have tried battery and 9v power, but still nothing. Visually I've gone through the wiring and all seems to connected to the right place. Can a single bad solder, (if that's what it might be make a pedal silent?). LED not lit or any sound from guitar to amp whether switched on/off. Is this an obvious thing? Even tried a different chip, as had couple spare, but still nothing - I put the socket in wrong way round I think, but assume that's just a useful indicator for the chip, so as long as that's correct to the pub, that's ok? It may or may not help, but have included photo's in case something obvious someone can see immediately. Any help or kind advice welcome!

Thanks, Rich

Yes...I have Reverb!

Just made those changes you suggested, adding the 4.7k resistor on the switch pcb and a ground wire between the two pcb's and LED is on (hadn't burnt out), and all controls and switches working - sounds really cool - alot of different sounds with the feedback and deep switch. Thanks so much for your help!