TS808 frustrating debug

[Sidahmed]

Okay okaay guys, sorry for being a bit late, I had a lot of work to do !

So, after I followed what you all said, for the Hum sound in my amp I tested all of my ground points and they were all Ok, all of them. I guess the hum maybe comes from another thing.
I also swapped the 100nF cap by a 220nF in tone section, and yeaah it sounds better.

Now, here are my voltages

Power supply: 9.35V

D1 (1N914) : 4.62V (+)  4.58V (-)
D2 (1N4148) : 4.62V(-)  4.58V(+)

Both T1 and T2 are 2N3904.
T1: E: 3.26 V                                     T2: E: 3.23V
      B: 3.76 V                                          B: 3.72V
      C: 9.23V                                           C: 9.23V

IC:  TL072
1- 4.58V
2- 4.62V
3- 4.58V
4- 0V
5- 4.58V
6- 4.58V
7- 4.58V
8- 9.23v       

Thanks

[antonis]

Do you use a stereo Input jack (with sleeve and ring)..??
If yes, is Input plug plugged when you take measurements..??

Good spot, Antonis.

IMHO, it frequently equals to unsocket IC "non-working" pedals..
(especially for "advanced: builders..)

[patrick398]

Voltages all look spot on so i'm guessing the pedal is functioning as it should and you're getting hum from somewhere else. Do you get any hum with your guitar straight into the amp? Could be that it's already there and the gain from the tube screamer is just amplifying it.

[Sidahmed]

Idk, when i use the amp without the pedal I get no hum, but when I use it, there hum, it emphasize when i turn the gain up or the knobs to max

[EBK]

Could you post some pics of your board?

[Sidahmed]

Dont judge the board lol pretty messy and not clean, just testing the effect, I got the PCB ready to solder for it.  As i said, i tested for shorts or for ground with continuity setting, it is all ok from this side

[EBK]

Is that enclosure metal?  Hopefully, the answer is "yes."  Does the bushing of at least one of those jacks electrically contact the metal of the enclosure?  Essentially, I'm asking if your enclosure is providing any sort of shielding here.

[Sidahmed]

No, it is not metal, that's why I wired the jacks sleeve between them. It is plastic, I guess no shielding, what are the consequences?

[EBK]

No, it is not metal, that's why I wired the jacks sleeve between them. It is plastic, I guess no shielding, what are the consequences?

The consequences typically would be hum, possibly exactly what you are hearing. 
As a test, you could try covering the whole thing up with a tent made out of foil, with the foil touching one of the jack sleeves.  The hum might just disappear.

[Sidahmed]

Okay I'll try it ! Is aluminum foil will work? how can I actually cover it, do i have to stick all the foil?

[EBK]

Okay I'll try it ! Is aluminum foil will work? how can I actually cover it, do i have to stick all the foil?

This is just a quick check to see if the lack of shielding explains your humming.  Nothing fancy.  Aluminum foil is fine.  Doesn't matter how the foil looks (you can wrap the whole thing like a baked potato).  Just matters that it is grounded somewhere (touching the sleeve on at least one of the jacks is simplest). 

As far as more permanent shielding, you could either switch to a metal enclosure (my recommendation), or you could glue some foil to the inside of that plastic one.  Alternatively, you could wrap the circuit board in something non-conductive then cover that with foil (and running a wire to ground).

There are also conductive paints and shielding tape you could use, but those will cost the same or more than just buying a metal enclosure.

[Sidahmed]

Thank youuu, very useful information for the noob who I am, I will try with the foil and will tell you about the result. Btw, I do have aluminum enclosures, I just wanted to test the circuit on perf and then will build another one with the pcb I have, which will be my final effect. That was a beta one haha

[MrStab]

if you still hear the hum, when the pedal's off, and your amp's off, and you're in a field in the middle of nowhere, use the foil to make a hat