Wish Klon Clone fuzz/distortion/crackle...

[Dgsaudio]

Hi all, first post here after performing a search. There have been several similar topics but none that seem to have resolved the issue.

Recently built the Wish Klon Clone. I have power and sound and overall it sounds great!

But... the pedal produces a electronic buzz or hiss or crackle when low notes are played with high output pickups. This happens not only with the pedal on (which i could live with as it is less noticeable), but also in bypass mode, so it is distracting and doesn't sound great. I've tried it with multiple amps, power supplies, cables, etc.

As the issue happens with the switch on and off, i think it could be caused by some of the parts shared by the buffered bypass and on setting, but dont know what those would be.

Photos attached.

Pin measurements below:

IC1

1: 4.54
2: 4.54
3: 1.08
4: 0
5: 4.42
6: 4.53
7: 4.53
8: 8.97

IC2

1: 4.52
2: 4.54
3: 4.48
4: -8.9
5: 4.48
6: 4.54
7: 4.55
8: 16.81

7660s

1: 8.96
2: 4.54
3: 0
4: -4.36
5: -8.88
6: 4.35
7: 3.7
8: 8.96

Ive reached my limit of electronics knowledge here! Ive re-soldered any suspect connections but to no avail. Any help or suggestions are appreciated!

[Kevin Mitchell]

Whats up with that fractured looking opamp?

[Dgsaudio]

Whats up with that fractured looking opamp?

Just surface scratches from the tweezers I used to pull it and put it back in when i was trying to diagnose.

[FSFX]

There are a load of really bad TL072 op amps being sold that suffer from noise and crackle when driven hard.
I don't know where you got your TL072s from but I would suggest replacing them with genuine TI ones from trusted places like Mouser or Farnell. 

[antonis]

Pin measurements below:

IC1

1: 4.54
2: 4.54
3: 1.08
4: 0
5: 4.42
6: 4.53
7: 4.53
8: 8.97

I would like a schematic for reference but, even without one, pin 3 (non-inverting input) doesn't feel so good..

[FSFX]

.

[Dgsaudio]

There are a load of really bad TL072 op amps being sold that suffer from noise and crackle when driven hard.
I don't know where you got your TL072s from but I would suggest replacing them with genuine TI ones from trusted places like Mouser or Farnell.

They just came with the kit. They have the TI logo on there, but of course they could be counterfeit.

[FSFX]

There are a load of really bad TL072 op amps being sold that suffer from noise and crackle when driven hard.
I don't know where you got your TL072s from but I would suggest replacing them with genuine TI ones from trusted places like Mouser or Farnell.

They just came with the kit. They have the TI logo on there, but of course they could be counterfeit.

Personally, I would not trust them. I have seen lots of reports of people getting TL072 devices from places like Tayda that turned out completely unusable.
I have had TL072s from some places that have tested Ok at low levels but get a bit of a kink in the waveform when driven with larger signals. The genuine TI TL072s do not do that.
I would not trust any TL072s that come from China, or at least you need to thoroughly test them to see how they behave with a large range of signal levels.

[antonis]

-

[FSFX]

.

[antonis]

-

[FSFX]

.

[FSFX]

-

[antonis]

-

[FSFX]

-

[FSFX]

-

[Dgsaudio]

That's exactly what I'd expect..
(maybe a bit lower but definately not lower than 3V, say..)

Anyway, why do you keep on about this trying to contradict everything I say whilst in fact the problem is a load of fake or inferior TL072 chips that exhibit the crackling sound that the OP originally reported.

Simple fact is that there are loads of bad TL072 chips being sold. This has been reported by many on the forums and in the Facebook groups.

I really appreciate the help from all parties and will order some new tl072s to see if that resolves the problem.

[antonis]

-

[FSFX]

-

[antonis]

-