Fulltone TTE hum

[klooon]

Unfortunately, no solution found. I reached out to the Dutch company that imported the unit in the past, and apparently they are not able to contact Fulltone...

[klooon]

Finally, after not being happy with the amp at all, I rechecked everything. It couldn't be that the amp should sound this "dark", and yes bingo....

[klooon]

Thanks. I did the resistance measurements and in bypass mode (power on and off) the resistance was 0 Ohm.
Yes, with power on it makes no differences...

[klooon]

I checked several things:

• Power chord disconnected:
  • True Bypass - no hum
  • "Effect On" - no sound

• Power chord connected:
  • True Bypass - very

...

[klooon]

Unfortunately, there is no schematic available. I searched on Fulltone's web page but there is now way of contacting them, unless you're a dealer.
...

[klooon]

Anybody? Some clues would be welcome! Thx....

[klooon]

I have a Fulltone tube delay unit and it hums badly. The strange thing is that is also hums in the True Bypass mode. Any clues what might cause this? ...

[klooon]

Thanks so much for your help and patience!...

[klooon]

I resoldered the grid wire, but also 80% of all other connections. The 22uF from point "1" to "2" was actually giving a tiny bit less...

[klooon]

Thanks. I redid the 'original' wiring. Strange thing is that there is more hum than I had a few days ago... Volume down gave 55dB and volume up all the way...

[klooon]

Unfortunately, the cold side of the 1k5 is not hum free. I thought yesterday, that it was for a moment. But up to now I could not reproduce it. So all it...

[klooon]

Then, if I understand you correctly, I put the screened wire (the one with the inner to 100R attached to the Grid) and the other end, both inner and shield...

[klooon]

I have replaced the tube socket and resoldered everything. The heater wires are now on the chassis and not up in the air. Everything is connected except the...

[klooon]

Thanks for the explanation. Good to know that "this" is normal.
Your second comment. It seems that there is no path with a 1M or so to ground,...

[klooon]

I did the check and it's only noisy when V1 comes in again. When leaving grid bare (no connection with any wire), there is a huge hum... I then I put a small...

[klooon]

Thanks! First time I tried to connect the screened side to the ground end of the 1k5 and it was dead quiet. Then I started moving around the screened wire...

[klooon]

I swapped them around, but no change. Also in the Netherlands, you can plug it either way (180deg), so swapping L and N. I swapped it with the plug and also...

[klooon]

Thanks. I will go more in detail through the layout and amp!...

[klooon]

Yes, volume "1" is zero volume. No it's more a humming noise. Higher frequency buzz is also there at higher volume settings and changes with moving...

[klooon]

Thanks for your help!


I did this and it does not change. The hums is just as much.

I tried this. The low frequency hum...

[klooon]

I am still not happy. I moved around the wires again and it still gives too much hum to my taste.




Yes. Very clearly. Volume...