Sunking, everything works great, but I have a squeal with gain on zero!

[Analog Design Audio]

Hi guyw and have a happy new year , i built one of this pedal for a friend  and i have a very unusual problem , the pedal woks great on my hiwatt ( i used TL072CN ) but when my friend try to play it on his amps ( a marshall and a mesaboogie) the pedal works great when in buffer mode but when engaged it has a very big hum and noise when he just open a bit of the volume .

have any of you experianced any similar prolem ?

thank you very much

[Ward]

Hi guyw and have a happy new year , i built one of this pedal for a friend  and i have a very unusual problem , the pedal woks great on my hiwatt ( i used TL072CN ) but when my friend try to play it on his amps ( a marshall and a mesaboogie) the pedal works great when in buffer mode but when engaged it has a very big hum and noise when he just open a bit of the volume .

have any of you experianced any similar prolem ?

thank you very much

Is your friend powering the pedal with a wart different to how you power it? Some warts can induce a hum from hell. Try it with a battery if you haven't already, if you have, then I'm out.