ForthMonkey
Well-known member
I finished my Poorman's Pultec.It's working good but there is hum!And it's louder than signal!I did everything about grounding.Now i want to make list about what happening!
1.When i plug in it to AC,directly getting hum and really low level signal like crosstalk!But power switch is off!I checked everything and there is no leakage.How is it possible?Even there is no electricity on board!But if i connect LM317's heatsing to chassis,i can reduce all hum and signal.What?!
2.When i open power switch,sometimes signal coming slowly like fade in without hum and sometimes again coming slowly with hum.But after 10 seconds,hum comes back!
Here is my schema...I need your helps!
Thanks.
1.When i plug in it to AC,directly getting hum and really low level signal like crosstalk!But power switch is off!I checked everything and there is no leakage.How is it possible?Even there is no electricity on board!But if i connect LM317's heatsing to chassis,i can reduce all hum and signal.What?!
2.When i open power switch,sometimes signal coming slowly like fade in without hum and sometimes again coming slowly with hum.But after 10 seconds,hum comes back!
Here is my schema...I need your helps!
Thanks.