newbie question

[sdorer]

Friends,
I am a relative newbie at this thing. I've been reading a lot which only continues to assure me how much I have to learn. I built an amp, a champ circuit froma junle mono tube amp I bought on ebay. It sounds good, rocking even. The problem is this extraneous noise, you tap on the chassis it make a loud static noise. Yout turn the pots on the guitar it makes a loud staticy noise. The noise comes from the speaker regardless of the setting on the volume. The amp is played in this video http://www.youtube.com/watch?v=aJ9CByQYF88
I made the guitar too. It was a lot of fun. Anyway any insight into this would be appreciated. Thanks for your time and patience with a new guy. PS I bought Merlin's book and that really reassures me I better get it straight with my beginner electronics book first.

[David Root]

I think you probably have some DC where it shouldn't be, and/or bad solder joint(s) or incorrect wiring. That causes static when you turn a pot. Since it's on the guitar pots, if it is DC then it's coming from the amplifier into the guitar.

It could also be a bad tube, I would check that first. Pull the preamp tube and replace it with a different one, ideally one that you know is good.

Also post a pic of the underside of the chassis so we can look at the wiring/components.

[Tinkerer]

I had a similar problem with a JCM800 (2204) that I built. It was my first build and I had much to learn. The advice given to me was to chopstick (yep, a chopstick from a Chinese take away joint) the board and all components on it to try and find the culprit. Mine turned out to be a resistor that was very badly soldered.

Tinkerer