I've just completed an...huh... Express...huh...radio...

[Tubetwang]

I approched this Express build like a Micro-Surgeon.

I wanted to be an Allynmey kind a build...a work of art...a museum piece...I have never had an amp working right out the bat.

I checked my layout over and over, patiently and diligently...like a Buddist Monk... no cravings nor aversions...

Powered it up just now... hooked to my favorite strat...house emptied (fiance and twelve year old out for the day:lol: )...ready to work my best Greg Koch's rendition and ?

I get an out of tune radio sound...

Any tips from experience builders would be most welcome...

[dartanion]

Do you have a bottom plate to cover the chassis opening? If not, you will need something to shield the chassis. The other thing to try is a grid stopper on the V1a.

My Liverpool doesn't pick up radio, but it does have NFB related oscillation due to poor wire routing on my part.

[mhuss]

Based on my recent experiences, , you might want to try a small coil on the input instead of the traditional resistor, as the resistor (even 33k) makes it hum a bit more.

--mark

[Tubetwang]

All i get is radio sound through the speaker...no guitar sound...i went over my layout a thousand times and everything should be ok.

I know it's not the guitar nor the cable.

Went through all my books and web and nothing on troubleshooting radio sound only...

[skyboltone]

First try a better guitar cord if you don't already have one. Do you have shielded cable between the input jack and the grid of V1a? Do you have the grid stopper resistor soldered in between that shielded cable run and the grid pin of V1 socket? Did you ground the shielded cable at one end only? Do you have 1 megohm between the input pin and ground?

Dan

[mhuss]

By "radio sound" do you mean static/white noise (vs. an actual radio station?) Does it do this when no guitar cord is plugged in, or only with a cord?

Try removing V1 and see if the noise goes away. If not, try removing V2. This will help localize the problem.

--mark

[Tubetwang]

IT WORKS!!!!!!
IT WORKS!!!!!!

Thanks for the help guys...and moral support...the shielded wire from input to V1 was bad...I have a tendency to recuparate wires from old computer, tv and whatever i collect from roadside trash...

I though of maybe changing this wire cuz everything else was ok it seemed...whoa...i'm soooo happy...

Thanks again to all for the help in these crusial moments...my first Wreck is done...i think Ken would be proud of me and all of you guys...

[UR12]

Congrats Twang!!!!

[Tubetwang]

Thanks Dana!

I'm still floating!!

[philmanatee]

Awesome! Phil

[dartanion]

EXCELLENT!!!


Clips?

[drhulsey]

IT WORKS!!!!!!

DUDE

[doctord02]

pics?

[Tubetwang]

you guys don't want to hear me play ...beside, i have to eventually learn how to record and dowload clips...

but i'll take some pics and post tomorrow...for the record...

Playing today, i notice one of my EL34 was cherry red

Went through the files and gladly found the old resistor to ground trick...

Matched pair will also be installed.

[Tubetwang]

Chassis/boards from Nik...

272JX Hammond PT/Garnet Rebel PA OT (2x6L6)

Nice bite!

I like it!!

This forum was a great help...thanks!