dc 30 problem

[ronman]

I just finished my dc30 build, the amp sounds great except for one problem, when you turn up the treble past 3/4 the sound kind of gets scratchy and the volume goes down.I also noticed when you turn the volume up past 1/4 a hum starts even with the guitar unpluged its like it switches on. with the guitar plugged in it plays fine up to 1/4 then switches on .The ef86 channel sounds fine.

[M Fowler]

Run shielded wire from V2 to volume pot wiper.

Make sure 47pf mica treble cap isn't allowing dc voltage on the treble pot.

You also have the other volume pot wired to the effects jack on back as well that could introduce hum.

[ronman]

I just wanted to let you know that I got the amp fixed all I had to do was put a shield in front of the output transformer now every thing is fine.


Thanks for the help

[M Fowler]

Glad you followed my instructions so well.

[daydreamer]

hi Ronman,

Do you mean shielded wire or an actual earthed barrier of some sort?

thanks

Andy

[M Fowler]

I believe he use a piece of metal in front of the transformer.

[ronman]

Yes I did use a shield in front of the OT and it worked like a charm.Here is a picture.

[Structo]

That's what I call creative license.

If the red and black heater wires are resting on top of the shield you may want to provide some kind of abrasion relief there.

You gotta think long term and what might happen after a year or more of use.

[ronman]

Thats just after installation.The wires have been rerouted.

[mumford]

That's what I call creative license.

The ceriatone hot cat kit uses the same thing.

[M Fowler]

I have seen some amps that encase the whole bottom of the transformer to shield it.