5e3 build super low output??

[mbailey]

hey brother THUD in your dwg of the 5e3 w/6aq5's are you letting the preamp filter cap ground thru the input jacks? also it appears you are doing the same with the other caps?? I guess the only thing I see grounding to a lug is the AC GROUND?

[loudthud]

There are almost as many ways to connect ground in an amp as there are people who build them. This makes it very difficult to diagnose what's causing the problem when someone's new build has hum. Sometimes it's the heater supply or input jacks, many times it's ground related. Ground problems revolve around anything that's connected to the chassis, especially input and speaker jacks. I can only suggest a solution but cannot offer a guaranty. I've tried to explain the philosophy behind my method several times, I won't repeat it here. Do an Advanced Search for combinations of words: chassis, ground, jacks, O'Connor, coax, filter, center in posts by me. Look for one of the TUT books with a chapter titled 'The Right Connections'. (TUT 2 I think)

When you turn down both volume controls, is all the hum gone or just most of it? What about when you pull the first preamp tube. Is the hum reduced or changed any with volume controls up or down?

For your amp try this. Run a wire from the ground side of the cathode resistor for the preamp to one of the ground tabs on the input jacks.

Maybe something usefull in this thread: http://music-electronics-forum.com/t12254/

[mbailey]

When you turn down both volume controls, is all the hum gone or just most of it?

pretty much all goes away

What about when you pull the first preamp tube.

it goes away

Is the hum reduced or changed any with volume controls up or down?

the hum goes up and down in volume with the volume controls
I'm gonna try some of your suggestions and see what happens
I really appreciate all your help and ideas

[mbailey]

Finally no hum or very little anyway. THANKS BROTHER LOUDTHUD I looked at your ground schemes and move the GND wire from the preamp filter cap and grounded from the very first preamp cathode to the input jack gnds and TADA no hum. I knew it was gonna feel good when i got to the bottom of this!! & to everyone else who gave advice I sincerely appreciate the help. this has been a grat learning experience for me & I hope to be able to share my experiences with another new builder some day!