light hum on the crack #2 [resolved]

[Tim]

I just completed my build, Crack with Speedball, and also have excessive hum and a slight random low level crackle on the right channel.  I have swapped input cables with known good cables, checked and resoldered connections.  I have Sennheiser 650 headphones that sound perfect with other amps.  Looking for solutions.

[Paul Birkeland]

Did you build the Crack stock first?

[Tim]

No, I built the Crack and Speedball simultaneously.  Didn't see the need to complete and disassemble Crack for the Speedball modification.  Additionally, I have rolled all tubes and problem remains.  I suspect the random scratch is due to a component issue on the small "A" circuit board. 

Other than these issues the amp sounds great.  Once I address the annoying right channel issue I'll learn to live with the hum or take additional steps to address it.  Suggestion for reducing hum are welcome.

[Paul Birkeland]

Please remove the Speedball and put the loading resistors in, then repeat your test.  Your assessment is speculation that may be proven incorrect by performing this test.

[Tim]

Grounding issue identified and corrected, no hum or right channel noise.  Thanks for your assistance.