Loud buzz on 0 volume [solved]

[Paul Birkeland]

I think you might have the grounding jumper issue as described elsewhere in this thread.

[Klots]

I think you might have the grounding jumper issue as described elsewhere in this thread.

Gr
You mean the jumper on the pot? Why is this jumper only an issue when vol is 0? Shouldn't the Graignger49s ground path testing (sticky thread) reveal it?

[Doc B.]

You need to return the circuit to the state it was in before the problem started. See if the problem is gone. Then repeat the change you made. If the problem comes back you know that there is some issue with the new part.

[Klots]

You need to return the circuit to the state it was in before the problem started. See if the problem is gone. Then repeat the change you made. If the problem comes back you know that there is some issue with the new part.

Ok, then it means I just have to install electrolytic caps again..will test that and everything else today.

[serpent68]

Yesterday I got my E80CC tube also, and my crack produces the same buzz with E80CC and 12AU7. Today I will measure resistance and voltages and post them here. Maybe something comes out of them.

You also have caps upgraded or just buzzing with E80CC?

I have Mundorf 100uF film caps fitted together with Speedball from Day 1.  I never have problem when using 12AU7 input tubes.  But when I switch to E80CC or 12BH7, the loud buzzing sound at 0 volume is always there.  Strange to me is that the buzz sound completely disappears when I move away from position 0. There is absolutely no noise, and the sound is very good.

[2wo]

Before you tear everything apart, remove the tube and measure resistance from the center of the RCA  jack, to pins 2 or 7 and from the center RCA to ground, for volume positions 0 and 1...John

[Doc B.]

If I was just reading this and seeing "when I change tubes I have the problem" then I would say it's a tube pin to socket interface issue. However we are hearing that the problem started when the caps were changed. It isn't intuitive why that would cause the problem, but that was the last event that happened before the problem occured.

[Klots]

changed all caps back and now only B4 is 62V and B6 is 84V...all other pins are great, but...still the buzz on 0 vol. AND, I found the problem It is my 5998 tube. I so remembered that with 5998 it was quiet, but no it is not. Will the speedball change something in the circuit for this tube or is it gonna still buzz when I install speedball? I am gonna still use the 5998 tube, but I just wont turn to 0 volume. Thanks everyone and   

[JamieMcC]

changed all caps back and now only B4 is 62V and B6 is 84V...all other pins are great, but...still the buzz on 0 vol.

Have you a different input tube to try as I seem to recall having some similar discrepancies in my voltage checks which turned out to be due to the 12au7 input tube. After  I swapped it for a different one and the voltages measured within a couple of percent of those in the manual .

[Klots]

Have you a different input tube to try as I seem to recall having some similar discrepancies in my voltage checks which turned out to be due to the 12au7 input tube. After  I swapped it for a different one and the voltages measured within a couple of percent of those in the manual .

Seems I was modifying my post when you answered 

[JamieMcC]

Maybe the off voltages from the 12au7 effect the operation of the 5998 resulting in the noise? Just thinking out loud and not really knowing what I'm talking about but hey that's how you find stuff out   

[Klots]

Maybe the off voltages from the 12au7 effect the operation of the 5998 resulting in the noise? Just thinking out loud and not really knowing what I'm talking about but hey that's how you find stuff out   

I use E80CC tube. But I tested with 12au7 that came with the crack and same sound. So I test that 0 vol thing again when I install speedball (in January or February).. Yes Jamie I that way you can find stuff out