Smashup Voltage [resolved]

[Paul Birkeland]

In your build where does the power supply connect to the chassis?

[1026mind]

everything goes to a grounding post.

[Paul Birkeland]

You have umbilicals in your build, so is each chassis plate connected through the umbilical?

[1026mind]

they are two umbilicals, one for the filament of the 4p1l's that is two wires and the other has 3 , one is ground and the other two are both 150v, one for each channel .

[Paul Birkeland]

so you have each chassis plate connected through the audio ground?

[1026mind]

yes Sir

[Paul Birkeland]

That is a potential source of noise.  Ideally you would have the chassis plates connected together through their own wire in the umbilical and that would be hard grounded to the E lug on the IEC power entry module, then the audio/power supply ground would run separately and you would put the antiphase diodes in the amp section between the audio ground and the chassis.

[1026mind]

audio ground would be the part where the RCA are connected to the ground?

[1026mind]

never mind my last comment

[1026mind]

just finished and its still a little buzz

[1026mind]

now I don't know if you noticed but I don't have the pots nor the attenuators at the input, I'm just using the volume from my OPPO player.
could that be the reason for the little buzz/noise?

[Paul Birkeland]

What is at the input of the pre? Just jacks wired to the grids of the 4P1L?

[1026mind]

yes

[Paul Birkeland]

You should have a 47K resistor from grid to ground on each 4P1L.  If you pull the RCA cables, the grid has no ground reference and that can cause damage to the 4P1Ls.

[1026mind]

when I purchased the smashup upgrade I got the smash quiet to. I want to built it but I have do diagram. Is it possible to get one?
Thank you! Btw I'm waiting on the attenuators, they are in the mail from France