Smashup Voltage [resolved]

1026mind · 6445

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Offline Paul Birkeland

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Reply #30 on: February 22, 2022, 11:05:33 AM
In your build where does the power supply connect to the chassis?

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline 1026mind

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Reply #31 on: February 22, 2022, 11:31:42 AM
everything goes to a grounding post.



Offline Paul Birkeland

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Reply #32 on: February 22, 2022, 11:37:23 AM
You have umbilicals in your build, so is each chassis plate connected through the umbilical?

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline 1026mind

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Reply #33 on: February 22, 2022, 11:51:27 AM
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 .



Offline Paul Birkeland

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Reply #34 on: February 22, 2022, 11:56:33 AM
so you have each chassis plate connected through the audio ground?

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline 1026mind

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Reply #35 on: February 22, 2022, 12:19:15 PM
yes Sir



Offline Paul Birkeland

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Reply #36 on: February 22, 2022, 12:41:18 PM
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.


Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline 1026mind

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Reply #37 on: February 22, 2022, 01:02:30 PM
audio ground would be the part where the RCA are connected to the ground?



Offline 1026mind

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Reply #38 on: February 22, 2022, 01:04:25 PM
never mind my last comment



Offline 1026mind

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Reply #39 on: February 22, 2022, 02:44:10 PM
just finished and its still a little buzz



Offline 1026mind

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Reply #40 on: February 22, 2022, 03:17:19 PM
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?



Offline Paul Birkeland

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Reply #41 on: February 22, 2022, 04:11:40 PM
What is at the input of the pre? Just jacks wired to the grids of the 4P1L?

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline 1026mind

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Reply #42 on: February 22, 2022, 05:00:54 PM
yes



Offline Paul Birkeland

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Reply #43 on: February 22, 2022, 05:15:27 PM
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.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline 1026mind

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Reply #44 on: February 23, 2022, 03:49:52 AM
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