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What is a good value for B+ ripple on 480VDC
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Planobilly:
The next issue.....

Here is how the DC heater supply is connected as built.



I have 6.3 VDC at the preamp heaters with .480 VAC at the heaters.

Scope screenshots....

DC coupled on one side of the bridge to chassis ground



DC coupled on both sided of the bridge.



I am not very skilled with a scope so I am not sure what I a seeing plus I did not expect .480 VAC

Perhaps someone can comment.

Thanks,

Billy
Planobilly:
Basic schematic to the amp.





Billy
tautech:

--- Quote from: Planobilly on December 03, 2016, 06:34:27 pm ---
Scope screenshots....

DC coupled on one side of the bridge to chassis ground

Perhaps someone can comment.

Thanks,

Billy

--- End quote ---
As you want to see the AC component riding on the DC voltage  use AC input coupling, DC coupled trigger (always) and 10:1 (min) probes (preferably 100:1...think safety) and Vertical settings will be in the 10's of mA/div.
Be sure the channel's 0V level is visible on screenshots, maybe shift it lower to show larger/all the waveform.
cvanc:
The output tube B+ supply is before the fuse but the screen grid supply is after the fuse.  What happens in your output stage when the fuse blows?  The screen grids will go to zero volts but the plates will still be on...

I don't see the bias supply on the drawings, but the same worry applies if it will turn off when the fuse blows.



Andy Watson:

--- Quote from: Planobilly on December 03, 2016, 06:34:27 pm ---The next issue.....

Here is how the DC heater supply is connected as built.


--- End quote ---
Isn't that a 6.3V A.C. supply for the output tubes - that's being rectified and smoothed to deliver D.C. to the preamp tubes ? Even allowing a generous 2V drop across the diode bridge you'll still be over-driving the preamp heaters.
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