RE: "Singing" Power Transformer

Posted by mikeyb (A) on October 14, 2019 at 18:55:21

In Reply to: RE: "Singing" Power Transformer posted by trobbins on October 14, 2019 at 16:28:16:

Thanks for the analysis. I was curious, so attached a 11:1 external resistor divider from cathode to ground. Then measured the voltage with an oscilloscope. It confirms your analysis. The peak positive voltage at the cathode measures approximately 610 volts with the amp connected (an approximate 100 ma load).

I ordered a 6.3 VAC 4 amp filament transformer (Hammond 167N6). Will also have to replace the 12 amp filament transformer with a 6 amp version in order to squeeze two transformers into the space the 12 amp version occupies.

Would it be better to let the center tap of the transformer connected to the 6CA4 filaments "float" (leave disconnected) or tie it to 300 VDC?

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Follow Ups Full Thread

Topic - "Singing" Power Transformer - mikeyb 07:35:48 10/11/19 (18)

RE: "Singing" Power Transformer - FenderLover 07:01:35 10/13/19 (0)

RE: "Singing" Power Transformer - trobbins 03:18:25 10/13/19 (6)

RE: "Singing" Power Transformer - mikeyb 11:37:10 10/13/19 (5)

RE: "Singing" Power Transformer - trobbins 18:18:57 10/13/19 (4)

RE: "Singing" Power Transformer - mikeyb 09:57:46 10/14/19 (3)

RE: "Singing" Power Transformer - trobbins 16:28:16 10/14/19 (2)

RE: "Singing" Power Transformer - mikeyb 18:55:21 10/14/19 (1)

RE: "Singing" Power Transformer - trobbins 22:17:39 10/14/19 (0)

Can you feel the vibrations on the laminations... - FenderLover 18:47:37 10/11/19 (4)

RE: Can you feel the vibrations on the laminations... - mikeyb 20:02:44 10/11/19 (3)

"Holding the transformer's hosing stops the noise.Holding the transformer's hosing stops the noise." Bingo! - Chip647 20:48:59 10/11/19 (2)

RE: "Holding the transformer's hosing stops the noise.Holding the transformer's hosing stops the noise." Bingo! - mikeyb 07:36:53 10/12/19 (0)

Rubber Washers - Triode_Kingdom 01:46:30 10/12/19 (0)

RE: "Singing" Power Transformer - Triode_Kingdom 16:55:52 10/11/19 (1)

RE: "Singing" Power Transformer - mikeyb 17:31:47 10/11/19 (0)

Yes. Tighten down the bolts securing the end bells. - Ralph 12:20:59 10/11/19 (0)

did it always sing? - elblanco 09:44:20 10/11/19 (1)

RE: did it always sing? - mikeyb 16:45:16 10/11/19 (0)

Follow Ups

RE: "Singing" Power Transformer - mikeyb 18:55:21 10/14/19 (1)

RE: "Singing" Power Transformer - trobbins 22:17:39 10/14/19 (0)

RE: "Singing" Power Transformer

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