Power switch pop

[Leevi]

Have handled this earlier but thought to take it up again with some solutions that work for my current issue. Actually my question is which one of those 4 alternatives do you recommend and are they all safe as long term solution?Alternative 4 has a drawback since it consums current even if the amp is not turned on.
/Leevi

[Williamblake]

What would pop with a tube rectifier i wonder. No4 looks pretty stupid for obvious reasons as already been said.

[Leevi]

What would pop with a tube rectifier i wonder.

It pops when I turn off the amp. I have also noticed that it is depending on the PT.
In this particular case I changed the PT and this issue did not exist with the previous one.

/Leevi

[Williamblake]

Maybe it is the relay not the rectifier?

[Leevi]

relay

?


/Leevi

[Williamblake]

The change in fragreance is causing the pop. The chanelle switching. Definately not the Pt or rectifier. You would be first. Seriously, what popping circuit are you talking about?

[Williamblake]

On a side note, to cause a pop you would have to have someting in your circuit that changes signal voltage speed-of-sound-fast. A vacuum tube rectifier power supply on planet earth would not be able to do that me is sure.

[Leevi]

The change in fragreance is causing the pop. The chanelle switching. Definately not the Pt or rectifier. You would be first. Seriously, what popping circuit are you talking about?

Yes, the source of the pop can be anywhere in the signal path but in this case the behavior is different with the old and new PT. And all the fixes I listed are located in the power supply.


I hope someone could give a technical explanation for power switch pop which is very common in tube amps.


/Leevi

[Williamblake]

"power switch pop which is very common in tube amps."

That is news to me. So i am stepping back for somebody else to ask for a shematic.

[Leevi]

That is news to me. So i am stepping back for somebody else to ask for a shematic.

Maybe I should add that it is common in the amps without standby switch.


/Leevi

[pdf64]

I think popping when powering down is reasonably common.

To save anyone else the trouble, a PMR209 is a RC snubber https://www.robot-electronics.co.uk/products/pmr209.html
I suggest to combine 3 and 4.
And 2, but moved to the primary.

That’s possibly more mitigation than absolutely necessary, but the multi pronged approach should resolve the issue.

[Williamblake]

That is news to me. So i am stepping back for somebody else to ask for a shematic.

Maybe I should add that it is common in the amps without standby switch.


/Leevi

Sounds like all the amps i ever built. Never had a pop ever. Begging to be educated.

Even the solid state rectified amp with 6 EL34s i had did not give a noise worth writing home about when powering on or off. I am still thinking the problem is somewhere else.

[Leevi]

Here is discussion of this topic in another forum. My case concerns 5D3.


https://www.tdpri.com/threads/which-power-switch-pop-solution-for-5e3.1058180/


/Leevi

[sluckey]

Just use Rob's simple solution. Heck, a .01µF cap looks like a 265K resistor to 60Hz line. Very small current when switch is off.

[Leevi]

I ended up to use PMR209 (100n+100R) even if the idle consumption is ~8mA.It works great, you can't even hear a small snap when switching off.
/Leevi