Cathode switching pop noise.

[psychepool]

I made a vintage marshall amp.
It is based on "Plexi 6v6".

The special feature is jtm/jmp cathode switch.
I switched it like this.

http://s935.photobucket.com/user/psyche ... sort=3&o=2
Dpdt switch is push-pull pot.

It operates well, but has a big problem.
Very very very loud pop noise...
It loud than guitar signal!!

And I switched tone stack too.
Like this.
http://s935.photobucket.com/user/psyche ... sort=3&o=1

It pops loud too!!

Can I eliminate or reduce the pop noise?
A few noise is alight, because I will not switch it while play guitar.


Give me a solution please.



*Additional question*

http://s935.photobucket.com/user/psyche ... sort=3&o=0
Are these the same result?

[romberg]

*Additional question*

http://s935.photobucket.com/user/psyche ... sort=3&o=0
Are these the same result?

No. They are not the same. If two tubes share a cathode resistor then that resistor will have twice the current flowing through it compared to the case where each tube has it's own resistor. So the bias points of the tubes will be different. That is also contributing to the pop you have when switching.

Mike

[LOUDthud]

Try this:

[psychepool]

Oh Thanks romberg. The value must be twice!

[psychepool]

Thanks LOUDthud. That's good idea!!

Can I eliminate pop noise with this parallel switching?

[romberg]

Oh Thanks romberg. The value must be twice!

V = I * R

If V is your bias voltage (that you want to make the same then:

I * R1 = (2 * I) * R2 (where R2 is shared and R1 is not)

R1 = 2 * R2

R2 = R1/2