cathode bypass caps voltage in princeton reverb

[J&F]

First I want to thanks all of you for all I could learn on this Forum, what a great mix of passion, knowledge and generosity.
I got a 79 "blackfaced" sfpr (AA1146 schem). I want to try others cathode bypass caps values, 4.7 uF, .68uF ... and maybe a switch to choose from one to another, which voltage rating for those non electrolytic caps? not 630volt I guess.
And is it only interesting in V1a, or V1b and V3b are concerned too?
Thanks for your help.

[Chuck H]

Almost any value above 1uf is much easier to find in an electrolytic type cap. These caps are polarized and so must be installed in correct polarity. Voltage at the cathode of preamp tubes is seldom above 10V (usually under 2V) unless it's a circuit that would not use a bypass cap. So anything rated 15V or higher is fine.

[Jazz P Bass]

First I want to thanks all of you for all I could learn on this Forum, what a great mix of passion, knowledge and generosity.
I got a 79 "blackfaced" sfpr (AA1146 schem). I want to try others cathode bypass caps values, 4.7 uF, .68uF ... and maybe a switch to choose from one to another, which voltage rating for those non electrolytic caps? not 630volt I guess.
And is it only interesting in V1a, or V1b and V3b are concerned too?

Thanks for your help.

V1 A is the tube that the cathode bypass has the most effect on.
The higher the capacitance, the more bassy it will sound.
I would not go above 25uf.
25V is a good rating.