Vox AC50 tried and tested capacitator couples bias supply replacement?

[Balticnoiseforge]

Is there any circuits out there for a capacitator coupled bias supply like those in Ampeg, JCM900 etc to replace the original vox AC50 one with?

Thought someone already may have calculated out one since original is using alot of parts to generate the bias voltage.

Best regards.

[sluckey]

The JCM900 is as simple and reliable as it gets. Just copy that.

[kagliostro]

In my opinion it would be better to keep things as they are, in some VOX there were problems with the Bias circuit and that circuit seems to be the result of studies aimed at avoiding problems

If instead you want to go simply go as in the Marshall



K

[Balticnoiseforge]

In my opinion it would be better to keep things as they are, in some VOX there were problems with the Bias circuit and that circuit seems to be the result of studies aimed at avoiding problems

If instead you want to go simply go as in the Marshall



K

I suppose it is the cost of 4uF 350v capacitators that iam trying to avoid, not totally sure how the circuit really work and how much difference changing the 4uF value to 3.3uF-4.7uF would do, but yeah there are also film caps rated at higher voltage that could be used.

When it comes to capacitator coupled i was thinking about something like this, that should be working, although i have never used cathode coupled with two bias potentiometers before, so would probably have to experiment abit to see if it is a good idea for pots to share a tail resistor or if both should have a independent.

But ill consider both of yours advice! Thanks