audio-talk

I am interested in using a 32x Zener string (for 180V output) as voltage regulator and ripple filter between a minimally filtered 220V HT (200 Ohm/47 uF and 1200 Ohm/20uF filter) and Ale Moglia's gyrator board feeding 120V at 25mA into a CX371a. My question is whether the Zener string is appropriate for this use, and whether it can be used without an accompanying CCS (as presented in Morgan Jones text.)

There's lots of info from a group buy thread here;

https://www.audio-talk.co.uk/phpBB3/vie ... php?t=6204

According to the build manual from that project 32 zeners will give you 183V.

That said, I'm not sure your use case is really necessary - I asked Ale about using a regulated power supply in front of his gyrators and he said a CRC pre-filter was sufficient.

I've just assembled one of the group buy kits to use with a pre-amp project.

The statistical reg is effectively a zener diode. As such it will need to be driven by a load of some sort, either a resistor, or a current source. In both cases the load will have to be low enough such that the required current and shunt current is available (and the dissipation in the zeners is within limits) and high enough such that the zener will not self destruct when the load is removed (for example a failed filament). A CCS lets you do that better and provides higher immunity from the source supply.

In effect the CCS is what provides the immunity from noise the zener the voltage regulation.

If you did want a shunt regulator there I would have thought VR tubes may have been more in keeping.

Yes I use vr’s but they’re a pain because of the few voltages available, which matters when their final cathode voltage is positive relative to ground for biasing a class a2 grid . I often think about making life a lot simpler using zenners, or hybrid zenners filling in the holes in available vr voltages. Otherwise valves can cook. Whenever I make anything of that nature, after caclulating, comes the empirical test heart in mouth! Sometimes valve conscerned cooks, (until the right adjustments are made) sometimes not. Making a stepped zenner selector would make the heart in mouth part of the process much swifter.

Yes I use vr’s but they’re a pain because of the few voltages available

Yes, but in this case 180v is just two 0b3's

Its always nice when it’s like that.

I bought the kit Nick put together but Ive lost it.