Simplistic Mosfet HV Shunt Regs

[AndrewT]

Originally posted by Salas
What are you going to power with it

anything that might benefit from a CCS shunt regulator,
i.e. every electronic circuit that is not a power amp.

[disco]

Originally posted by AndrewT
anything that might benefit from a CCS shunt regulator,
i.e. every electronic circuit that is not a power amp.

What's against stable, low impedance power with low noise and great bandwith for an amps' PS?
Do you perhaps hint at the use of active anode loads making the pro's of a shunt superfluous?

Thinking about an all electrical supply for a new power amp I soon abandoned the idea as the driver
tube needed a higher anode voltage than the output tubes.
I gave up on the idea of a series type regulator in front of the shunt, because dissipation becomes
substantial for a 20+20W tube amp.

It might do miracles on small power amps though, like the Darling which operates at a single HT voltage.

[AndrewT]

Hi,
a power amp can be made to work in conjunction with a regulator, if one's design expertise is up to the task.

But a shunt regulator, surely, can't be a candidate for a power amp's supply?
I would think if one is going down this route one would select a series regulator topology.
Maybe I'm wrong.

[disco]

The most positive aspect of a shunt regulator is its ability to swamp current. This might explain the (subjective) worse sound quality obtained with a series type regulator.

[AndrewT]

Hi,
try doing that on a power amp with shunt regulator.
How much power do you plan to use to swamp the power amp consumption?

[disco]

Originally posted by AndrewT
Hi,
try doing that on a power amp with shunt regulator.
How much power do you plan to use to swamp the power amp consumption?

That's another cup of tea
In case of a shunted power supply one has to know exactly the maximal current draw. That depends not only on the steady state condition but also on the clipping state on loud passages. The latter best be under 80% of the total current set in the shunt. It is largely depending on topology and measures to prevent clipping (feedback?) but should be determined by experiment and measurement.

[Salas]

The higher the bias and the bigger the sinks or constant tube dissipation of the audio unit the better the customer for a shunt it is. Small class A like JLH69 and 96 for the low voltage version or small SE amps for the HV version are in for a nice reg and amp package. If the juice is already burned then the shunt only has to top it for headroom. Keeps the shunt constant waste at minimum.

[disco]

Salas,

Will the amplifier suffer from limited bandwith when the shunts' current headroom is exhausted, which might occur on peaks?
I can imagine it's only of minor importance compared to the effects of blocking for instance. But still...

[Salas]

If it has loop feedback it will to the most I presume.

In general, stiff supply sounds less powerful if the amp can not satisfy the speakers is paired with. Sag tends to breath with and its a form of soft compression. The key is to take measurements and know what are the real peak demands on certain speakers and listening habits so to efficiently set the reg without burning too much just to have spare or less than really needed.

[disco]

Not being very gifted with solid state I ventilated this [OT] idea some time ago to Gary Pimm.
It's more appropriate to larger amps than to sputs but it might be worth the effort.

In order to optimize a shunt regulators' efficiency it should be able to change its set current when
power consumption is demanding such. A kind of servo action. Would it be possible to sense the
ampliers' current draw ahead of the actual amplification and adjust the CCS as needed?
The biggest bottleneck might be the slowness of the current rise.

A very simplistic (hey, where did I hear this before ) solution would be a 10 to 20% increase
depending on the rotation of the volume control.