Placid-BP Bipolar Shunt Regulated Power Supply

[BrianDonegan]

The Placid (kit) uses FJP5200/FJP1943 devices (80W, 230V, 15A). The only other limiting part are the caps, but they are >=50V. I think you should be fine.

[Beefy]

Originally Posted by tailspn

Actually not. It's all about......

As I said...... and the practical difference is?

Let me explain. I am equal parts technophile, physiologist, and practical to a fault. Part of me wants the absolute best technical solution possible. Part of me wants to know that it actually makes a scientifically testable audible difference. Part of me wants to know whether I can de-OCD to the point where any of it will affect my musical enjoyment at all.

So I guess I'm wondering where we sit in this particular situation. Pure technical pursuit? Extremely minor audible differences? Critical loss of musical enjoyment?

[tailspn]

Thanks Brian!
This should work very well for my applications. Looking forward to the kits.

[iko]

Originally Posted by Beefy

As I said...... and the practical difference is?
...
So I guess I'm wondering where we sit in this particular situation. Pure technical pursuit? Extremely minor audible differences? Critical loss of musical enjoyment?

On high transient current draws the shunt can supply it on demand, with minimal voltage drop. This, of course, depends how good the regulator is. If a voltage drop is audible or not depends on how large the sag is. Most people tend to hear a very non-subtle difference with a shunt, usually as improved dynamics.

[Spirit02]

Hi Brian/Russ,

Any idea when this will be available (next 4-6 weeks?)
I was just about to grab a 32S and the 'standard' ps option, but if this is just around the corner, then might hold out for it.

Would love to hear some comparisons between the two

Cheers,
Phil

[Russ White]

It should be able to handle even 1A load as long as the drop is not crazy into into the reg.

The reg only needs about 3V drop for optimal regulation.

500ma should be no trouble at all.

[tailspn]

Thanks Russ and Brian. This kits should work very well in the applications I have planed for them. Could you please advise what percentage of the load current would you recommend be sunk by the shunt transistor? Aside from the loads inrush current at start-up (charging all the capacitors), the + and - 400MA appears relatively constant under signal conditions. All of the opamps run Class A, and the load on them is above 2K Ohm. I'll measure the delta current before I build the kits and know exactly.

Thanks again,
Tom

[Russ White]

I don't have any solid data yet to back this up, but I would recommend using your maximum AC load(delta current) + 20-50ma + static load.

The shunt part of the circuit utilizes a CFP. The idea is to keep somewhere between 2-10ma going through the CFP driver. This helps it run in its ideal region.

I currently have mine running at 300ma with a static load of about 200ma and a dynamic load of 10-50ma depending on if I am driving headphones. This seems to give me plenty of reserve current.

You can experiment and find the sweet spot for your application.

The supply is pretty forgiving.

[tailspn]

Please excuse my being dense. I interpret from your explanation that the entire supply (one polarity) would draw the maximum AC load(delta current) + 20-50ma + static load. The shunt element of the regulator would be adjusted to draw the max AC Load (delta current) plus 20 to 50ma. I'm just trying to get a rough idea of the power dissipation of each of the power transistors on each polarity of the supply. With 4V or so drop across the series pass transistor, the dissipation for .5A is only 2-3W. With 100ma through the shunt transistor, at 24V, that's less than 3W. This is of course only one polarity, but much less heat than I originally thought. Am I missing something?

Also, what does CFP stand for? Constant something I'm sure.

Thanks again,
Tom

[eclectic2k]

Originally Posted by Russ White

...
I currently have mine running at 300ma with a static load of about 200ma and a dynamic load of 10-50ma depending on if I am driving headphones. This seems to give me plenty of reserve current.

You can experiment and find the sweet spot for your application.

The supply is pretty forgiving.

How do you think this would work with IVY or Ballsie? If I understand correctly how you've configured it, Placid should be a good upgrade to your LCBPS for most applications...?

I'm planning to order an Opus ASAP, along with an IVY as a balanced buffer and SE converter. A Placid would be a great touch. (even if I need to wait a bit for it)

Thanks!