Simplistic MosFET HV Shunt Regs

If you like it so much that way,why not do the same thing here :lol
Mona

Instead of focusing on portions of the circuit, why don't you design it with your suggestions in the bigger context of a working regulator, and post it here, with results? Challenging is good, demonstrating and sharing is better, in the spirit of this forum.

Hundreds of DIY's (or more...) have built and are using the SSHV2 with great performance AND listening results. If you believe you have something that would better this proven design, I think everyone would love to see the working model! :cool:
 
Instead of focusing on portions of the circuit, why don't you design it with your suggestions in the bigger context of a working regulator, and post it here, with results? Challenging is good, demonstrating and sharing is better, in the spirit of this forum.

Hundreds of DIY's (or more...) have built and are using the SSHV2 with great performance AND listening results. If you believe you have something that would better this proven design, I think everyone would love to see the working model! :cool:

To start with I couldn't work out how the circuit could possibly work correctly with such a low voltage across the JFET, but it most definitely does work. :)

Alex
 
Alex M said:
To start with I couldn't work out how the circuit could possibly work correctly with such a low voltage across the JFET, but it most definitely does work. :)
Alex
Sure it works,I never said it didn't.But not as it shoud,the CCS isn't really one and the zener there is useless.
As long as you believe it function well,good for you and the rest of the happy followers.It remains a technical mistake.
Mona
 
Sure it works,I never said it didn't.But not as it shoud,the CCS isn't really one and the zener there is useless.
As long as you believe it function well,good for you and the rest of the happy followers.It remains a technical mistake.
Mona

You have raised the issue.

So please you, you can make a better modification? and more correct??.

Thank you!
 
By curiosity one can wonder how something that outperforms most competition, are rock solid stable and are easy to DIY can be a technical mistake.

Are we talking religion here?

Staffan

Well said, except for religion part. THis is audio, afterall:D

I would be more than willing to test any options forwarded, but must confess that I think that some alternative must be presented or else its just farting in the wind.
 
Member
Joined 2011
Paid Member
except for religion part.

I didnt meen to offend about religion per se. I could have said taste, belief, ones standards, cup of tea or whatever. Sorry.

What I ment was that everybody is entitled to one and its not about right or wrong.

In this area, audio and electronics wrong can be things that malfunctions, are hazardous etc. Otherwise what works works.

Staffan
 

iko

Ex-Moderator
Joined 2008
I used that same zener in my regulators without thinking too much about it, and in practice I know that it saved the jfet (used to have spontaneous dead jfets in that position). But yes, the issue was raised, we should probably address it. Is it an error, in theory, or not? I'm not so sure how a voltage spike would look across the bjt diode in parallel with the zener.
 

iko

Ex-Moderator
Joined 2008
Instead of focusing on portions of the circuit, why don't you design it with your suggestions in the bigger context of a working regulator, and post it here, with results? Challenging is good, demonstrating and sharing is better, in the spirit of this forum.

I have to agree with the fact that there is a lot more value in considering the entire context as opposed to one small part of the circuit. Some of the important features of the circuit will change even with small isolated changes. I know because we've seen it many times. It's nice to get errors pointed out though.
 
diyAudio Chief Moderator
Joined 2002
Paid Member
Sure it works,I never said it didn't.But not as it shoud,the CCS isn't really one and the zener there is useless.
As long as you believe it function well,good for you and the rest of the happy followers.It remains a technical mistake.
Mona

Lets see what LTSPICE says, shall we?

In the OLG pics: CCS as connected originally and as you advise. Connected by your suggestion gives same open loop gain, but 21 degrees less phase margin and more undulation.

In the Zout pics: Orginal circuit, then your bypassed Zener level shift suggestion still with your CCS connection suggestion. I used 100uF as bypass. The output impedance shoots up.
 

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Lets see what LTSPICE says, shall we?

In the OLG pics: CCS as connected originally and as you advise. Connected by your suggestion gives same open loop gain, but 21 degrees less phase margin and more undulation.

In the Zout pics: Orginal circuit, then your bypassed Zener level shift suggestion still with your CCS connection suggestion. I used 100uF as bypass. The output impedance shoots up.


As most of us have already experienced, Salas designs in context of complete circuit performance. The proof is in your design, physical results (implementation) and sound performance.
Let's put this to rest. :yes:
 
What is the maximum of the capacitance allowed after the shunt (as part of the load). I of course have the Zobel.
Is it zero, thus no extra decoupling?
In the LV Salas there is seen 220 uF in the initial schema. But I can not find a reference to the capacitance following the shunt. All scjhemas just show the shunt.
  • I am contemplating 30 uF at 200 V, because mainly it is already part of the schema for each channel of which I am replacing the power supply.
  • Could I insert a small resistor before the final cell, say 2 ohms, to break the HF path?
Better to ask than spend a lot of time looking at something I can't measure anyway :scratch1:

albert