Look for high-voltage regulator projects

[janneman]

Originally posted by Radioman62


Why? Where have you learned that? Can you please elaborate or show some theory.
The design I refer to above, the shuntregulator on this forum says 0.2 times the load.

I recently read somewhere at John Broskies Tubecad that it's a misunderstanding that the shunt needs to draw more then the load. Can't find it right now though.

The important thing is the *variation* of the load current, not the absolute value. The shunt current must be at least as large as the variation in load current to maintain a current at the highest load current. The thing you set is the CCS feeding the shunt and load, the shunt regulates itself.

Suppose you have a load that varies between 800mA and 1200mA. Then make your CCS feeding the shunt and load to deliver 1300mA. Then at 800mA load current, the shunt absorbs 500mA, and at max load of 1200mA, the shunt takes the remaining 100mA. So, the shunt always stays in control.

Jan Didden

[Allen Wright]

It's possible I am the source of the idea that shunt current must be at least equal to that drawn by the load. I say this quite strongly in my "Tube preamp CookBook" in the chapter on current sourced shunt regs. And as there are over 2000 copies of this book out there, mayhbe the idea has gotten around.

Since writing that, I have found you can get away with much less shunt current than what the load draws, but never so low that the shunt never has any shunt current left on peaks of current in the load.

In our big RTP3D preamp, each channel draws 75 mA, and I set the shunt current to 20mA. Works just fine and there's no sonic advantage in having more shunt current than this.

Regards, Allen (Vacuum State)

[janneman]

Originally posted by Allen Wright
It's possible I am the source of the idea that shunt current must be at least equal to that drawn by the load. I say this quite strongly in my "Tube preamp CookBook" in the chapter on current sourced shunt regs. And as there are over 2000 copies of this book out there, mayhbe the idea has gotten around.

Since writing that, I have found you can get away with much less shunt current than what the load draws, but never so low that the shunt never has any shunt current left on peaks of current in the load.

In our big RTP3D preamp, each channel draws 75 mA, and I set the shunt current to 20mA. Works just fine and there's no sonic advantage in having more shunt current than this.

Regards, Allen (Vacuum State)

Allen,

I quite agree with you.

Jan Didden

[revintage]

They're in production! I expect them end of next week.

Great,
The layout looks nice. The first one I will try is a above 700V 6C33C regulator with the board some centimeters below the socket. Will come back when I have the boards.

[Radioman62]

Originally posted by Allen Wright
It's possible I am the source of the idea that shunt current must be at least equal to that drawn by the load. I say this quite strongly in my "Tube preamp CookBook" in the chapter on current sourced shunt regs. And as there are over 2000 copies of this book out there, mayhbe the idea has gotten around.

Since writing that, I have found you can get away with much less shunt current than what the load draws, but never so low that the shunt never has any shunt current left on peaks of current in the load.

In our big RTP3D preamp, each channel draws 75 mA, and I set the shunt current to 20mA. Works just fine and there's no sonic advantage in having more shunt current than this.

Regards, Allen (Vacuum State)

I see. Nice of you to admit that. It could very well be so. I thought I understood the shuntregulator before and now I feel even better.
One thought. Is it maybe overkill to use such a shuntregulator on a Constant Current Draw Grounded Cathode amplifier? I mean it doesn't tug alot on the powerline, even though it's PSRR isn't the best of the tube circuits. Maybe it's best on such an amp because of the low PSRR figures?

[Allen Wright]

Radioman,
If your common cathode stage uses a CCS as a anode load, then adding CCS fed shunt reg may not help much, but if it is a regular resistive loaded CC stage, or is a SRPP (or similar) then it will GREATLY help. By actual test.

I believe a CCS fed Shunt reg is VITAL in all signal handling stages, that's why we have been selling our "SuperReg" kit for over 10 years now!

Regards, Allen (Vacuum State)

[LinuksGuru]

Originally posted by janneman


I tried 10 ohms in my own T-reg regulator. Too low. I settled on 100 ohms.

Jan Didden

Sorry, missed a topic, which resistors are you talking about? Is it about DN2540 or tube version?

[janneman]

Originally posted by LinuksGuru


Sorry, missed a topic, which resistors are you talking about? Is it about DN2540 or tube version?

DN2540 or DN2470. For the tube versions you can use up to 1k since the grid capacitances are much less than the gate caps.

Jan Didden

[LinuksGuru]

Originally posted by Allen Wright
Radioman, If your common cathode stage uses a CCS as a anode load, then adding CCS fed shunt reg may not help much, but if it is a regular resistive loaded CC stage, or is a SRPP (or similar) then it will GREATLY help. By actual test.

I believe a CCS fed Shunt reg is VITAL in all signal handling stages, that's why we have been selling our "SuperReg" kit for over 10 years now!

Regards, Allen (Vacuum State)

Although regulated stabilized power supply will certainly benefit tube gear from the point of view of engineering, I have not seen any blind listening tests which will confirm that regulated PS does really improve sonic performance, especially when it comes to tube pre-amps, which draw very little constant current. Better characteristics on oscilloscope do not necessarily translates in something audible.

I have to admit I plan to use regulated PS for power amp, but for purpose of better preservation of output tubes.

[radianceaudio]

I would just throw in a comment here: blinded tests don't work.

Non-blinded tests don't work, either, but there's a caveat to that:

educated testing works, depending upon who's ears you're trusting.

There are a few ears I trust. Wright's. Pimm's. Broskie's. a few others.

You'll find this hard to understand, I know. For an explanation, you can read:

http://www.transformationaudio.com/b...ousticsofAudio

Important note: this is an explanation only, containing a hypothesis. It is not a proof. There is no proof, yet. Until we can free ourselves of the belief that engineering understands neuroacoustics - it doesn't, it only understand electronics (barely), an entirely different matter - and figure out how to do valid psychoneurologically-based neuroacoustic testing of audio components, the only foundation we have are educated ears that have done this work for many years. See above.

50 years ago, music was fun. I didn't really care about hifi, I just enjoyed.

20 years ago I thought I knew something, but it was all baloney; I had been tricked by the illusion of specifications.

5 years ago I realized most of what engineers said about audio was also baloney, but the field of audio is filled with landmines, placed there by both engineers, frauds, con-artists, lunatics, and people who must be from other universes, so it took me some time to parse out who's ears I could trust and who were nutcases. Mind you, the best educated ears are also good engineers, but the reverse doesn't follow at all.

Now, I trust the judgment of a very select few educated ears. There is a consensus: for preamps, CCS'd Shunt Regulation is the way to go. Period. For a preamp, I'd use Allen Wright's power supply kit in a heartbeat. It's a no-brainer. For power amps, I'm starting to lean in the judicious application of CCs's also, as Pimm is demonstrating.

Being a DIY'er, I waste time and money designing my own, but I take very careful lessons from those who've done the work for a long time, and emulate them.

Best, Charlie