3 terminal Jung Super Regulator Kit

[peranders]

Originally posted by janneman
I don't know how to reach him though (except through AudioXpress) as he seems to have retired from Analog Devices.

I have had contact with Mr. Jung recently (April) about FNDR filter.

[janneman]

Well, ALW will probably beat me to this (Hi Andy!) but believe me, in this designb EVERY (almost) component is tweaked, the reference, the opamp, the caps, the feedback circuitry, and yes, the bootstrapping of the opamp supply. Each giving measurable improvements and, as I have heard from other users, audible differences.

On top of that, the PCB layout has a MAJOR impact on the performance. A couple of wrongly routed traces can negate that expensive opamp or cap completely.

This is not for the faint at heart. If you see designs still using the 797 they either don't use remote sensing or use excess compensation to keep it stable or take a gamble.

Do yourself a favor and buy the 1995 backissue series of AudioXpress. Well worth the 20 $ or so it costs.

Jan Didden

[Norbert]

Hi,

the later called Jung Design has been used by Akihiko Kaneda in the seventies already within all of his DC-Amplifiers published at that time using 709 opamps.

Best regards,

Norbert

[janneman]

Originally posted by Norbert
Hi,

the later called Jung Design has been used by Akihiko Kaneda in the seventies already within all of his DC-Amplifiers published at that time using 709 opamps.

Best regards,

Norbert

" There is nothing new under the sun, but there is a lot we haven't seen yet" -- Anon

Jan Didden

[peranders]

Originally posted by ALW


As always with audio, the final circuit sound has little to do with the topology used.

The benefit of the o/p stage is primarily that it allows a start-up mechanism for the bootstrapped regulator, and the subsequent (big) benefits of that

Oki doki, I had some startup problems with my negative regulator but I suspect with a true rail-to-rail opamp would solve the problem. The opamp I used LM324 can have the inputs at ground but not at the power supply voltage.

[dipchip]

peranders,

The real benefit comes from the bootstrapping the op-amp.

This means that the op-amp is powered directly from the regulated output voltage of the circuit.

Normally, if the op-amp were powered from the supply, any ripple on the op-amp supply would show up as noise on the output.

But now, the regulated output powers the op-amp,
and the regulated output is also the feedback to the op-amp.
So the noise is now much more common mode, and hence the
big 30 to 35 dB improvement over typical regulators.

Thanks,
Craig Beiferman

[ALW]

Hi Jan,

I've been corresponding with Craig privately about those issues (e.g. PCB layout).

With uV error signals, the PCB is an essential part of the circuit!

I don't mine helping for the greater good of the DIY community though, and have wanted to do an SMD version ever since I did my board

I reckon there's a good market for a 3-terminal replacement that crams as much performance as we can muster into a suitable footprint.

Andy.

[janneman]

Originally posted by peranders

Oki doki, I had some startup problems with my negative regulator but I suspect with a true rail-to-rail opamp would solve the problem. The opamp I used LM324 can have the inputs at ground but not at the power supply voltage.

It's not that Per. If the opamp supply is bootstrapped, it can not regulate the output voltage away from zero, because there is no supply for the opamp without the output voltage. It's a matter of the chicken and the egg, who gets there first.

Jan Didden

[peranders]

Originally posted by janneman
Well, ALW will probably beat me to this (Hi Andy!) but believe me, in this designb EVERY (almost) component is tweaked, the reference, the opamp, the caps, the feedback circuitry, and yes, the bootstrapping of the opamp supply. Each giving measurable improvements and, as I have heard from other users, audible differences.

On top of that, the PCB layout has a MAJOR impact on the performance. A couple of wrongly routed traces can negate that expensive opamp or cap completely.

I think the Jung design is pretty much normal engineering science, no tweaking at all. There are better references for instance.

Also the pcb layout, normal Kirchoffs laws, and normal science, no voodoo like at >GHz.

[dipchip]

This is what the board size really looks like.
(at least on my 1280x1024 17" monitor)