| Super Regulator, collecting the facts - Click HERE for Original Thread |
| peranders |
Hi!
I wonder about a few things regarding the Jung Super Regulator:
How fast does it start with the original component values?
Does it work for negative voltage using AD797, assuming all signs have been changed, NPN->PNP and vice versa?
What happens when you have current limiting and the voltage is below min voltage for the opamp? |
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| PMA |
Per,
could you kindly link to the schematics?
Thanks,
Pavel |
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| dimitri |
| After building super regulator we connect it to several opamp via RC filters to prevent possible loops. The individual supply to each opamp will have source resistance R in parallel with C, now C value and it type again become significant. How should one choose R and C values? Should R be replaced by inductor? I feel that using super regulator for each opamp is too much. |
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| peranders |
jwb, you have a point here and I don't mind also good info collectors.
dimitri, I would have chosen 10-100 ohms + 47-470 uF// 100nF/63 polyster/ceramic. This I think is a good compromise for some isolation between the opamps. This is also good thinking.
Use 100 ohms to start with. Lower the value if you feel that you get to much voltage drops. Less than 10 ohms the isolation effect become rather small. |
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| dimitri |
| Peranders, as we use 10-100 ohms + 47-470 uF// 100nF (corner frequency 3-300Hz) why we need super regulator with milliohms in wide frequency range? We will lose the most of it strength. |
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| johnferrier |
Peranders,
Isn't the SuperRegulator idea incorporated into currently available low noise, low dropout regulators??? For example the LT1963 1.5 A regulator has less than 40uV noise (and the LT1763 0.5A regulator <20uV noise). A good voltage reference such as a REF02 has a typical noise of 4uV to start with.
LT1963 Datasheet:
http://www.linear.com/prod/datasheet.html?datasheet=886
Here is the TI datasheet: http://focus.ti.com/lit/ds/symlink/tps78601.pdf
Here is a good LT app note: http://www.linear.com/pdf/an83f.pdf
I've wondered about why people aren't using/talking about these.
(To be frank, my interest is to build a headphone amplifier so 1.5A is more than enough. For higher current capability, can't the LT1963 be used with a power FET?)
Comments anyone?
JF |
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| randytsuch |
Hi Guys,
I just bought a pair of kits from Andy, he sent them out this weekend, but they have to go from England to LA, so not sure when I will get them.
I plan to use them in a simple FET preamp, to generate the +/15VDC I need.
The original design called out for 3 term regulators, but I wanted to upgrade ;) .
I will let you guys know how it turns out, but as with all my projects, I am sure this one will take a while to complete.
Randy |
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| jwb |
Jung (and Sulzer, and other error-amp-with-pass-transistor designs) have extremely low output impedance and very wide bandwidth. The output impedance is much lower than three-terminal jobs like LT1962. That's why my headphone amp, with idle current only a few hundred milliamps, uses four Sulzer-type regulators instead of the commercial parts. The distortion reduction is significant.
What actually sold me on the Sulzer regulator was its amazing ability to regulate the load. Stepping from 0 to 1A output barely perturbs the voltage level. I was truly impressed.
Also three-terminal regulators tend to use noisier voltage references. In a superregulator you can use subsurface zeners or other high-quality refs. |
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| peranders |
| You have many good integrated regulators but this thread was about the Jung regulator in particular. The examples which you have mentioned is way over the 78xx/79xx but in some application nothing (at the moment!) beats a discrete regulator. |
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| peranders |
| quote: | Originally posted by jwb
Also three-terminal regulators tend to use noisier voltage references. In a superregulator you can use subsurface zeners or other high-quality refs. |
...and you can use any LP-filter you like to filter out the noise. |
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| johnferrier |
| quote: | Originally posted by jwb
Jung (and Sulzer, and other error-amp-with-pass-transistor designs) have extremely low output impedance and very wide bandwidth.
...
That's why my headphone amp, with idle current only a few hundred milliamps, uses four Sulzer-type regulators instead of the commercial parts. |
JWB,
Thanks, that is information I wasn't aware of and the feedback I looked for. (Sorry Peranders, at least I'm not on the IP tangent...)
Are you happy with your Aleph headphone amp design? Do you recommend this topology? Right now, I'm interested in a differential design and am wondering about SuperSymmetry. The leading candidate today is a pair of crosscoupled OPA637/discrete output buffers. I don't mind going to the effort of making one headphone amplifier, but I don't plan to wish I had constructed something else. (Like everyone, I would like to make The best that I can.)
I will reconsider the SuperRegulator idea based on your feedback.
JF |
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| grataku |
Going back to the subject matter I think the most refined Jung style SR at the moment is the ALW one. I am very intersted in the subject since I want to use it in my new, for personal use, preamp.
Unfortunately for reasons of PCB size and number of boards needed I need to design my own reg. |
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| fmak |
I've wondered about why people aren't using/talking about these.
(To be frank, my interest is to build a headphone amplifier so 1.5A is more than enough. For higher current capability, can't the LT1963 be used with a power FET?)
Comments anyone?
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I did , but no one was interested and went back to 20 yr old designs. I have been using these with good results.
Indeed the TI chips are good but they are spoilt by the need for a large ground plane to combat 50Hz noise. Why I don't know but all of that series is susceptable. They are also spoilt by the packaging not being a drop in replacement for 78xx. Neg regulators are also not extensive.
Perhaps more to the point is that 78xx and 79xx regs can be very good and much better than spec. Thre JRM ones especially so but one does need to select. The LT and LM series arev really not that good but look expensive! |
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| johnferrier |
| quote: | Originally posted by fmak
I've wondered about why people aren't using/talking about these.
(To be frank, my interest is to build a headphone amplifier so 1.5A is more than enough. For higher current capability, can't the LT1963 be used with a power FET?)
Comments anyone?
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I did , but no one was interested and went back to 20 yr old designs. I have been using these with good results.
Indeed the TI chips are good but they are spoilt by the need for a large ground plane to combat 50Hz noise. Why I don't know but all of that series is susceptable. They are also spoilt by the packaging not being a drop in replacement for 78xx. Neg regulators are also not extensive.
Perhaps more to the point is that 78xx and 79xx regs can be very good and much better than spec. Thre JRM ones especially so but one does need to select. The LT and LM series arev really not that good but look expensive! |
Combat 50hz noise:
LT1973--Low Noise: 40uVRMS (10Hz to 100kHz)
Neg regulator not extensive:
But positive regulators can be used as negative regulators, though with some degradation of performance.
The LT and LM series arev really not that good but look expensive!:
Though cheaper than discrete SuperRegulator circuitry.
If one wants a Jung-like SuperRegulator, take your favorite low noise, low PSRR, DC power amplifier circuit and bootstrap a reference voltage output to input. And use a pair of those to power the target amplifier circuitry. (Although I risk not making a lot of sense, I am trying to stay on topic.)
JF |
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| andy_c |
| quote: | Originally posted by peranders
(...)What happens when you have current limiting and the voltage is below min voltage for the opamp? |
Well, I think this can be determined by looking at the schematic. I think you're asking what would happen If one added current limiting to the circuit and it was enabled due, say, to a short at the output? From what I can see, it would be the following. The feedback would try to drive the pass transistor to as high a current as possible due to the shorted output. Maximum base current to the pass transistor occurs when the PNP emitter follower connected to the op-amp output is in cutoff, allowing all of the PNP current source's current to be delivered to the base of the pass transistor. Since the PNP emitter follower's emitter current would be zero, there would be zero volts across the zener and its series resistor. This would put the emitter of the PNP emitter follower at about +0.7 Volts. But the op-amp might only be able to swing within about 2 Volts from its negative rail (ground). So the base of the PNP emitter follower would be sitting at about 2 Volts. Looks like you'd end up with a reverse biased base-emitter junction of the PNP emitter follower, but not enough to break it down. There would also be a significant voltage difference across the differential inputs of the op-amp in this state, but if you've read ALW's site, you'll see that the diodes he puts across the differential input will protect against that.
The startup process is described in detail at ALW's site. |
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| jewilson |
There are regulators designs similar to the Jung-Sulzer-Didden around before their articles were published. If you have an old National Semiconductor application data books you will find regulators that look to be the foundation for this implementation.
While the implementation is different it may or may not be new for the time “it is still very well done” however I believe audio performance claims made in the articles for the circuit is new. The design offers great low noise performance and the ability to track dynamic changes in at the load with excellent stability. The keys are precision voltage reference, the high-speed transistor, the ultra low noise opamp, and the added ground sense implementation for audio.
My understanding is the only copyright protect belongs to the author work and what he is done in the development of the documentation for Audio Amateur-Audio Express magazine. They are no patents or trademarks other than the author name and no intellectual property issues.
To have intellectual property issues, as I understand it, this would have to have information i.e. a process, a method, or a design secret one has acquired at a company. Now, the person is at another company and if he implements the information gained at his previous employer that could be an intellectual issue. Therefore, the act of publishing the article for users, and users paying for the article seems to cancel out the intellectual property rights.
So using this circuit is ok for your home project. However, it would make good sense to alter and improve the design for commercial use. |
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| fmak |
[QUOTE]Originally posted by johnferrier
[B]
Combat 50hz noise:
LT1973--Low Noise: 40uVRMS (10Hz to 100kHz)
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If you try them out ( and I have) you will find that only the grounded tab models are free from 50Hz pickup. All others require ground planes which make their use a hassle. |
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| johnferrier |
| quote: | Originally posted by fmak
[QUOTE]Originally posted by johnferrier
[B]
Combat 50hz noise:
LT1973--Low Noise: 40uVRMS (10Hz to 100kHz)
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If you try them out ( and I have) you will find that only the grounded tab models are free from 50Hz pickup. All others require ground planes which make their use a hassle. |
I plan to give them a try. Here in the US, I'm sure that 50hz won't be a problem (obviously, 60hz might be a different story). Thanks for the info about the tab v no-tab.
JF |
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| Fred Dieckmann |
Despite my feelings that a circuit development for 20 years and with input from the readers was "public domain," Jan does not. I have to respect his feelings since he put a lot work into the project. I am very pleased that he approves the results of ALW who has put a tremendous amount of work into his design, that look to me to be real improvements. The Jung regulator was not typical most hobbyist magazine projects in terms of input from others and length of development. I view the work by Mr. Pass in a much different manner. It is the product of his work alone, and commercial copies compete in marketplace were he earns his living. He has weighed in on the issue of the Aleph PCBs and I will let him speak on that matter. I live in mortal of misrepresenting his feelings to even the smallest degree. The fact is that the Jung regulator was based very heavily on the Sulzer article, which addressed the issues important in regulator design in a very concise and straight forward manner. I think the original Sulzer article was one of the best pieces ever published in TAA and is the Rosetta Stone for audio regulator circuits. I like to reread it from time to time to see the forest in addition to examining the bark of one particle tree with a magnifying glass. It is a great overview and is still very relevant after 20 something years.
The AD797 is not a very good op amp for the circuit due to possible stability issues when used with remote sensing. I also believe its phase margin is not as good as several other op amps often used for this circuit. Some of the jfet input op amps seem to work very well in this circuit. I would not even use remote sensing, but put the regulator very close to the circuit it is providing the regulation for. Unless you are careful you can wind up with stability issues and noise pick up when using remote sensing. Line rejection, good transient response, and linearity seem to be more sonically important than lowest absolute output impedance or noise. The noise level has as much to do with the voltage reference, filtering of the reference, and the PCB layout, as the input noise of the op amp. |
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| ALW |
1. I didn't contact Walt before I did my PCB's, but did afterwards, primarily to say 'thank you', partly to ease my conscience (I actually had no intention of selling them, but was encouraged by popular demand).
Were I to do the same again I would ask for permission first, but since I do not make any significant income from the sale of these units (I value the feedback more than any financial gain) I felt less guilty - it's not a good excuse though!
2. As is mentioned on my website, Walt may not necessarily agree with all the component choices I made for that circuit either, certainly they are different from his original choices.
3. I think it's only polite to thank those that publish such circuits for their efforts, there's often considerable work put into such ventures that the reader may not be aware of.
My interest in the design was primarily that whilst widely recognised as offering great performance, the circuits seemed to be buried in the mists of time a bit. The constant clamour for information here, that was not served by any of the online resources I could find, swayed me to take a greater interest.
There was also a reputation for stability issues with the AD797 versions - these were addressed by Walt in his follow up 'Improved Regulator' article and in my experience the instability tag is no longer deserved.
There's an increasing number of commercial products starting to use what I strongly suspect is Walt's topology, with modification in many cases, but it seems to have taken some time for it to happen - companies such as Audiocom International who are marketing 'Super Regulators' or Trichord Research who are using Jung-type topologies in their phono stages.
I agree with Jan's comments - it's been very obvious to me, from the initial attempts by others to produce PCB's for the Jung reg's, that many seem to think that a 'PCB is simple'.
Design at this level requires serious attention to detail and Jan, like me, will have spent a long time developing that circuit board, I'm sure. Equally Walt will have expended great effort and time on the original circuit development, I am certain.
One can never assume that something doesn't matter, in audio, it often does.
Andy. |
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| johnferrier |
Beyond individuals here at diyaudio, how about a big company like Linear Technology that might incorporate the idea into a new component say the LT1963, sell it for half the cost of ALW's PCBA, and make serious money with the idea. Who knows what is going on inside their parts. It may be an exact copy of Jung's circuit. Who in the public knows? Necessary capacitance values noted in the datasheet. I'm not saying this is the case here, but I'm sure this has happened more than once.
We on topic peranders?
JF |
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| peranders |
Don't think so. First of all, you design different when you use silicone, many transistors, current mirrors, multi emitter transistors and other "weird" parts , very few caps, etc.
Much of the new thinking has taken place in the semiconductor factories just because you can design circuits which aren't possible in an another way. This is only what I think. |
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| Fred Dieckmann |
"I also wonder how long wires or pcb traces do you think is necessary in order to force use of sense wires? It's cool, but is it necessary if you talk AC performance and disregard a couple of uV is DC loss?"
The series resistance of the wires is added to the output impedance of the regulator. This is MORE OF AN ISSUE for AC than the DC drop because it affects the regulation of the voltage at the device drawing the AC current (i.e., music signal) . Remote sensing puts the wiring impedance inside the feedback loop so the regulator's low impedance appears at the load instead at the regulator output with the wiring impedance between the regulator and the load. Doing remote sensing with a regulator with a several tens of MHz GBW is very challenging engineering and beyond the scope of many analog designers. PCB layout is super critical. The error signals that the op amp in a well designed regulator is sensing in it's feedback loop are below the microvolt level. Without an absolute understanding of exactly where the signal currents run and where the feedback sense points are taken, a few millimeters of printed circuit board trace in the wrong place can greatly effect the regulation. Milliamps through Milliohms matter.
I think Andy is safe from any real competition in his design for a long time. Designing a very good regulator can be even harder than good amplifier or low noise preamp circuit. Most don't even know what the design problems are much less the solutions. This is real engineering with a vengeance at this level and why many find designing regulated supplies that sound good is a very frustrating task. Ever wonder why so many people use emitter followers and don't go very far beyond that for power supply regulators? |
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| peranders |
When "Sense"-inputs come up everyone talk how important it is what AC decoupling near the regulator in order to avoid unstability. Doesn't this apply here also?
Walter Jung from the EDN article.| quote: | | If you need remote sensing, you can add the remote-sense isolation resistor R2 at the load point. Breaking the normal sense line at X enables the remote-sensing option, with C1 added to decouple the sense loop at high frequencies. A negative-output version reverses the diodes and capacitors, along with the op-amp supply pins, and substitutes complementary transistors. |
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| jewilson |
Per,
It has more to do with the regulator tracking the load. The futher away the regulator is from the load the worse it tracks. Of course your right bypassing at the load is very important. |
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| peranders |
It has VERY much to do with load. If you have long wires you have also "L". What happens in an amp if you put an inductor at the output and then connect feedback after this L = oscillations if you are unlucky.
So, Jim you say also that AC wise it's no (or little) use with remote sensing because you short circuit the signal near the regulator. |
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| janneman |
| quote: | Originally posted by peranders
Don't think so. First of all, you design different when you use silicone, many transistors, current nmirrors, multi emitter transistors and other "weird" parts , very few caps, etc.
Much of the new thinking has taken place in the semiconductor factories just because you can design circuits which aren't possible in an another way. This is only what I think. |
I agree. There are things you can do in an IC that would be impossible in discrete form. And probably vice versa.
Jan Didden |
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| janneman |
| quote: | Originally posted by Fred Dieckmann
"I also wonder how long wires or pcb traces do you think is necessary in order to force use of sense wires? It's cool, but is it necessary if you talk AC performance and disregard a couple of uV is DC loss?"
The series resistance of the wires is added to the output impedance of the regulator. This is MORE OF AN ISSUE for AC than the DC drop because it affects the regulation of the voltage at the device drawing the AC current (i.e., music signal) . Remote sensing puts the wiring impedance inside the feedback loop so the regulator's low impedance appears at the load instead at the regulator output with the wiring impedance between the regulator and the load. Doing remote sensing with a regulator with a several tens of MHz GBW is very challenging engineering and beyond the scope of many analog designers. PCB layout is super critical. The error signals that the op amp in a well designed regulator is sensing in it's feedback loop are below the microvolt level. Without an absolute understanding of exactly where the signal currents run and where the feedback sense points are taken, a few millimeters of printed circuit board trace in the wrong place can greatly effect the regulation. Milliamps through Milliohms matter.
I think Andy is safe from any real competition in his design for a long time. Designing a very good regulator can be even harder than good amplifier or low noise preamp circuit. Most don't even know what the design problems are much less the solutions. This is real engineering with a vengeance at this level and why many find designing regulated supplies that sound good is a very frustrating task. Ever wonder why so many people use emitter followers and don't go very far beyond that for power supply regulators? |
Fred, I agree completely. I remember how challenging it is just to measure the Zout of this things. You need very carefull 4-wire impedance measuring techniques or you end up measuring the resistance of a piece of wire or PCB trace. I got some very nice flat traces of just 10 or 12 milliohms flat to 100kHz. Great supply? No. The supply had less than 1milliohms up til 20kHz, and rising. If you don't see the rising, you'r measuring the wrong thing, or you are a genius. I know I am not.
One of the initial problems we had to stabilise the supplies with 797's was due to remote sensing. The added inductance (and capacitance) inside the loop were just too much.
Jan Didden |
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| peranders |
Jan, if you don't pay attention to the coolness factor of remote sensing in this application, how important do you think it is really?
Note Fred, I still think Jan's and Andy's work is great. |
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| jcarr |
Jan:
>There used to be a big price advantage in production if you could stay with SS boards, even if you had to use tens of jumpers.<
Depends strongly on the local labor costs. In the 1970s and 1980s, the yen was cheap relative to the dollar, and wages were increasing but were not that high. In a situation like this, where labor costs are low, components that are cheap to make (like SS pcbs) will likely reduce the total cost of manufacture, even if the human labor content is comparatively high.
From around the middle 1980s, the value of the yen rose steeply, and so did Japanese wages. But the majority of Japanese audio products still relied on jumpered single-sided PCBs and complex wiring harnesses that looked like a ball of yarn after a cat had played with it. Even though the pcbs were themselves cheap, once the labor costs were added to the equation, the total cost of manufacture (and service and repair) was undoubtedly higher than if the designers would have opted for multi-layer pcbs.
It took some years for Japanese designers and management to get accustomed to new ways of doing things. Today, multilayer pcbs are quite common in Japanese audio equipment.
>There are things you can do in an IC that would be impossible in discrete form. And probably vice versa.<
Agreed, but I also think that there is a middle ground. By combining advanced transistors (like multi-gate FETs), multilayer pcbs, smd, three-dimensional construction techniques, it is possible to build circuits that, although may not quite match an IC for thermal tracking and complexity, do allow a lot of IC-style topologies and techniques (i.e., base-current compensation) to be used. Something along the lines of hybrid circuits.
regards, jonathan carr |
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| janneman |
| quote: | Originally posted by peranders
Jan, if you don't pay attention to the coolness factor of remote sensing in this application, how important do you think it is really?
Note Fred, I still think Jan's and Andy's work is great. |
Sorry, couldn't find "coolness factor" in my Oxford Dictionary. Other than that, the question really is, do you want to go to great length to make a very quiet and stable supply and then throw it overboard with too long, uncompensated wiring. The improvement with remote sensing is unquestionably, repeatably demonstrable, and not subtle in technical terms. Can you hear it? Depends on a lot of other things.
Or is your question: how important is superquiet and stable supply? I can't answer that question for you. I can't hear the difference between a BG or a Siemens cap, except in my wallet.
I have pleasure in trying to wring the last drop of performance from a circuit, knowing that it will make the resulting piece of equipment come closer to a straight-wire-with-gain. I may not be able to hear that last drop, but everyone has a turn-on. This is (one of) mine.
Jan Didden |
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| randytsuch |
Hi Andy,
I was going to email some questions to you, but since this thread is going, decided to post them here, might help someone else.
I am planning to use your Jung regulator, with the tracking pre regulator (LM317) to generate +/- 15VDC for my FET preamp.
I was planning on feeding it 21 VDC unregulated (15 VAC rectified).
First question is how much does it care about the unregulated VDC going in? I was thinking about getting a split core, over rated transformer (maybe 100 VA), and using Jensen 4 pole electrolytics in the rectifier circuit. Since the Jung is so good, can I use cheaper caps in the rectifier, and not notice a difference? Does the transformer make a difference?
How much decoupling can the target circuit have? I saw references to not exceed 100 uf decoupling caps, and not to exceed 1000 uf total capacitance.
I also need to know how to build a -15 VDC regulator, all the info in the manual seems to be for a +15 regulator (I think this question started the thread).
I was thinking about building separate regulators for left and right channels, but is that overkill? I would need 4 regulators then, seems like a lot, but I might do it if it improves the sound. Any comments? I will probably build it with two at first, and think about adding two more.
Also wondered how the regulators perform powering digital and clock circuits, generating 3.3 or 5 VDC. Would that be a good application for a Jung? I understand I would need a 2.5 V reference for this.
Thanks for any information you can provide. Hope this was not too many questions.
Randy |
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| peranders |
| quote: | Originally posted by randytsuch
First question is how much does it care about the unregulated VDC going in? I was thinking about getting a split core, over rated transformer (maybe 100 VA), and using Jensen 4 pole electrolytics in the rectifier circuit. Since the Jung is so good, can I use cheaper caps in the rectifier, and not notice a difference? Does the transformer make a difference?
How much decoupling can the target circuit have? I saw references to not exceed 100 uf decoupling caps, and not to exceed 1000 uf total capacitance.
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I leave the first question to the experts.. but a normal transformer will do and also normal caps but also allways you can do it more well done if you know what I mean? If it's a question of budget, you can start with simplier parts and then "upgrade".
About the capacitance at the output, some regulators can't take huge capacitance because the go into oscillations. It depends have the regulator is designed but if you can't measure it you can allways insert 1-100 ohms in series. With this you isolate the regulator from difficult load. The regulation gets a little bit worse but it's strongly dependent of the situation.
| quote: | Originally posted by randytsuch
I also need to know how to build a -15 VDC regulator, all the info in the manual seems to be for a +15 regulator (I think this question started the thread). |
Just change all polarized parts, transisitors (NPN->PNP), diods, caps and reference. Note also thatthe opamp allways gets negative voltage at pin 4 and positive at pin 7.
IMPORTANT: The opamp must be able to work (or at least start) at common mode voltage near positive rail. Far from everyone can do this. Just test or choose an rail-to-rail opamp.
| quote: | Originally posted by randytsuch
I was thinking about building separate regulators for left and right channels, but is that overkill? I would need 4 regulators then, seems like a lot, but I might do it if it improves the sound. Any comments? I will probably build it with two at first, and think about adding two more.
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Overkill, maybe but this is my trademark.... It's not bad to have a "serious" power but you can have more serious to chosen circuits.
| quote: | Originally posted by randytsuch
Also wondered how the regulators perform powering digital and clock circuits, generating 3.3 or 5 VDC. Would that be a good application for a Jung? I understand I would need a 2.5 V reference for this. |
For digital circuits you need low impedance at 1-500 MHz or so. The absolute value isn't very important. Serious decoupling is VERY impoprtant. Also proper grounding. |
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| peranders |
| quote: | Originally posted by randytsuch
I was planning on feeding it 21 VDC unregulated (15 VAC rectified).
First question is how much does it care about the unregulated VDC going in? I was thinking about getting a split core, over rated transformer (maybe 100 VA), and using Jensen 4 pole electrolytics in the rectifier circuit. Since the Jung is so good, can I use cheaper caps in the rectifier, and not notice a difference? Does the transformer make a difference?
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Instead of a pre regulator you can also do as I have done. Put small resistors after the recifier and to get even more filtering use an another RC- filter. I have a R-C-R-C filter in order to get smooth voltage. This is a passive solution so you must have control over the max load. An active pre regulator is more flexible if you have varying (spelling?) loads. |
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| Fred Dieckmann |
If only the rest of the questions as well....
'you can allways insert 1-100 ohms in series. With this you isolate the regulator from difficult load. The regulation gets a little bit worse but it's strongly dependent of the situation."
At low frequencies, several orders of magnitude. That is the first time that I have seen differences of thousands of times higher described as "a little bit worse"
"Just change all polarized parts, transisitors (NPN->PNP), diods, caps and reference. Note also thatthe opamp allways gets negative voltage at pin 4 and positive at pin 7."
NO! Besides too being vague for useful advice for anyone who doesn't understand to a degree that would make it unnecessary to ask the question, it is wrong. The circuits are different enough to require different PCBs for the negative and positive regulators. The circuits are similar and require PNP-NPN and capacitor polarity differences, but the circuit topologies are different as well and require a different schematic and PCB layout for positive and negative versions.
"IMPORTANT: The opamp must be able to work (or at least start) at common mode voltage near positive rail. Far from everyone can do this. Just test or choose an rail-to-rail opamp."
Please explain this one. After reading about the development of this circuit for several years I have never seen this claim made. The bootstrap circuit for startup forces the voltage within the common mode range while the circuit is powering up. the circuit has been used with a variety of op amps. One of the most popular has a common mode input range 1.5 V below the supply voltage at the op amps power pins which is hardly a rail to rail op amp.
I hope my fellow forum member Pan'andlers (I let you call me Phred...) will address these concerns regarding his advice. |
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| peranders |
| quote: | Originally posted by Fred Dieckmann
If only the rest of the questions as well....
'you can allways insert 1-100 ohms in series. With this you isolate the regulator from difficult load. The regulation gets a little bit worse but it's strongly dependent of the situation."
At low frequencies, several orders of magnitude. That is the first time that I have seen differences of thousands of times higher described as "a little bit worse"
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Fred, you know perfectly well that it is the high frequencies that are important and also more difficult for the regulators. A couple of millivolts in ripple, hum isn't especially harmful in front of a Jung regulator or any for that matter. We talk about raw voltage fed to a regulator so thousand times better than what.... at the output? Fred, I don't say it's wrong to use a pre regulator, just that there might be other solutions not that bad.| quote: | Originally posted by Fred Dieckmann
"Just change all polarized parts, transisitors (NPN->PNP), diods, caps and reference. Note also thatthe opamp allways gets negative voltage at pin 4 and positive at pin 7."
NO! Besides too being vague for useful advice for anyone who doesn't understand to a degree that would make it unnecessary to ask the question, it is wrong. The circuits are different enough to require different PCBs for the negative and positive regulators. The circuits are similar and require PNP-NPN and capacitor polarity differences, but the circuit topologies are different as well and require a different schematic and PCB layout for positive and negative versions. |
I don't know about Andy's pcb (haven't checked close enough) but As I see only the opamp must have it's pin 7 and 4 swapped (requires a litlle bit patching) otherwise I don't know what mean. | quote: | Originally posted by Fred Dieckmann
"IMPORTANT: The opamp must be able to work (or at least start) at common mode voltage near positive rail. Far from everyone can do this. Just test or choose an rail-to-rail opamp."
Please explain this one. After reading about the development of this circuit for several years I have never seen this claim made. The bootstrap circuit for startup forces the voltage within the common mode range while the circuit is powering up. the circuit has been used with a variety of op amps. One of the most popular has a common mode input range 1.5 V below the supply voltage at the op amps power pins which is hardly a rail to rail op amp. |
Fred, some opamps have "properties" if they are used outside the common mode limits. If it's good or bad you can't tell until you have tested the type. One thing to remember also is that different brands of the same type can behave differently.
I don't say this is a big problem but you should be aware of it. |
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| janneman |
| quote: | Originally posted by peranders
I leave the first question to the experts.. but a normal transformer will do and also normal caps but also allways you can do it more well done if you know what I mean? If it's a question of budget, you can start with simplier parts and then "upgrade".
JANNEMAN: A split core transformer has the HUGE advantage that it attenuates mains noise, spit, pople and crach much, much better then toroids. Using toroids for preamps is unneccesarily compromising on quality.
About the capacitance at the output, some regulators can't take huge capacitance because the go into oscillations. It depends have the regulator is designed but if you can't measure it you can allways insert 1-100 ohms in series. With this you isolate the regulator from difficult load. The regulation gets a little bit worse but it's strongly dependent of the situation.
JANNEMAN: This is utter BS. It's actually the intermediate (10-100uF) that may give oscillations. Increasing the cap normally turns it off again.
JANNEMAN: 100 Ohms in series? A little worse? You really have no clue where you talk about, do you? You read somewhere that opamps with cap load need an output resistor to be stable and you port that to regulators without the slightest thinking. I will not insult the others on this forum by explaining why this is a no-no.[snip] |
Jan Didden |
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| grataku |
| quote: | Originally posted by Fred Dieckmann
"Just change all polarized parts, transisitors (NPN->PNP), diods, caps and reference. Note also thatthe opamp allways gets negative voltage at pin 4 and positive at pin 7."
NO! Besides too being vague for useful advice for anyone who doesn't understand to a degree that would make it unnecessary to ask the question, it is wrong. The circuits are different enough to require different PCBs for the negative and positive regulators. The circuits are similar and require PNP-NPN and capacitor polarity differences, but the circuit topologies are different as well and require a different schematic and PCB layout for positive and negative versions.
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I have Jan article in front of me and the PCBs for the + and - look close enough.
I would be very interested in knowing how many iterations the ALW pcb required.
IMO, the the bandwidth is low enough to be pretty forgiving. |
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| Fred Dieckmann |
"I have Jan article in front of me and the PCBs for the + and - look close enough.
I would be very interested in knowing how many iterations the ALW pcb required. IMO, the the bandwidth is low enough to be pretty forgiving."
Then why go though the time consuming task of laying out two different PCBs for the negative and positive regulator? Would someone actually look at a schematics and stop shooting from the hip. They are similar
but not identical. I think a board could be designed for both options but compromise for the op amp PS terminals would very likely compromise the design. I am sorry that this circuit looks so easy to a lot of you, but the PCB layout is critical to a state of the art power supply design like this. The bandwidth of the op amp is pretty high and the understanding of all the voltage drops in the layout for the correct location of the sense points is very demanding. There are any number of ways that the performance can be compromised by even small layout changes from the optimum. I just don't know why this is unclear. We're talking about signals and trace resistences SIGNIFICANTLY BELOW the microvolt, milliamp, and milliohm level.
Another real factor is that offering a kit with complicated stuffing options is a disaster waiting to happen with people unfamiliar the design, even with excellent documentation. A board with a silkscreen useful for both? I can't even imagine, and I have designed PCBs with stuffing options much simpler that have still confused people despite my best efforts. |
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| peranders |
| quote: | Originally posted by Fred Dieckmann
Another real factor is that offering a kit with complicated stuffing options is a disaster waiting to happen with people unfamiliar the design, even with excellent documentation. A board with a silkscreen useful for both? I can't even imagine, and I have designed PCBs with stuffing options much simpler that have still confused people despite my best efforts. |
Fred, DIY'ers aren't illiterates and/or fools. Most of them can read and also understand what problem or task is.
There is normally no problems at all with alternative parts, or placements.I see no trouble at all with a universal pcb both for positive and negative supply. Since the opamp has flipped pins you can simple have "two" opamps on the pcb if you don't want to use jumper wires. |
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| peranders |
| quote: | Originally posted by janneman
Do it anyway, Elso! This is DIY, right? We do it for free anyway. And seeing your name is print is a real kicker! So, the money is like a nice touch. I would have done it for free.
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Me too also, if I could use my stuff freely which is impossible if you work for Elektor. If I have understood the Elektor contract right, it's not a very good deal except that your name might be known. |
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| grataku |
| quote: | Originally posted by Fred Dieckmann
We're talking about signals and trace resistences SIGNIFICANTLY BELOW the microvolt, milliamp, and milliohm level.
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If you are interested I am going to tell you what I do, in private, suffice it to say I am working at 750MHz, pulsing 100's of watts and getting back microvolts, I am sure you would find it fascinating.
At that frequency a 1mm X 1mm Cu strip inductance and resistance makes a 5 MHz difference in tuning and 20 ohm difference in matching, but that doesn't matter.
In the case of the superreg I don't think things are _that_ critical.
That's all I am saying. From reading ALW manual it actually seems that Q damping is required in some instance. |
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| peranders |
| When I think about it, is it really smart to have the AC gain set to one? I mean a little bit lower noise which is extremely low already and then risk problems with unstability? |
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| Fred Dieckmann |
"If you are interested I am going to tell you what I do"
In absolute seriousness, compared to that I am sure almost every circuit looks simple......
I can only point out that 1 ma through 1 milliohm is one microvolt. A preamp circuit driving 1V into 10K ohms results in a current of 100 microamps, and this at the higher signal levels seen by a preamp. The music signal has dynamic range exceeding 80 dB. The bottom line is that a power supply, such as the Jung type design, involves consideration of error signals in the nanovolt (10 to the-9th) region. This would seem to me to be some very rigorous engineering when pushing the state of the art for an audio power supply design like this. Plenty challenging for me and most of the others of the forum, even the serious analog engineers I'd imagine. The evolution this circuit from the original Sulzer circuit has been documented for over 20 years in The Audio Amateur and Audio Electronics. Enhancements for the circuit are still being pursued at present. I can think of at least half a dozen changes worth investigating and I am sure there are many others that I haven't thought of, but others have. I am still curious how much further this design can go in terms of improvement. |
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| peranders |
| Fred, have you thought about writing texts for ads? ;) |
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| Fred Dieckmann |
| quote: | Originally posted by peranders
When I think about it, is it really smart to have the AC gain set to one? I mean a little bit lower noise which is extremely low already and then risk problems with unstability? |
Stability still has to be considered at AC gains above one. Half the AC closed loop gain; halves the noise and output impedance. A third year Electical Engineering student or a long time reader of The Audio Amateur should know this I think. |
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| Fred Dieckmann |
| quote: | Originally posted by peranders
Fred, have you thought about writing texts for ads? ;) |
I have done it for my audio products in the past. |
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| peranders |
| quote: | Originally posted by Fred Dieckmann
Stability still has to be considered at AC gains above one. Half the AC closed loop gain; halves the noise and output impedance. A third year Electical Engineering student or a long time reader of The Audio Amateur should know this I think. |
We are nice today.
I mean , AD797, gain of one, not short wires. |
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| Fred Dieckmann |
"There is normally no problems at all with alternative parts, or placements.I see no trouble at all with a universal pcb both for positive and negative supply. Since the opamp has flipped pins you can simple have "two" opamps on the pcb if you don't want to use jumper wires."
Great idea! I am sure we will see this on your knock off version on the circuit. Charge enough for the PCBs to compensate yourself for the time you will spend on people who blow it up building it wrong. I think you can count on it quite often.
"I mean , AD797, gain of one, not short wires."
So do I ....... |
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| peranders |
As I said before DIY'ers have something inside their heads and they usually use it. That my experience. Please give the big crowd DIY'ers credit, Fred.
Fred, have you never made a pcb for multi purpose? Mostly rather easy. |
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| Fred Dieckmann |
| I am not saying DIYs are not smart enough to build a kit. For PCBs this simlar with this many stuffing changes between the versions will make it more difficult for many to assemble, most people being unfamiliar with the design. It is the intellegence and responsibility of the person offering the kit and not that of the one purchasing it that is under discussion. Why make it more difficult for the person buying the board instead of doing the work for two versions which require small changes between the layouts? |
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| peranders |
| quote: | Originally posted by Fred Dieckmann
Why make it more difficult for the person buying the board instead of doing the work for two versions which require small changes between the layouts? |
I think you know the answer if you ordered one, two or even more different series of pcb's. |
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| Christer |
There seem to be reasonable arguments both for one PCB and
for two separate ones, but wouldn't perhaps the most obvious
solution be one PCB with two regulators, one pos. and one neg.?
I mean, most people will probably want both anyway and it
would seem attractive to minimize the board count in a design.
Back to an earlier issue in the thread, does anybody have a
good answer to dimitris question (post #26) on how to feed
multiple ICs from one regulator. I share the same concerns as
dimitri regarging Per-Anders answer to the question, so other
opinions would be welcome. |
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| peranders |
| quote: | Originally posted by dimitri
Peranders, as we use 10-100 ohms + 47-470 uF// 100nF (corner frequency 3-300Hz) why we need super regulator with milliohms in wide frequency range? We will lose the most of it strength. |
A One regulator for each IC
B One regulator for all IC and all IC's connected low-ohmish together
C One regulator for all IC but all IC's separated with
C1 R+C
C2 L+C
C3 Murata-filter plus C
C4 L+R+C
C5 ?????
What do the experts say?
If anyone suggests C, why do we need this regulator? Good point Dimitri.
How many amps have PS which delivers less then 1 uV noise?
Have many amps MUST have power with less noise than 1 uV in order produce high fidelity?
How many people think it's cool to have a super regulator? |
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| peranders |
| quote: | Originally posted by Christer
There seem to be reasonable arguments both for one PCB and
for two separate ones, but wouldn't perhaps the most obvious
solution be one PCB with two regulators, one pos. and one neg.?
I mean, most people will probably want both anyway and it
would seem attractive to minimize the board count in a design. |
Nothing stops Andy to make them pos, neg in the same board except for that the cooling arrangement must be different. |
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| Fred Dieckmann |
"Nothing stops Andy to make them pos, neg in the same board except for that the cooling arrangement must be different."
I think you had better ask Andy about his layout and Jan Didden about his layout for the Jung regulator. I really think you don't have any experience with the circuit and are very likely unqualified to make that judgment. I am constantly amazed that someone thinks they can look at a circuit for few hours and know more than people who have been working with the circuit for years. There a very few on the forum who are that sharp, I'm sure not one of them. My views on the circuit are based on following the design since the Sulzer original in 1980. Does anyone know what "delusions of grandeur" is in Svensk ? Is "storhetsvansinne" close? |
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| randytsuch |
Hi guys.
First, want to try to clear something up.
Andy IS making a positive and negative version of the Jung regulator. He appears to have two different PWB's.
The misunderstanding came from my stupidity :xeye:, I missed it in the user's manual. It was really that I was careless, and I have no excuse for it.
Very sorry for any and all confusion I caused here.
Secondly, thanks to all for the answers/replies to my questions. I had not idea they would be a cause of controversy, but I really appreciate the time people took to answer me.
As for my project, Andy is sending me a positive and negative version of his kit, so I will build each one up, and use it to power my preamp. I might make another pair in the future, so I can go dual mono.
I will go with a split core tranny, and probably use Nichicons for the PS filter caps, and freds for the bridge diodes. Budget is of some concern, but time is a bigger issue for me. I would rather spend a little more up front, so I won't have to tweak it latter to try to make it better.
I am still not sure how much filter capacitance to put in my preamp, but I have a scope, so I can play with that, and see if I get any oscillation.
Thanks/sorry,
Randy |
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| dimitri |
Dear Christer and Peranders,
This is how I test regulator dynamic behavior from the output side during last 20 years. May I recommend you to do the same with any regulator, starting from three transistors types to precision one. You will be astonished and will forget about dc uV and use Peranders C. |
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| janneman |
| quote: | Originally posted by dimitri
Dear Christer and Peranders,
This is how I test regulator dynamic behavior from the output side during last 20 years. May I recommend you to do the same with any regulator, starting from three transistors types to precision one. You will be astonished and will forget about dc uV and use Peranders C. |
Of course you are astonished. You thought you were measuring the regulator, but in effect you have been checking the dynamic impedance of a cap with parallel inductance with DC offset. 20 years you said?
Jan Didden |
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| peranders |
| Jan, what do you say about the "best" method in distributing power, tied together or some isolation? |
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| peranders |
| quote: | Originally posted by janneman
Of course you are astonished. You thought you were measuring the regulator, but in effect you have been checking the dynamic impedance of a cap with parallel inductance with DC offset. 20 years you said? |
We are nice..... :no:
This is a perfectly good method if you are interested in the lower frequencies. Inductance of a short wire is nothing (OK, not much) at 100 Hz, 1 kHz or so but you should allways be carefull in analyzing results. What are you measuring really. Never hurts to think about it.
If you are testing a high speed regulator, the test setup is a little bit more advanced, right Fred? |
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| Christer |
| quote: | Originally posted by Fred Dieckmann
Does anyone know what "delusions of grandeur" is in Svensk ? Is "storhetsvansinne" close? |
Not only close, it is correct. Where on earth did you dig that
up? Don't tell me you are studying swedish in secret. ;) |
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| Jocko Homo |
Unless you look in the "newer op-amps" thread.
Between watching Phred and Per pulling each other's leg, John Curl stating what a lot of us have known for years (which seems to baffle others), Jan trying to keep his sanity while looking at bogus measurements, and the mystery of Babel to compound it all.............
Yep, I love this place.
Back to our regular entertainment.
Jocko |
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| Fred Dieckmann |
"Not only close, it is correct. Where on earth did you dig that up? Don't tell me you are studying swedish in secret."
No..... actually I am studying Swedes in public. |
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| Christer |
| quote: | Originally posted by Fred Dieckmann
[BNo..... actually I am studying Swedes in public. [/B] |
I see. On this forum presumably. :) |
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| dimitri |
Dear Jan,
“You thought you were measuring the regulator, but in effect you have been checking the dynamic impedance of a cap with parallel inductance with DC offset.”
No, I am measuring the regulator in practical setup. Would you measure audio amp with resistive load or nevertheless with real speaker?
“I have pleasure in trying to wring the last drop of performance from a circuit” Please be aware there are a lot of bottles in the cellar still… |
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| janneman |
Dimitri,
I don't understand your answer. You are measuring the supply after 50cm of wiring. As I said, you reaslly measure the cap and the inductance of the wire, which appears in parallel with the cap. Whatever you measure doesn't say a lot about the quality of the supply. So, you'r not really measuring the supply. Don't take it personally.
This is apart from the fact that connecting a supply with 50cm of wire means you lose any high quality regulation that you could get from a Jung-type regulator. A standard 7815 is cheaper, easier and gives the same results.
Jan Didden |
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| peranders |
Jan is right. Dimitri, you must establish where the regulator "ends" and where your test gear starts. I don't consider 50 cm wire as part of a regulator.
But once again it depends what you are really interested in to measure. |
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| dimitri |
Let us consider typical preamp (mixer, RIAA, mic). We try to place active circuit board as near as possible near the input jacks, we even make gain control spindle longer. We try to place xformer with rectifier, caps and regulator as far as possible from the input jacks. What will be the length for dc supply wires, including pcb conductors? Ok, don’t like 50cm, ok, 20 cm. Somebody in this thread speak about square mm of pcb conductor and uV. How can we compensate wires – by 4 wire circuit, but what will be when we try to feed
multiple ICs? We don’t need ultimate parameters for two specific nodes on the regulator output, we need good parameters for the whole supply rail.
I personally use 4 wire circuit for the output op-amp, because I have now idea what it load will be. Other op-amps feed through RC filters, but I try to switch their output stage in class A (or to use op-amp with appropriate quiescent current). When I don’t have cost restriction I use precision regulator with normal bipolar output stage (not the single follower) operating in class A with quiescent current value higher, than will flow in the circuitry. |
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| jwb |
| GOsh, that seems sort of odd. I try to put the regulator adjacent to the regulated circuit, not 20 or 50cm away. |
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| Jocko Homo |
I'm not gonna touch this one.............
Jocko |
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| peranders |
The thread just died when Dimitri and I asked this.
Not even Fred has a practical suggestion :scratch:
If the pcb is 200 mm or more AND there are several power consumers and we don't want (or can afford, space money cost) one regulator to each opamp or whatever.
Can Jan or anyone else suggest and practical solution?
My personal choice would be R+C. |
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| janneman |
| quote: | Originally posted by dimitri
Let us consider typical preamp (mixer, RIAA, mic). We try to place active circuit board as near as possible near the input jacks, we even make gain control spindle longer. We try to place xformer with rectifier, caps and regulator as far as possible from the input jacks. What will be the length for dc supply wires, including pcb conductors? Ok, don’t like 50cm, ok, 20 cm. Somebody in this thread speak about square mm of pcb conductor and uV. How can we compensate wires – by 4 wire circuit, but what will be when we try to feed
multiple ICs? We don’t need ultimate parameters for two specific nodes on the regulator output, we need good parameters for the whole supply rail.
I personally use 4 wire circuit for the output op-amp, because I have now idea what it load will be. Other op-amps feed through RC filters, but I try to switch their output stage in class A (or to use op-amp with appropriate quiescent current). When I don’t have cost restriction I use precision regulator with normal bipolar output stage (not the single follower) operating in class A with quiescent current value higher, than will flow in the circuitry. |
Dimitri,
That's all fine and dandy, but the fact remains that you claimed to measure regulator performance where you actually didn't.
Now, to your post: Indeed, take the typical RIAA etc. One stage, two stages? How close are the supply points of those two stages? 1/2 inch apart? How close can you place the regulators? Anothe 1/2 inch away? Total 25.4 mm give or take a few angstrom. A far cry from 500 or 200 mm.
And come on, give me a break. We didn't talk about how far the xformer was away. As far as I am concerned, that can be in the next room. We were talking about the regulator distance.
But, apart from being a story that isn't holding water, it also has no bearing on the original issue. You'll have to do better than that.
Anyway, I'm sure you know the score. I'm not going to spend any more time on this thread explaining the obvious. You have the last word.
Or maybe Per-Anders
Jan Didden |
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| Fred Dieckmann |
"we need good parameters for the whole supply rail."
Power distribution is the same principle as single point grounding. The first thing is to determine which circuits are the most sensitive to power supply noise and put them close to the central hub of single point ground and power supply plus and minus voltage outputs with short traces. Segregate large power supply signal currents from sharing common traces with sensitive low current signals. Using separate power supply traces to each device when possible is a very good idea. It keeps signal currents from sharing a common trace impedance, which creates an error voltage that is common to both devices, and is a function of both devices power supply currents. This from their separate signal currents across a common trace impedance. Designing for low crosstalk from currents is the key. Think of the voltages at each device's supply terminals in terms of signal currents and the trace resistances through which the currents travel from the point of low impedance output of the supply. RC filters are effective at filtering noise from the central supply but are real compromise since signal currents through series resistors will cause variations in voltage at the device drawing the signal currents. The biggest mistake is not understanding the supply currents to each device's supply terminals, and failing to plan the ground and supply path before the rest of the audio circuit's placement. The circuit should be built around the power supply distribution early in the layout process. You cannot go add the power distribution afterwards. This sounds a little abstract and you need apply it to the particular circuit you are designing.
A couple of good references are:
http://www.analog.com/UploadedFiles...08865AN-202.pdf
POWER UP:
An Overview of Power Supply Considerations
R.N. Marsh The Audio Amateur 3/83 |
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| Christer |
Thanks, Fred, that makes perfect sense to me. Don't know why
anybody would find it abstract though? |
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| jwb |
Because grounding is hard. Sometimes you won't even realize the problem until you've built the prototype and measured it. How best to wire power rails and grounds? When is a ground plane good and when is it a disaster? etc.
That, and the members of this board are generally unable to apply Kirchoff's Law. |
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| jcarr |
Nice post, Fred.
Very similar approach to how I design pcbs and harnesses. As much as possible (when it makes sense), I feed each block of amplifier circuitry from its own regulator. When this isn't feasible, I get rid of every shard of common impedance that I can ferret out. And when separate regulation is feasible, I still do the same.
regards, jonathan carr
PS. I normally keep each regulator no more than about 8mm away from its load, and I also use local bypasses (lots of 'em). |
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| Fred Dieckmann |
It can be just that. I did a two layer line card. (low cost! 4 layers with ground plane would have got me fired) The grounding required digital, analog, transient (10s of amps), RFI and ESD grounding. The only thing missing was coffee grounds.
The grounding strategy could not quite be single point ground and had to share some common traces. I spent a long time thinking very hard about return current path, in order to avoid my boss having grounds to fire me. I never have pulled it off if I wasn't doing it with the best PCB designer I will ever get to work with. He could tell what I wanted, even when I couldn't quite explain it while sitting next to next to him in front of the monitor. You will never see me that grateful again for someone that talented to work with. |
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| peranders |
It's allways a pleasure to let pros do the work for you. My "pro" is a toolmaker for plastic molding. He knows molding tools which I don't.
Fred, may I ask what the pcb did? The application? |
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| peranders |
Fred, I have now educated myself, since I don't know so much... I have only the Sulzer article left which I'm getting from someone here.
The 100 uF in the feedback, is this only to decrease the noise about 6 dB (at the expense of stability) or is it something else? |
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| janneman |
| quote: | Originally posted by Christer
Per-Anders,
not that I really know, but isn't the cap there to improve load
regulation by giving 100% feedback for AC? |
Indeed. And since it increases feedback (AC) to 100%, it has an impact on the transfer characteristic. It generally, in this kind of circuits, but not always, decreases stability.
Jan Didden |
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| peranders |
| quote: | Originally posted by janneman
Indeed. And since it increases feedback (AC) to 100%, it has an impact on the transfer characteristic. It generally, in this kind of circuits, but not always, decreases stability. |
Was the only reason to have this 100uF to decraese the output impedance by 2 and a speed increase of factor 2? |
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| peranders |
| quote: | Originally posted by janneman
Per, basically you are right, but I find more content in those posts then in your last one...;) |
Yeah, I noticed it but I couldn't help it. :cannotbe:
BTW: I have read the Sulzer article from 1980, (thanks Elso, I made a pdf of it) and I get a bit nostalgic. 23 years ago is a long time.... He talks about 741, anyone who remembers this opamp?
Walter Jung points out that he wasn't the "inventor" of the regulator neither Mr Sulzer. Does anybode know when the "Sulzer regulator" was seen first? Was it in the tube era? |
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| SY |
| quote: | | Those other mods obvously haven't been cracking the whip enough whilst I was gone... |
I would, but I've been playing Roy Horn elsewhere. And all the regulators discussed here are silly-low in voltage. He-men like me, the kind that have Britneys and Swedish Bikini babes hanging on their arms getting in the way of my soldering, use 500V regs at a minimum. The design requirements are a bit different at those levels.
As for the "inventor" of opamp voltage regulators, I can't say, but they certainly exisited in chip form for a long time before the Sulzer articles. My 1978 NS databooks show quite a few, and no doubt the concept dates back to the tube-only era. |
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| topicreader |
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Thank you and best regards: George |
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| janneman |
| quote: | Originally posted by SY
[snip]As for the "inventor" of opamp voltage regulators, I can't say, but they certainly exisited in chip form for a long time before the Sulzer articles. My 1978 NS databooks show quite a few, and no doubt the concept dates back to the tube-only era. |
Certainly pre-war (2nd world war, that is). Probably just after the invention of neg feedback by Harry Black in the late 30-ies.
Jan Didden |
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| peranders |
I'll guess that the most important facts are lifted up and the conclusion is that the "Jung Super Regulator" as it has been called is a good solution of a low noise regulator.
I'll appreciate the efforts from Jan Didden, Elso, Brian, Nicke from Sweden and the rest of you which have contributed in getting me the articles of Jung and Sulzer and other valuable info. |
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| john curl |
| I personally don't use the Jung 'super-regulator' in any of my products, but I respect everything that Walt does in this area. Look for more, in future. However, it is very important to make the best AC-DC filtering system possible, in order that the regulator is taken out of the sonic imprint. Trust me, it is NOT easy, except with batteries. |
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| john curl |
| If it was up to me to 'improve' this regulator, I would try to use a video IC for the gain. This would give, all else being equal, faster response, more linear feedback control, and about the same noise. |
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| peranders |
| Good idea but what about the transistors speed? Doesn't the pass transitor be really fast also? |
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| PRR |
I still think of the 741 as "new". I worked with 709s. Great little amps; just don't short them.
I have and sometimes use a mixer with all 301 opamps. The 301 is a 741 with external compensation. Decompensated to Gv=10, it gets pretty good slew rate and bandwidth. Noise isn't all that bad, if you use high-ratio mike transformers. And you can short a 741/301 all day long, what a blessing!
IMHO, there is no single novel thing in the Jung Reg. All of it had been done decades before, and I'm sure he would be the first to say so. What he DID do was put together and publish a practical topology and values that does about as good as possible for just a few dollars.
> What happens when you have current limiting and the voltage is below min voltage for the opamp?
The linked schematic has no current limiting, unless I'm missing something.
If the voltage is too low for the op-amp, often it is too low for whatever you are powering. For a first approximation, you don't care what happens. But in a refined design, you better check the "brown-out" behavior does not make nasty pops and squeals that might blow up somebody's favorite amp or speaker. |
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| Jocko Homo |
Apparently, someone in Sweden still does. I recently did some consulting in regards to a product out of Sweden.
Somehow.......not only did they manage to use 741s, they found them in a SMD package! I can't imagine that there are enough people who still use that log to justify making it in SMD.
Yeah, you guys in Sweden really don't get out much.
Jocko |
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| BrianGT |
For the lab classes here at school, they mostly use the 741, and sometimes the 351. The 351 measures much better, but isn't as stable.
I guess it is one of the cheapest general purpose opamps that you can get.
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Brian |
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| Da5id4Vz |
My recollection of the 741 is that its something of the Swiss Army op-amp, not the quietist thing in the world, but you could design all kinds of stuff around it.
Kind of like having a pocket full of 2n222. |
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| andy_c |
| quote: | Originally posted by peranders
Good idea but what about the transistors speed? Doesn't the pass transitor be really fast also? |
Per-Anders,
Why not try a simulation of the circuit using LTSpice? It's pretty easy to bring in the Analog Devices op-amp models, and they do a good job of modeling all the poles and zeros of the transfer function, as well as many other things. See http://www.analog.com/UploadedFiles...801016AN138.pdf for more details. For my simulation, I used the MJE15030 for the pass transistor. Note that the simulated ft vs current of this model matches very well with the data sheet curves (see http://www.diyaudio.com/forums/show...5533#post245533 You'll find that it won't be stable if you assume the 100uF load is an ideal capacitor. To fix this, you can go to ALW's site and find the vendor of the capacitor. Then go to that vendor's web site where you'll find curves of impedance vs. frequency which should allow you to get a good approximation of the capacitor model. I'd be glad to help, but only if you put forth the effort to set everything up first. |
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| peranders |
| quote: | Originally posted by Jocko Homo
Apparently, someone in Sweden still does. I recently did some consulting in regards to a product out of Sweden.
Somehow.......not only did they manage to use 741s, they found them in a SMD package! I can't imagine that there are enough people who still use that log to justify making it in SMD.
Yeah, you guys in Sweden really don't get out much. |
I know that 741 is still around but why would you choose this opamp if it was for new design? OK if it was to be replaced only in an excisting circuit but otherwise? |
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| peranders |
| quote: | Originally posted by PRR
IMHO, there is no single novel thing in the Jung Reg. All of it had been done decades before, and I'm sure he would be the first to say so. What he DID do was put together and publish a practical topology and values that does about as good as possible for just a few dollars. |
Walt Jung points out that he isn't the inventor of the circuit. |
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| janneman |
| quote: | Originally posted by john curl
If it was up to me to 'improve' this regulator, I would try to use a video IC for the gain. This would give, all else being equal, faster response, more linear feedback control, and about the same noise. |
John,
I am sure that is the way to go. Not only for regulators, also in other audio-related applications. For one thing, you get low THD not just at 1kHz but out to 100kHz.
However, I would hesitate to give the details about this next revolution in audio to Per.
Jan Didden |
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| Elso Kwak |
| quote: | Originally posted by janneman
John,
I am sure that is the way to go. Not only for regulators, also in other audio-related applications. For one thing, you get low THD not just at 1kHz but out to 100kHz.
However, I would hesitate to give the details about this next revolution in audio to Per.
Jan Didden |
Hi Jan and John,
Faster is better? I doubt it! But the current trend is like that. I tried some pretty fast opamps like AD817. Not my piece of cake.
Per-Anders what are the real motives to start this thread? Collecting facts? Then you have only to copy articles from the net and the Audio Amateur journal. Your QSXPS on your site is in fact a Jung like regulator with a Darlington pass transistor and a LM431 as the reference. |
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