Simple Super Shunt and Simple Super Shunt w/CCS vs. JSR03/05 (and other series regs)

[hollowman]

In the Feb 2008 issue of AudioXpress (US print magazine) pp. 30-37, the article "Shunt or Not" by author Are Waagbo presents two "sophisticated shunt regulator version[s]":





The author claims that in comparison to his shunts, the JSR03/05 was “a waste of money” (noting a simple zener shunt was better). He also indicates other series-regulator designs (e.g., Borbely and Sulzer) are not much better.

Along with his own, Waagbo does credit Borbely’s shunt regs.

What do you folks think? Can a simple Zener-resistor-capacitor shunt reg. outperform JSR or Sulzer. If so, then the more-sophisticated shunts (above) must be really spectacular – or are they?

Thx for any feedback you can provide.

[Onvinyl]

Originally posted by hollowman


Along with his own, Waagbo does credit Borbely’s shunt regs.

What do you folks think? Can a simple Zener-resistor-capacitor shunt reg. outperform JSR or Sulzer. If so, then the more-sophisticated shunts (above) must be really spectacular – or are they?

Thx for any feedback you can provide. [/B]

No wonder he credits borbely's designs -- the shown circuits are almost entirely a downgrade of those!

The claim 'better than jung' is, in this form, simply ridiculous. Specwise, jung beats anything so simple. The sound is a matter of taste, of course. My main concern with the proposed circuit would be to replace the zener with a really low noise assembly.

I *do* like shunt regs, even the fancier ones -- there are quite some examples here on diyaudio during the last few months, it's just simply both silly and unfair to bash the jung-didden circuit in comparison.

And yes, I think the shown ones will work pretty good!
Rüdiger

[hollowman]

Originally posted by Onvinyl
The sound is a matter of taste, of course. My main concern with the proposed circuit would be to replace the zener with a really low noise assembly.

Can you suggest a "really low noise assembly"? In any case, the author concurs about the noise in the article. But I think he ultimately feels the noise is a fair trade-off for whatever sonic gains/benefits the simple zener-based ckt provides.

I *do* like shunt regs, even the fancier ones -- there are quite some examples here on diyaudio during the last few months, it's just simply both silly and unfair to bash the jung-didden circuit in comparison.

Can you point to some of those "examples here on diyaudio during the last few months"? Links to the best of those would be helpful. Thx!

And yes, I think the shown ones will work pretty good!

If you build them, let us know. I'm having problems finding some of the parts.

BTW (and IIRC) ... about a year ago there were a series of articles in this same mag by Jung...praising shunts. I think the full versions of these 2007 articles may be found here:
http://waltjung.org/Late_Articles.html
Maybe the guy is re-evaluating his beliefs?

FWIW ...what I can says is that quite a lot of the really high-end CD/digital gear (Spectral, Wadia, Muse, etc.) opt for carefully-implemented shunt regulation, not series.

[peranders]

Originally posted by hollowman
What do you folks think? Can a simple Zener-resistor-capacitor shunt reg. outperform JSR or Sulzer.

Sure they can if the criteria is "it sounds better".

[Onvinyl]

Hollowman,
if you do a search with the criteria 'shunt' and 'search titles only' you may find e.g.:

http://www.diyaudio.com/forums/showt...424&highlight=

Bipolar discrete shunt regulators

http://www.diyaudio.com/forums/attac...amp=1139437025

http://www.diyaudio.com/forums/showt...81#post1399081

With really low noise I mean to avoid noisy zeners. You might try LED's , or use a low noise diode like LM329DZ, or might even get by with a CCS+resistor.

Don't get the impression I don't like shunt regs! I do love them. I wouldn't place my bets that a superreg couldn't sound darn good, that's all.
I'm trying quite some at the very moment, and will make a shootout between different regs with a mc-phono head amp (that is still on the to build list, anyway...)

Rüdiger

[joho]

Hi Gents,

The last time i'm playing with different regulators for my UGS-line amp(see UGS-thread on Pass Labs). I was very supprised last week when i reed the review in audioxpress about those shunt regs.
In fact i use the same simple shunt reg which was also a publication in AX a few years ago. Norman Taggard(i hope the name is correct) was the author.
I''m very satisfied about that circuit but replacing the shunt resistor(56R in my case) for the Borbely current source made no difference for me.
I.M.H.O. the power supply rejection of the used preamp makes the difference but the author of the shunt article gave not much information about the used setup and It's all written with a huge pro borbely cab.
As i said, i'm fooling around with different(shunt) regulator configurations but everytime that last cap is the bottleneck.
Yes, the panasonics FC-series are also very good for me. When i swap it for an elna audio grade i become depressive. But in fact we are talking about colouration.
How to solve that?

Gr.
Johan

[hollowman]

Originally posted by joho
I.M.H.O. the power supply rejection of the used preamp makes the difference but the author of the shunt article gave not much information about the used setup and It's all written with a huge pro borbely cab.

Nice work on your ckt! I found it somewhat similar to Peufeu's CCS/shunt PS. The AudioXpress author found the use of pre-reg 317 limiting (music more compressed), but maybe your design does not behave that way.

I, too, found that AudioXpress article confusing in certain regards (maybe it's the author, but the chief editor should've done a better job, too). Some main points of confusion regard component suggestions and labeling, notably transistors:

In the schematic below, what is:
- the FET transistor above the 221R (and what's its negative version)? (See below)
- the optimal negative version of BC549C and BC559C in the positions they are placed in the schematic? Are they indeed BC559C and BC459C, respectively?



The negative (-) version of a regulator -- sometimes, for better performance -- may not use the complimentary opposite transistor and/or topology. And, in any case, model numbers (nomenclature) for negative/positive pairs may not be so apparent; E.g. for output transistors … Positive N-channel Toshiba 2SK1530 compl. to Negative p-channel Toshiba 2SJ201. For shunts, author notes use either same as output OR Positive P-channel IRFP9140 and Negative N-channel IRFP150.

[joho]

Hi Hollowman,

The use of a pre-reg before the normal LM317/337 circuit isn't my own idee. Walt Jung and ALW did this before. I haven't the feeling that there is any compression. I can very easy make an A/B check and i didn't hear any difference but i found out that the last reg(the shunt reg) is very dominant. When i start to test the circuit i had some oscillation trouble but C2/C7 solved the problem.

The schematics in AudioXpress are correct but i used some screab.
IRF610/9610 and bc550/bc560.
So above the 221R a p channel fet (9610) and for the negative version mirror the circuit or look at the super shunt regulator circuit.
Bc459 huh ??? 549 i suppose.

In summary;positive supply, P-channel mosfet+pnp in CCS and P-channel mosfet in shunt. Negative supply N-channel mosfet+npn in CCS and N-channel mosfet in shunt.

Gr.
Johan

B.t.w. it can also different. Please take a look at the "shunty design" of ZENMOD on the pass forum.

[hollowman]

The schematics in AudioXpress are correct but i used some screab.

"screab"??

IRF610/9610 and bc550/bc560.

So, bc550/bc560 are your preferred substitutes for the orig authors choice of BC549/BC559, respectively?

So above the 221R a p channel fet (9610) and for the negative version mirror the circuit or look at the super shunt regulator circuit.
Bc459 huh ??? 549 i suppose..

Ooops: I meant BC549 (npn)! And, yes, BC559 (pnp) is the compliment.

In summary: Positive supply, P-channel mosfet+pnp in CCS and P-channel mosfet in shunt. Negative supply N-channel mosfet+npn in CCS and N-channel mosfet in shunt.

Right. But that leaves out the npn BC549C, in the SSR w/CCS schematic (see image posted earlier), whose base is between Vz and 100R. I assume this is changed to BC559C (PNP) for the neg supply.
c560 are your preferred substitutes for the orig authors choice of BC549/BC559, respectively?

[jacco vermeulen]

Originally posted by hollowman
"screab"??

screep-crab(b=p)
Norman Thagard (turns 65 this year iirc ,btw)