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ALWSR regulator

N

Naim2

pfm Member
Hi All,

Could someone please let me know where to get the ALWSR regulator?

I have been trying to look around for the boards but cant get any info so far.

Thanks,

David
 
Its an Andrew .L. Weekes Super Regulator and I think there is web site.
Also someone on here used to sell the pcb with or without the surface mount IC.
Someone will be along how knows what they are talking about.
 
The ALWSR pcbs are no longer available. About a year ago I got tracked down Patrick Dixon who was the guy who supplied the last remaining boards with Andrew's blessing I believe. He then said that if there was enough interest he could get some more boards produced. I didn't figure there was and/or didn't have the time to raise interest in another run of boards. Meanwhile over on Diyaudio there's a thread by Jan Didden, one of the developers of the Super-Reg upon which the ALWSR is based, in which he says he plans a new board. I think the boards may be going on sale through Linear Audio.

Meanwhile there are some quite competently designed and laid out super-regs available from Sjostrom Audio.

Personally I think the ALWSR design and layout is the best there has been but all super reg designs are "improvable" when the specifics of their supply source and loading are known.

What were you planning on using them for?

John
 
john.luckins said:
The ALWSR pcbs are no longer available. About a year ago I got tracked down Patrick Dixon who was the guy who supplied the last remaining boards with Andrew's blessing I believe. He then said that if there was enough interest he could get some more boards produced. I didn't figure there was and/or didn't have the time to raise interest in another run of boards. Meanwhile over on Diyaudio there's a thread by Jan Didden, one of the developers of the Super-Reg upon which the ALWSR is based, in which he says he plans a new board. I think the boards may be going on sale through Linear Audio.

Meanwhile there are some quite competently designed and laid out super-regs available from Sjostrom Audio.

Personally I think the ALWSR design and layout is the best there has been but all super reg designs are "improvable" when the specifics of their supply source and loading are known.

What were you planning on using them for?

John
Click to expand...

Hi John
Could you please post a link to the Jan Didden board thread over on DIYaudio? That sounds rather interesting.
 
The diyaudio store is in transit at the moment.I think everything will be available again once they are established in the new warehouse.
 
The circuit of the Didden board isn't quite the same as the ALWSR. The ALWSR has an extra emitter follower on the op amps output which puts less strain on the opamps output stage as it sinks/sources less current. This allows a higher setting of the current source from circa 6mA to 15mA which was reported by many at that time to bring forth sonic improvements. The details are in the ALWSR manual which is available online (google it).

As far as I can see it is possible and quite straight forward to bodge this emitter follower into the Jan Didden circuit board.
 
Hi All,

Thank you so much the information provided.

John, I am planning to use the ALWSR for a DIY power supply (Hicap) to power a preamp (Maybe a 62 or 32.5).

I wonder if the Teddy Super-Regulator is similar to the ALWSR sound wise?
Did anybody try a comparison?
 
It depends on the application i.e. what you are powering with it.

The ALWSR has a lower output impedance that the STRs, which will influence how well each regulator interacts with the circuit it is powering.
 
If it is a Naim 62 pre then the loading is one or more 27 ohm followed by a 47UF cap to earth in parallel with the amp stage. This is a pretty benign load for any PSU and it reduces the importance of having the very lowest output impedance which the ALWSR can provide but the high output impedance of the Superteddyreg may still have a bearing on the sound at low frequencies. This loading also ensures that an ALWSR will be stable when supplying it, which isn't always the case. The remaining factors in the choice of regulator are the noise and the line regulation. There's not much to choose between the ALWSR and the Superteddyreg on either of these although in the recent linear audio article there is a strange hump in the line regulation plot of the Superteddyreg at around 1kHz. Personally I would go for the ALWSR or Sjostrum/Didden reg taking great care with the ESR of the capacitors used in the circuit.

A simple cap multiplier in front of the Sjostrum/Didden/Jung reg has been reported to give a further improvement at little extra complexity. The ALWSR uses a tracking 3 pin regulator here.

John
 
Andy Weekes recommended removing the 47u/27R from the Naim preamp circuits and running a 0.5R in series with a 2.2uf SMR cap on the super-reg output (enough impedance to keep the reg stable). I did this in a 102 pre and it worked very well.
 
Jo Sharp said:
Andy Weekes recommended removing the 47u/27R from the Naim preamp circuits and running a 0.5R in series with a 2.2uf SMR cap on the super-reg output (enough impedance to keep the reg stable). I did this in a 102 pre and it worked very well.
Click to expand...


i know it's been five odd years but does anyone have more info on this mod?
 
I'm happy to be corrrected, but didn't the "golden age" of super regulator circuits precede the latest generation of surface mount more-than-3-pin integrated regulators?

e.g.

ADP150
TPS7A400
LT3042

Even if these new integrated regulators don't beat the classic super-regulators "out of the box" they would surely be en excellent basis for a new generation of super-regulator designs?

BugBear
 
bugbear said:
I'm happy to be corrrected, but didn't the "golden age" of super regulator circuits precede the latest generation of surface mount more-than-3-pin integrated regulators?

e.g.

ADP150
TPS7A400
LT3042

Even if these new integrated regulators don't beat the classic super-regulators "out of the box" they would surely be en excellent basis for a new generation of super-regulator designs?

BugBear
Click to expand...

Super Regulators are still substantially better than these IC's and much more versatile in the range of voltages and max currents they can be built for. They are very difficult to get right in PCB layout! The new IC's are very good though and an order of magnitude better than older designs.
 
Jonathan said:
i know it's been five odd years but does anyone have more info on this mod?
Click to expand...

I ran a 32.5 with six ALWSRs, one for each board. The boards had the 47uF/27R removed, replaced with 0.5R in series with a 2.2uf SMR. It sounded fantastic. I have also used ALWSRs with the Naim MC boards, each board supplied by two SRs again with 47uF/27Rs removed, replaced with 0.5R in series with a 2.2uf SMR. Sounded amazing until I built a Paradise MC amp.

ALWSRs seems to have fallen from grace on PFM, replaced with TeddyRegs. Though personally I preferred the ALWSRs.

I've moved on to the B4 pre-amp via a Starfish.
 
You don't need to add 2.2uF and 0.5R to the boards! Remove 27R and replace with wire link and remove 47Uf cap. It shouldn't really be necessary at all but for piece of mind put 0.5R and 2.2uF in series across the actual output of the regulator.

Adding resistance in line with a regulator defeats the object of it. In the case of Naim gear there is no point in even having a regulator whilst the 27R resistors are there... Hi-cap, flat cap, etc etc all pointless. Regs should be at point of load also so in the pre amp not in the PSU box.

ALWSR's are vastly better than Teddyreg with much lower output impedance.
 
The 2.2uF and 0.5R were there for stability ofothe reg if I remember Andy's words.

I had the SRs in the Naim 32.5 box, right by each board.

As I said I preferred the ALWSRs to the Tettyregs.
 
chiily said:
The 2.2uF and 0.5R were there for stability ofothe reg if I remember Andy's words.

I had the SRs in the Naim 32.5 box, right by each board.

As I said I preferred the ALWSRs to the Tettyregs.
Click to expand...

If you are not driving a capacitive load there should be no stability issue. The 2.2uF and 0.5R can be fitted to each reg as a bit of extra security but (just in case it's not clear...) should go from reg output to ground and should not replace the 27R and 47uF. Remove the 47uF and replace the 27R with a wire link. A Super Reg can have much lower output impedance than a lorry battery so it rather defeats the point by adding any series resistance! :)
 
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