[PT914]

Hi Hugh,

Thanks for the parts for my new power supply.  Just put in the right channel power supply based on the SS section of the GK-1 into my active crossover.  Big difference and very interesting comparing the old left power supply with the new right power supply.  All the sparkling and exciting parts of the music is coming from the right two thirds of the sound stage.  Same thing happens when I reverse the right and left channel at the CD player  Cannot believe the old power supply was that dull.  Maybe I had to much filter capacitance.  Each channel draws only 180 mA and I had 4700 uF per rail.  Anyway your power supply is so simple yet sooo good.  Oh I did destroy a zener and a transitor, that is why I only have one side for now.  I got the collector and base of the transistor mixed up  The left side power supply was just finished and is now burning in.  I did add a 20 uF Solen and a .22 uF Multicap RTX for down stream filtering.

Thanks again and great design!
Philip

[AKSA]

Hi Phil,

Thank you for your feedback;  I'm delighted it works so well!

Darl Singh and I noticed the profound effects of power supplies when we developed the GK1.  We tested IC regs, and found their measurements blisteringly good but the sound flat and lifeless.  I guessed that the two most important features of power supplies were speed and source impedance, and this led us to the simple emitter follower.  All the hoohah about microvolt regulation revealed itself as a blind alley;  only the emitter follower has a falling source impedance with higher current, AND it's the fastest configuration known.  Any feedback from output to input in a conventional linear regulator will correct after the event, albeit very quickly, and even if it's very fast it will simply insert tiny ringing artefacts into the supply as the error correction takes effect.

A great deal of the semiconductor physics you see in power supply design is based on instrumentation, which does not apply in the psychoacoustic world of careful listening because voltage regulation per se is not so important as speed and low output impedance at high frequency and high current.

Cheers,

Hugh

[econ]

where is  Darl Singh these days ?

[AKSA]

HI Paul,

How's sleepy hollow?  (I refer to your august Operating Theatre....... )

Darl is in Hamilton, Enzed, running a stainless steel fabrication business.  Lovely guy, hope he's reading this.  One day I will visit him!!

Cheers,

Hugh

[PSP]

Hi Hugh,
So..... do you think there might be an Aspen power supply kit in the reasonably near future?  I'll be building the Orion XO pretty soon, and it needs a power supply... +15 0 -15v, and ~200-300ma for both channels.  I suppose dual mono would be better, yes?

Thoughts?
Peter

[AKSA]

Peter,

There is mileage in this.....  yes, I think so.

I'll keep you apprised of developments!

Cheers,

Hugh