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Neil McCauley
31-12-2008, 19:05
I predict that 2009 will herald a significant increase in the understanding of, and appreciation of the crucial importance of mains purity in relation to sonic credibility.

By this I mean that the false dawn of mains conditioning and filtering will be shown up for what it is when compared to mains regeneration. In short, my hope is that confusion, and those that so confusion - will at last be confounded.

Having now installed literally dozens of PS Audio Power Plant Premier mains regeneration devices and taken careful note of the readings, I am now utterly convinced that the mains cleaning approach adopted by mains conditioning and filtering is fundamentally flawed and was a dark and dynamics-sapping cul de sac which might fortunately be coming to an end. And why do I say this?

The PPP measure incoming THD on the mains. Typically this is around 3.1%. By and large it reduces this by around 90% i.e. typically .3%. Sometimes even lower.

I’ve fiddled around with changing input and output voltages. Interesting, but in no way as dramatic as reducing the THD. Mains conditioning and filtering does nothing to reduce THD in my experience.

In contrast, all of those other silly and expensive mains conditioning and filtering devices I have experienced have proved in general to be worthless in comparison to proper mains regeneration to the extent that not only do I not take them in trade in but I no longer offer to sell them on commission – simply because I am utterly unable to demonstrate any improvement whatsoever. And I don’t mean compared to the PS Audio device, but in isolation. Changes? Yes! Improvements? None!

Yes of course I can bend the demo to enable me to sell this unwanted tosh. It’s easy. Just put on a poorly recorded CD, something pretty harsh in the vocal should do and the mains conditioning and filtering can make the previously dreadful sound more tolerable. But put on (say) a piece of cleanly recorded full orchestral music, and the sound becomes undynamic – as if by magic.

Is this a paean to PS Audio? At first sight you might think so. But it’s not intended as such. No, rather an admiration for the careful application of technically assured engineering principles to the importance of mains. Currently – PS Audio have the market to themselves. My prediction for 2009 is that we are going to see home grown mains regeneration devices and the none-too-soon death of the expensive toys that claim to do as much through filtering and singularly fail to do so outside of the pages of the magazines who rave long and hard about them.

Mike
31-12-2008, 19:16
The PPP measure incoming THD on the mains. Typically this is around 3.1%. By and large it reduces this by around 90% i.e. typically .3%. Sometimes even lower.

Interesting Howard, do you rely on the figures from the PPP, or do you have any independent test equipment to corroborate these figures?

I'm not trying to cause any controversy, nor question your findings. I'm genuinely, and increasingly interested in this sort of thing.

Thanks.

Neil McCauley
31-12-2008, 19:34
Interesting Howard, do you rely on the figures from the PPP, or do you have any independent test equipment to corroborate these figures?

I'm not trying to cause any controversy, nor question your findings. I'm genuinely, and increasingly interested in this sort of thing.

Thanks.
You raise a most interesting point, and one that I should have addressed. Thank you for bringing it up.

When the PPPs come into the country, they do need calibrating. A bit time consuming and a bit frustrating and as far as I can see, avoidable. But it is what it is - so I do it.

Although not explained in the handbook, for PS Audio retailers there is a tuning screw. Basically this enables the output voltage to be adjusted until it is at 230v. However, the skill is to balance that output voltage (or vary it if you prefer) to correspond to the minimum possible THD. Thus the lowest THD might occur at a voltage that's not precisely 230v. So in essence, a little bit of juggling goes on to get the optimum balance between the lowest THD and the closest approach to 230v.

PS Audio retailers are provided with a simple device to measure the actual mains voltage from the wall socket and the mains voltage from any of the 5 outputs of the PPP.

As for THD input and reduction, I rely entirely on the PS Audio's own readings.

Hope this helps.

Best

Howard

Mike
31-12-2008, 19:39
Thanks Howard,

It helps, erm, and it does not! I'd love to know the quality, or otherwise, of my own incoming mains supply. I'll have to investigate methods of measuring it.

Cheers...

Spectral Morn
31-12-2008, 22:48
Hi Howard

While I have no experience of the PS audio unit, I have tried an ISO -8 Mains regenerator and it seemed to offer a big improvement over filters etc. However taking it round different customers homes ( and thus varying voltage fluctuations ), it did not always produce the same results. In my own set up, I was frankly blown away by it, but in other systems the degree of improvement was reduced or even canceled. This unit had a + or -10 on the degree of regeneration so it was happy at 230 to 240 but could also cope with 220 and 250 volts. The display for what it may have been worth never showed much below 230 or much above 243 volts, where tried. However on customers mains and I saw it was about 225 on one day when I took the unit round. I felt it offered an improvement, though small the customer didn't.

How have you found the PS audio to work within those sort of ranges ? Have you encountered such drops in London etc ? Did sound improvement vary at all, depending on incoming voltages ( when the drops or rises were high) ?

regards D S D L---- Neil :)

Neil McCauley
31-12-2008, 23:43
Hi Howard

While I have no experience of the PS audio unit, I have tried an ISO -8 Mains regenerator and it seemed to offer a big improvement over filters etc. However taking it round different customers homes ( and thus varying voltage fluctuations ), it did not always produce the same results. In my own set up, I was frankly blown away by it, but in other systems the degree of improvement was reduced or even canceled. This unit had a + or -10 on the degree of regeneration so it was happy at 230 to 240 but could also cope with 220 and 250 volts. The display for what it may have been worth never showed much below 230 or much above 243 volts, where tried. However on customers mains and I saw it was about 225 on one day when I took the unit round. I felt it offered an improvement, though small the customer didn't.

How have you found the PS audio to work within those sort of ranges ? Have you encountered such drops in London etc ? Did sound improvement vary at all, depending on incoming voltages ( when the drops or rises were high) ?

regards D S D L---- Neil :)

The lowest was 217v input. Clearly a problem with the utility supplier. The PPP brought it up to 231v without a problem. Highest so far is 257v and the PPP brought this down to 241v.

In experiments here, I have been unable to detect any sonic difference with any item when my own PPP has be set to give 230v or 240v.

The only 2 home demonstrations which have not automatically resulted in a sale was where Audio Research tube preamps were in use. Also one where a rather fine Accuphase Integrated was used. This might be nothing more than coincidence. The sample rate is too small to be significant.

Typical THD across my installations is 3.1% input. The lowest anywhere so far is 2.5%.

I am unable to determine any correlation between the size of the THD and the variance from a 230v datum.

I borrowed Nic Poulson's Isol-8 for a show in Manchester a couple of years back. The results were inconclusive.

Spectral Morn
31-12-2008, 23:48
HI Howard

I guess I will just have to try one at some stage a P S Audio regenerator

Regards D S D L ---- Neil :)

MartinT
01-01-2009, 07:50
My own PPP shows an input voltage of 252V (I live in a new development with its own substation) and the output is rock solid at 241V. THD improvement very much in keeping with Howard's findings. As for sound improvement, I have waxed lyrical elsewhere but suffice to say that I would now never run a system without one.

Dave Cawley
01-01-2009, 15:06
When you say 3.1% THD, what are the distortion competents ? Is it second, third harmonic, or general noise?

Dave

sastusbulbas
01-01-2009, 16:05
PS Audio retailers are provided with a simple device to measure the actual mains voltage from the wall socket and the mains voltage from any of the 5 outputs of the PPP.

Howard

Why measure the mains voltage from the wall? It may not be constant and can fluctuate during the day can it not? My own power amp sometimes seems to show this with a little hum coming and going from the case at certain times, I think it is the transformer making noise with the fluctuating, and the Mana table amplifies this case noise?

Does mains fluctuation not get regulated by the PPP anyway?

I like the look of PPP myself but cannot afford it, I also think the purchasers who live in the states get a better product, as it was initially designed for their voltage, they get 10 sockets, and the "up to 50 amp" output seems a little confusing when UK sockets have 13amp fuses :confused:

I myself am using unfiltered RA blocks with eight sockets each, with my Krell power in its own socket as it can draw up to 2k from the mains (which I have been left to believe is best in it's own socket).
Most of the filters I have tried I feel have offered no benefit, or been so subtle it may have been imagined or have squashed dynamics and softened bass.

Steve (Happy new year!)