Romy the Cat wrote:

The second action is a process of active injection of sonic particulars into down-line components….. That dual activity should be always understood as two separate elements of PurePower’s contribution.

What the Super Texture is and where it comes from? I have no definitive idea. The PurePower regenerator is in a way a “radioactive” switching machinery that throw around HF impulses, spreading them via different methods (radio, magnetic, electrostatic, grounds, etc….).  I presume that some of the residual “radioactivity” might leak into playback, affecting it as a very “special dither”. The residual ripples of the PurePower’s sampling raters (20Khz) are relatively high, and well visible on a scope. I presume that because a huge parasitic capacitance of APS unit (the whopping 28V between ground and neutral) that residue of the switching wrinkles leaks to ground and then goes to the cathodes… I have to mention that I made many experiments trying to detect that “wrinkles penetration” and was not able to, at least for now. Perhaps the residual wrinkles are not the reasons of the APS Super Texture, perhaps something else is.

Whatever the reasons of Super Texture are it should be understood that the Super Texture is homogeneous hybrid with PurePower’s First Action (power regeneration) and they are VERY mush alloyed together. Use of APS generator is an ability to manage the intensity of the Super Texture. It is not so straight forward and I will tell about it my brief forthcoming Survival Guide

Do not be under impression that this Super Texture is strictly positive moment in APS. The Super Texture might be us a horrible enemy, in fact in most cases it is, something that converts the Sound f playback into Absolute Sound advocated “frequency pushing”.   The Super Texture is like “Unsharp Mask” in Photoshop – with moderate and restful application it might be very useful and beneficial too but as soon it gets slightly more than necessary it converts a photograph into visual garbage (an example is most of the phonographs at my site)

It is important to note that the “Super Texture Garbage” or the effect of “Overly Applied Dither” that you might get from PurePower regenerator in most of the cases will be VERY welcomed by audio pubic. I heard drooling comments from audio morons about PurePower but I never have seen/heard anyone’s caution tales about the devastating effect the over-application of PurePower’s Super Texture might have to sound. I hope my Survival Guide will be taken under consideration by people who use APS unit or perhaps some others who have different view but better sound would voice their recommendations to me.

Finally, the PurePower regenerator does not address problems of playback with electricity – you will see later on why. However, the APS unit opens a whole new perspective of looking at the things – pre-structuring power in a certain format in order to get certain effects. Have you seen Power Level Injection Channels? Here we go – the APS devise does exactly that. The APS PurePower regenerator did not become my “all problems are off” solution but it becomes a quite valuable tool to shape better sound. I would like to be able to moderate the amplitude of the First Action and Second Action but APS does not offer it. APS, as most of other manufactures care only about functional moments of their units in context of terminally deaf and sonically Moronic audio pubic - it is hardly possible to demand from them any sonic specifics. In the end, after my Survival Guide, I will pass some my recommendations where I would like to see the APS and APS-like devises to go from where they are now.

Romy the Cat wrote:

Finally, the PurePower regenerator does not address problems of playback with electricity ..

Dear Romy, regarding your efforts to solve variations in mains power supply, there has been an interesting thread on RAT related to the use of toroids as power transformers that morphed into a discussion about the level of DC offset in mains power supply and possible solutions.  I thought you might be interested in the gist of the discussion because it contained much useful information, as follows.  Regards, Peter Foster.

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Mains are polluted everywhere. Typical DC offsets are 0.8 to more than 3V (!) in Europe. I guess that North America is as bad - or worse.

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So, aside from hair dryers on 'half power' what causes it?

** Asymmetrical loads on the supply - dummy. Don't much care what they are. Just depends what is going on around where you live.

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DC offset is a big problem nowadays, with more and more switching power supplies w/o proper power correction in every home (it's even worse in offices). As toroids work very close to core saturation, even a small amount of DC offset wreaks havoc.

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Mains DC offset exists in all countries - only a matter of luck of your local AC supply has no DC offset. The effect is dramatic on a toroidal power transformer.

Example: 300 VA, 240 volt 50Hz AC toroid (unloaded).

#1 Offset free supply:
I mag = 15mA rms / 25mA peaks.

#2 Supply with 1.2 volts DC offset:
I mag = 715 mA rms / 3.9 A peaks.

In case 2, the transformer is heavily saturating on one half of each AC cycle PLUS is drawing 171 VA - while OFF LOAD !!!!!!!! BTW 1.2 volt DC offset created by using a Black and Decker 1600watt ( handyman) hot air gun, set to half power.

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Phil's heat gun set to half power could be a problem, as it likely uses a rectifier diode to conduct on say positive peaks of the powerline only.

** Correct.

And if your house wiring has enough Thevenin equivalent impedance (American powerline 15A outlets are around 1/4 ohm)

** That figure is around 0.5 to 1 ohm in Australian ( 240V ) homes.

Running the hi-fi on its own dedicated branch circuit from its own circuit breaker in the breaker panel greatly reduces that offset from that heat gun. There the powerline impedance is more like 1/40 ohm, for a 150 amp service. Or maybe 1/20 ohm if your power company cheaped out on wire size...

** Some folk have around 0.5 volts DC offset most of the time.

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Dunno if there is any way to complain about it to the energy suppliers.

** There isn't because it isn't part of the tariff to have no DC offset. At least in the US, the tariff-the statutory rate you pay the utility they agree to in exchange for the monopoly on power-says what you are and are not entitled to.

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Mains dc offset isn't a stable thing, and the dc offset is really just slow moving LF content. You'd see what LF shite there is in your mains supply by having a very steep cut LPF with a pole at say 20Hz to remove easily visible 50Hz and harmonics. An LCLCLCLC type filter will do it.

The mains is a noise source due to thousands of users all around you switching things off and on, and with so much continual switching, the result is a mains voltage that rises and falls with its varying shared load. There is a resultant content in all this noise which can be filtered out, and if you had a filter resonant at 0.1Hz, you would see a varying signal at this LF. It is so slow a signal wave that it acts like varying DC, but dc that varies is NOT dc anymore, eh.

The average load at your house is determined by the generator and wiring from generators to you, and all the transformed down high Z of the network. But at any given time, there are so many folks drawing power that there is the equivalent of a giant low value resistor shunting the mains supply. If the average input current is 4A to your house, the load of your house = 240V / 4 = 60 ohms. 4A might seem a lot, but 2 ppl in a house average around 1000 watts 24/7/365.

1,000 houses sharing the same mains wiring gives a load of 0.06 ohms, I = 4,000 amps. Noise generated across town won't appear near you because the wire resistance across town is considerable, and switching transients get smoothed out by inductive nature of the wires. With the shared R load being so low, the amount of L needed to attenuate HF isn't much. However, because the mains are effectively a huge informal antenna array, there is a largish RF content present.

If a negative swing lasting an hour before its swings the other way, don't ask the utility company for a refund. Every silly question has already been heard across the counters of power companies... Just wait until we all switch to electric cars and nuclear power stations. We will be seeing much more work for electrons to do.

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This company in the Nederlands has a box incorporating the ( well known ) solution to the DC offset problem.

http://www.kempelektroniks.com/PowerDCXTerminator.aspx

Make sure to click on the CRO screen to see a neat simulated demo.

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The above link raises the question, how is DC offset reduction achieved in the 1.2 kg item offered?

** By simply AC coupling the PT primary to the AC supply. The weight must be all in the (lead) alloy box.

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Do they just have a pair of large value series capacitors in series with mains active and neutral?

** I would say back to back caps shunted by a string of diodes. That's the usual way to block DC.

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But does not an ordinary isolation transformer remove the dc at the sec?

** Of course it does. But if you run a toroid isolation transformer close to saturation, you've just moved the problem.

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The above link raises the question, how is DC offset reduction achieved in the 1.2Kg item offered? Do they just have a pair of large value series capacitors in series with mains active and neutral?

If there is a varying level of dc, it really means you have an added LF wave between active and neutral. The neutral is at ground potential as it is tied to earth at the house earth connection. Hence the jittery level of the mains wave shown on the CRO.

But does not an ordinary isolation transformer remove the dc at the sec? And in any case, the very low F "dc offset" is small and should not have a serious effect on the maximum Bmax of the PT.

But mains voltage does change in amplitude from minute to minute, and raw Vdc after rectifier diodes changes continually, so depending on mains 50Hz voltage variations, and music caused dc load variations on the PSU from largely class B amps, the transformer and rectifiers are seeing a varying load at all times.

Transformers should be designed to take a 10% extra input voltage indefinately. I forget the exact words of the Australian Codes, but imported stuff is supposed to comply.

Many trannies would hum quite badly and perhaps thermal out if they were forced to accept 264Vrms instead of the usual 240Vrms we are supposed to have.

Chinese made trannies designed for 220Vrms don't fare well, as do US mades with 230V connection but rated for 60Hz.
And here we have 250Vrms measured most days. It isn't a nice sine wave like the one shown in the CRO pic at the above URL. What we have here is a triangular wave with flat crests which have a total length of about 1/4 of the whole wave cycle lengh. It means the equivalent of maybe 10% odd order harmonic distortion.

And BTW, I loath toroidal trannies because most are so poorly made. Good ones are well varnished internally, potted, and don't hum because sufficiently high TPV are used to keep Bmax less than 1 Tesla, and thus be able to pass tests for over-voltage without saturation effects making them noisy or hot.

These good toroids are of course larger and heavier than what we see in the crummy budget audio gear which is 95% of what is foisted onto the public. Makers don't like paying the costs when once you get above a certain quality criteria, welded E&I cored PTs are the better thing for cost and performance.

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The majority of commercially designed transformers are designed to run with Bmax at whatever figure gives the wanted rise in T, and with about 3A per square mm for current rating in the wire. Toroidals are run at maybe 1.3Tesla, and right on the onset of saturation.

Current spikes can be seen in the wave form with no load. So if B is increased 10% with a 10% mains voltage rise, the spikes are larger. However, the core material can be such that it still won't get hot.

With load, the current wave is dominated by the load current, and the spikes due to saturation effects are not so obvious.

Presence of DC, say 1V would to me seem like a heck of a lot of DC and very unusual for mains supplies, but if present, the dc current through a low resistance P winding could cause Fe magnetization and more serious saturation current spikes. But any other E&I transformer could also suffer similarly, depending how close to saturation is it running. But because so many mains users have transformers connected to the mains at any given time, and because the resistance between active and neutral is so low, the presence of Vdc generated by stray devices connected tends to be very low.

The simple way to make sure any tranny stays cool, does not hum mechanically, and can sustain some DC and not hum badly with a rectifier on the sec feeding large C with Si diodes is to design the tranny with B < 0.9Tesla, which means most makers would have to increase copper turns about 30%. Bean counters alweays say farkin no to this, and to get them out of their silly mindset, should have a decent sized E&I shoved where the sun don't shine. If the turns are increased, there has to be more room for them, and the wire must be thicker to maintain copper resistance and the copper losses. OR the Afe core size must be increased 30% which reduces B 30% for the same turns per volt.

There majority of toroids available are wound as a cheap lightweight alternatives to old fashioned E&I trannies, but I am very reluctant to use any of them because they all have Bmax far too high, and although they rarely get hot, they can be noisy when rectifier output is needed.

If they are designed with B < 0.9 Tesla, the weight/size and cheapness advantages dissappear because such a toroid is a special order.

The right way for a toroid to be wound is with finely woven cloth insulation material placed over the core to prevent sharp edges biting the wires, and then all layers have no overlapping turns, and have a layer of insulation tape wound on between consequent layers of wires. Once completed, the transformer is soaked overnight in varnish, and drained of excess then baked to cure the varnish to make good solid bond between core and layers of wire. The woven material allows the wet varnish to soak into the tranny; plain polyester film does not.

Proper construction as described is never ever done with budget toroids bought by furquit hobbyists trying always to avoid costs.

I'd always use toroids if I could find a source of cheap decently constructed types, but none are to be found whose cost is less than good E&I.

The design spec of say 0.85 Tesla will allow a mains tranny made for 220V 60Hz to be used with 255V and 50Hz, where the B would then be 1.11 Tesla. If designed initially for 1.3T, an adverse condition could give 1.8T, and serious saturation problems.

Audio gear should never have Bmax in power trannies higher than 0.85 Tesla. Bean counters never agree though. Hence all the shit we see that I will NEVER buy.

Chinese electrical items often seem to be rated for 220V only, and suffer badly with the 255V we see hear sometimes.. Chinese soldering irons get way too hot here and last only a month if you are lucky and need a box with resistors inside to drop the voltage at the iron. Then they last more than 18 months.

Some chinese amps don't like the 255V applied to the power trannies, because the B+ rises too high, but most have cheap E&I cored trannies which appear to take the missmatch of mains V OK.

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Toroids don't have an air gap, even the most carefully stacked E-I laminations have a residual air gap, are you telling me that doesn't change their characteristics?

Indeed the toroid spiral strip core does have a different characteristic to fine and well stacked E&I lams. Not only is there a microscopic air gap in E&I lams, or C-cores, but there is a change in grain direction of the Is and Es where they butt together.

C-cores don't have such a grain direction change. But they do have a cut and join. The effect of the butt join with E&I and cut and polished join in C-cores reduces the maximum µ available. With the GOSS toroid core, perhaps max µ = 40,000, and if the same material is used in E&I lams perhaps max µ = 17,000, and with C-cores could give perhaps above the 17,000.

NOSS material is non oriented grain steel with Si content but is never usually used for toroids, although it could be, not used for C-cores, but is used in cheap E&I cores and has a max µ when stacked close of around 3,500. NOSS if used for a toroid might lift the max µ to 5,000. All these steels are "special", and some more special than others, but they behave differently depending on the app. The frequency of saturation is only very slightly higher with GOSS than NOSS, but GOSS saturates more sharply than the NOSS. GOSS cores have much lower magnetizing currents than NOSS, and hence the GOSS runs cooler.

GOSS with high µ is now routinely used in E&I mains transformers where the cores are not interleaved at all but all Es are just butted to all Is, and the two bundles are machine welded. This saves an enormous amount of Joe's time spent stacking in the Es and Is to interleave them fully. People don't like doing the job Joe does; its very boring to spend all day stacking laminations. Some cores get machine stacked. but welded is cheaper. The resulting µ of the welded cores is well below what could be achieved with maximal stacking, but its adequate to get losses to be low enough.

Even ARC use mains trannies with welded cores.

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As promised yesterday, here are some more measurements as per your suggestions...and some others as well:

The Plitron toroid that I am using for the testing is an 80va unit wound for 20-0-20 volts at 2.0 A rms, and having a single 115 V rms rated primary.

I characterized it first with no DC offset, just to see how close to the limit it is designed in terms of saturation. The meter used for exciting current measurement is a Fluke 87 type III ("true" RMS...it measures only the true RMS of the AC component of the waveform. To obtain the true RMS, you need to obtain the DC component separately, square it, add it to the square of the AC component that the Fluke 87 measures, and then take the square root of the sum.) The exciting current waveform is observed using an HP465A AC only current probe. The peak value of the exciting current is designated Ip.

Voltage adjusted with 1.5 kVA variac:

Vin (60Hz) Imag Ip
volts rms mA rms mA peak

105 8.1 10
110 9.2 12
115 10.6 18
120 13.2 24
125 17.8 50
130 31.5 100

The exciting current waveforms start off at 105 volts in as what look like slow rise time square waves. This is due to the large amount of 3rd harmonic in the Imag. You don't normally see this behaviour in EI transformers as the flux density cannot be run this far into the knee of the BH loop without experiencing unreasonably high core loss. But with all the flux in the toroid being in the "easy" direction of core magnetization, you can really honk the flux right up there without excessive core loss, and that's exactly what Plitorn did with this design.

By the time you reach 115 V the Imag waveform shows some "tailing up" just prior to its falling edge, indicating a closer approach to saturation. Note the relationship between Ip and Imag. At 105 Vin, Ip is only 1.23 Imag. By the time 115 V is reached, Ip is now 1.70 Imag. At 130V in, Ip is 3.17 Imag.

Although opinions (and measurement standards) in the industry may vary as to the exact onset of saturation, there is no doubt by any definition, that I have ever seen published, that we are soon to be in trouble if our input voltage exceeds 130 V. This toroid by the way was sold for use in North America where nominal AC line is typically 120V. It is not unusual to encounter 130V in some areas during light load periods.

Now for the offsets:

Offsets are measured using a low pass filter consisting of a 100H inductor and 20uF polypropylene cap. The voltages are measured with a Beckman DVM.

There is no variac used during these tests as its series impedance in addition to that of the AC line tends to greatly increase the DC offset. We do not want to exaggerate the problem.

1) Measure offset using 40 W, 120 V incandescent bulb with series 1N5406, measure Imag.

Connect the 40 W bulb and diode on same branch circuit. Voffset = 47mV dc
Ioffset = 47mV/3.6 ohms = 13.06mA dc
Imagac (13mAdc offset) = 28.5 mA rms , Ip (offset)=100mA peak

Total Imag = sqrt(Imagac^2 + Ioffset^2)= 31.4mA rms

And remember that from our previous measurements on the toroid:

For 120 V rms in, Imag (no offset) = 13.2 mA rms, Ip (no offset) = 24mA peakSo for the single 40 W bulb, the peak current increases by a factor of 4 and the RMS current by a factor of 2.4.

2) Now let's make this look like a cap input filter load, still with a half wave rectifier and try to keep the load POWER the same as in the simple half wave rectifier and 40W bulb example.

This will require our 1N5406, a filter cap of 1500uF (to keep ripple across the load insignificant) and a load resistor of ~1445 ohms. After building this up, here are the results:

Voffset = 30mVdc, Ioffset = 30mV/3.6ohms = 8.33mA
Imagac (8.33mA offset) = 20mA rms, Ip (offset) = 100mA peak
Total Imag = sqrt(Imagac^2+Ioffset^2) = 21.7 mA rms

At first this does not look like as bad a case as the 40 W bulb and diode, which also looks like a 20W load but with a much longer diode conduction angle. The peak current however in the toroid primary is just as bad, so the threat of saturation is just as serious...particularly if the AC line voltage were to increase to 125 or 130 V under this condition.

If I had a better current probe, like one of the modern Tektronix units, I could better examine all of the peak currents and give some better answers. Using a shunt resistor to measure currents here is not an option as an isolation transformer in the AC line has sufficient impedance to really exaggerate the DC offset, and floating the 'scope is not an option for the sake of safety.

3) Now what about if the DC offset source is on another branch circuit on the same leg of the 120-0-120 V supply?

Using the original 40W bulb setup on another branch circuit, the effects on the toroid were reduced substantially.

Voffset at transformer = 12mV dc, Ioffset = 3.33mA
Imagac(3.33mA offset) = 14.3mA, Ip (offset) = 42mA
Total Imag = 14.7mA

Examine the results in the first table and compare.

4) Hair Driers etc.

I have two hair driers here. One is a less than 2 years old and causes no DC offset on either of its two speeds. The other is a Braun drier that it still in excellent shape that I have had from my university days in the early 70s. It still works well but produces 500mV of offset on the AC line when used on its low speed. Judging by how long mine has lasted, I'll bet there are still quite a few of these out there, owned no doubt by parsimonious old farts like myself.

I also have however, quite a recent model of heat gun, a Balck and Decker Heat and Strip Model 9756. This thing, on its low speed produces 1.2 V dc of offset, causing the Imag of our toroid to exceed 1 amp rms! Even when used on another branch circuit, the Imag in our toroid hits 140mA rms with peaks of 600mA. So asymmetrical loads on the AC line can be a real problem if a toroidal transformers is used on the same branch circuit. Stating that such loads don't exist, or should never exist, is just wishful thinking.

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Yes, Peter, thanks, good reading.

I research the DC offset and toroids subject as well. I think it is not as bad as it is portrayed. First of all it is not complicated to make toroids with gap, sure slightly more expensive. Also if do not save money and wind toroids with a large space current then DC offset will not necessary through the cores in saturation with moderate DC offset. In the super Milq I decided to stay with IE transformer for plated and toroids for filaments. The Milq filament transformer is kind of much larger then it needs to be but also Milq uses indirect heated tubes. I wonder if the IDHT heater do have a transformer with a few millisecond pre-saturated core… then so what?

BTW,  the company the you point out in your test has an interesting products:

http://www.kempelektroniks.com/PowerStation75.aspx

peter foster wrote:

The UPS units are being used in their normal way, as line interactive.  The voltage waveform supplied by the Powerware 5115 is a sine wave.  This is described briefly in the manual and was important information for me pre-purchase.  At the time of my investigations, I consulted a number of people with expertise in the field of mains power supply regulation and amplifier and transformer design and came to the conclusion that the minimum requirement was for a perfect sine wave output, no fan and for a unit that was proven with large scale commercial server systems.  After receiving one unit and testing it the results were acceptable and the cost reasonable so I then purchased more.  There is also a manufacturers warranty supplied for equipment connected to the UPS units.

Peter, I am sorry to inform you but it is not exactly what it is, and I am surprised how people in the fields did not explained it to you. The line-interactive unit buy definition have no own waveform what power is present.  You might Google the definition of line-interactive UPS unit of you might look at my file: (figure #2)

http://www.goodsoundclub.com/PDF/UPS.pdf

As you might see the line-interactive what the power is there work in complete bypass mode and the own DC to AC inverter is not activated. If you put a scope before and after the line-interactive UPS unit then you will see absolutely identical waveform before and after. The UPS unit will filter some HF noise but it is about it. Without the input power the line-interactive begin to regenerate a new own waveform. The quality of that waveform and that electivity for audio is a separate subject. I did test 3 commercial line-interactive UPS units, including two large and expansive – none of them I found were useful, at least as is.

peter foster wrote:

But that is only part of the story.  The other parts include use of a dedicated branch line for each unit and perhaps even more importantly the design of the amplifier power supply itself which can do much to supply consistent performance with inconsistent mains power supply.  The schematic for the amplifier power supply is described at http://www.turneraudio.com.au/8585-amp-october-2006.html if you are interested.

Yes, I did detect with my own experience that the more chokes in supplies, partially the input chokes the less sensitive amp for electricity problems. Voltage anomalies are just a part of the story. In class A amp the current consumption is constant but current flow atop of voltage waveform, that most of the time is truncated. So, we can stabilize currant without caring about voltage. How? The input chokes that store current and that demonstrate current inertia even if voltage sinks, also chokes are effective low-pass filter against the line noise (thought they do not work at UHF, you would need different chokes for that). As far as I concern, more chokes and higher current make amps less care about power problem. I have written that Super Milq is way less sensitive to power problems then my front end.

Well, my ride over the APS PurePower wave did not finish yet. As this point I am convinced that my PurePower unit #5 is also defective. I have a conversation with PurePower people and they will look into it. I still fill that my unit #1 and my current the unit #5 are basically the regenerators that operates and sound differently. Let see what the APS investigation would show.

Also, I passed to the APS people an idea how to eliminate the biggest from my point of view shortcoming of this regenerator. If they go for it, and AI hope they should then it might be a very interesting APS revision and it would give to the APS a momentum to introduce a “new” product. I doubt they might go for it driven by sonic consideration but they might like it as marketing tools to make the Morons who use currently PurePower regenerators to buy “new” PurePower units. If the release of the new PurePower, let call it “PurePower Premier” :-) would be bitter with good white paper and good literature then it might be something that make APS people to consider it as a next move. I do invest into this opportunity keeping my useable and from my point of view faulty operating PurePower regenerator in my storage.

Antonio J. wrote:

I really can't understand how a company selling a power regeneration device priced well over 2000 or maybe 3000 USD could send you 5 units and being al them "defective". Did I miss anything here?

Nope, you do not miss anything. However, there is some “twist” in the unbelievable fact of the fifth not properly functioning/sounding unit. Let me to explain. I had 5 APS units:

1)     Fully operational. I retuned is in 2-3 days as it did not works/sound well against input-choke PS and at that time neither I nor APS knew that their design can’t to be used against input-choke PS
2)     Turned out to be defective – droved front end but burned out as soon power up was connected. The Super Milq draws 7.2A during its initial start up and has 8A slow-blow fuse in the unit and 20A fast-blow in dedicated line. According to specification the APS unit should be able to handle up to 30A in bypass mode. It is true that the unit #1 was handling the Super Milq’s start up for 20-30 times with no complains.
3)     Prototype unit. Was returned as it sounded like shit, even worse. I usually do not comment publicly on prototypes or experimental units that manufactures send to me but in this case it is different because ASP clams that there is no difference between the prototype and production run. The production units however sounded absolutely different then the prototype. Very strange.
4)     Fully operational and OK sounding unit. Got burned up in 2 days because unknown reasons.
5)     Fully operational unit that I use now. I still am sorry the I got the file unit go as it was, I feel the best sounding among all.

So, from one perspective I did not have a good luck with APS devise but as soon I had problems APS people replaced the defective unit. Does better service compensate a questionably-reliable product? Well, here is where important to understand that I do not give a shit nether about the reputation of PurePower regenerator nor about prestige of APS as accompany. I just do NOT try to make my opinion about a “product” but rather to care about my specific problem with Sound and the ability of this or other tool to address those problems. Yes, I do not like that the APS people too damn lazy or ignorant to deigns in their device a proper protection, properly QA this products and make sure that the released unit meet basic specification requirements. However, among all power devises that I have the only one APS regenerator did deliver (for 2 days!!!) the demanded tonal and harmonic transparency. I am not exactly look forward to buy the ASP stock but rather to use this regenerator to power my front end. I do see a lot of potential in the direction that ASP went and it is possible that if APS people will follow Sonic Objectives then they might end up with a good product. The bugs in their unit? Well, I hope they will trace them… preferably before my warranty expires. My primary concern is now is that my current unit does not perform, sound and might  not be used as the unit #1 was. The APS folks are looking into it. Would I like to have a properly sounding problem-free solution? Sure I would, do you know any?

Antonio J. wrote:

The idea of the Kemp for the Bidat, CEC and maybe phonocorrectors seems interesting. I could try it myself, but my judgements probably wouldn't be any worth for you.

http://www.goodsoundclub.com/Forums/ShowPost.aspx?PostID=2589

Romy the Cat wrote:

I looks at the statistics page of my site and it looks like there were zillions Netherlandiams visiting the site. I wonder why they don’t say how the Kemp regenerator sounds. The judgment part? Well, this is an easy part. You have your power devise and plug it in the power lines during the times when electricity sounds very good. You should not have any sonic, perceptible, imaginary, placebo, conscious or subconscious differences between the sound of your playback with and without the power device. It is not sufficient judgment itself but it is already a good start, the start that no one know to me power units can handle. For premature judgment a power device should be treated as a preamp:  http://www.goodsoundclub.com/Forums/ShowPost.aspx?PostID=2589 Rgs, Romy the Cat

Antonio J. wrote:

The electrical supply in my building (I live in an 11th story of a 13th stories building) is very bad, as is in the whole area, which in spite of being residential, has 2 big hospitals around that probably have huge consumption. I have a dedicated line from breaker to the outlet, but I can't have it made from the building's input. In spite of this, I suffer huge voltage swings ranging from 210 to 224V.

Which is not really a big deal. The slow voltage fluctuation is NOT something that screw up sound. Sure, if your circuits do not use stabilization (most of SS lo voltage front-end do) then it would offset bias of you tubes moving then in different operation point. I do not recognize is as a big problem.

Antonio J. wrote:

This caused problems with some gear, not only "sound" ones, but also some devices having big DC offset at its output.

Also, not a big problem as well. If you use EI transformer and the transformer with oversized current then they do absorb DC offset.

Antonio J wrote:

I fixed this using a quite big industrial grade voltage stabilization unit, which uses two transformers and a voltage stabilization circuit. It can deliver 1000VA continous and can be delivering up to 4000VA for several minutes before shutting off. This changed the situation and now I have way more stable voltage from 228 to 232V at any moment I measure. The whole system runs through this device. This is just a voltage stabilizator, but not a full new sinewave regenerator, and for sure it doesn't decouple the system from the electrical grid as the APS or the Kemp would do.

Hmmmm, it is controversial and all depends of what kind voltage stabilization circuit your voltage stabilization unit has. If it is SS voltage stabilization then it is one mater. If it is resonance stabilizer (most likely) then it is a total different story. The resonance stabilizers have transformer and cap in the secondary where inductance and capacitance create a 50Hz resonance that actually re-generate a new sine-wave. Those transformers (they call constant voltage transformers) not only generate voltage but they also hugely defeat all line noise and so on. I had 3 large industrial resonance re-generators, including 2 of Sola transformer. They surely do “work”, the quality of sound they produce is totally different story.

Antonio J. wrote:

Soundwise I found this device very transparent, I mean that I wasn't able to determine if it changed a bit the sound performance of the system on good electricity days.

Congratulations, can you name the brand and model of this unit.

Antonio J. wrote:

On the other hand, this stabilizator of mine seems to be sensitive to the type of load,

Antonio J. wrote:

Of course I could remove the stabilizator from the system and just trying the Kemp as you suggest on a "good day", but then I fear I'd get back to the swinging voltages and DC offset on the units which weren't receiving their feed through the Kemp. Even on "good days" the voltage is swinging

If you use a devise like Kemp, APS, PS Audio, Acuphase  or any other true regenerator and the regenerators do work proporly then you do not need to use any supplementary stabilizers.

Antonio J. wrote:

You can find a brief description here: http://www.salicru.es/index.php?id=1678&L=2 My unit is a RE-1009 2T, which means has double transformer, but it's not the extra noise filtering model which they call NS. Looking at this I'm quite sure it doesn't regenerate a 50Hz sinewave. When I bought it I was using a SS power amplifier which was DC coupled, so the DC offset due to the voltage swings on the preamp, caused the woofers to move back and forth like bewitched. Sometimes it even caused the power amp to get into protection mode. The stabilizer solved this issue perfectly. Now I'm using different gear, then the stabilizer is not really as necessary as it was then, but since I don't find any shortcomings that I can blame on it (remember I'm not a knowledgeable listener nor my system has the resolving capabilities others have), I keep using it. Still I can notice when electricity is in a good or a bad day. I believe that a good regenerator that keeps voltage stable, decouples system from the grid and delivers a pure sinewave no matter what load you put in it, would be a very interesting thing to try. But all those devices are expensive and I really can't afford a trial and error merry-go-round to fix the power issues. As a toy the Kemp looks fun, those frequency and crest factor controls suggest that one could find a good working point to take the system's performance somewhere else. Deciding if that somewhere is any worth is completely another matter. Thoughu I suspect it's not transparent to good electricity from the outlet if any different point than 50Hz (60Hz in US), 0% crest factor is used. The 75w top power is also a big shortcoming, if I spend more than 1500 euros in a power regenerator I'd like to be able to use it for the whole system. Another feature that I find questionable is the balanced power thing. Audio circuits have a common leg which shouldn't carry any active signal other than the one generated by the own device. Why using it to get half of the voltage you need? The APS would be more interesting, but those reliability issues, the chance that sound results aren't the expected ones, and being the manufacturer in the USA and myself in Europe, makes it an uncertain choice. Moreover a unit for European market is different from a unit for the US, who knows how it would behave here. I tried a PS Audio and I didn't like the results. Kind of trendy fashionable hifi sound that many acquaintancies I have over here do like. Haven't tried any other regenerator, then my experience is very limited. Regards.

http://www.salicru.es/fileadmin/apps/descarga/fichas/SAI/Ficha-SLC-LINK_5000_%2801%29.pdf

They claim that “Sinewave shape is suitable quality for the loads”. I wonder it is it what the unit dos or juts a marketing claim they brainlessly made.

Still, behind everything there is always a consideration about the quality of sound that those units produce. The folks from SALICRU would not even understand what you are asking them if you approach this unit from sonic point of view. The APS folks do understand what they might be asked … they just need to learn to be able to answer the questions and the demands… :-)

BTW, there are very many similar to APS power regenerators on the market that are not optimized for audio. It is highly possible that the problem that APS experiencing now are very typical for all “no transformers, class D” regenerators. The APC double conversion regenerator that I have fucks up sound even more then APS.

As far as I know APS is the only companies that are trying to accommodate “no transformers, class D” regenerators for audio applications. I am sure would like to see 50 companies doing the same, competing with results. Do you see them? I do not. I was trying to encourage Paul from PS Audio to pay attention to this direction but he is busy stuffing audio houses with this new “class AB” Power Plant.  I think then, in a year or two he will introduce the “Revolutionary, exclusively by PS Audio” class-D Power Plant… BTW, it does not mean that it will sound better then APS unit….