PurePower 3000 AC Regenerator Review

[wwenze]

No, they don't. They all (including linear power supplies) will only draw (short duration and high) peak currents near the top of the sine. This is what causes the flattening of the top of the sine.
All AC to DC converters work this way.

Only things like simple heaters and incandescent bulbs draw a sine-like current.

Active PFC.

 

[solderdude]

PFC is about the phase of the drawn mains current, not so much the shape of the current being drawn over the entire duration.
This is to ensure most current is drawn at the peak of the mains voltage.
Even with PFC the drawn current from the mains still are short peaks.

 

[wwenze]

PFC is about the phase of the drawn mains current, not so much the shape of the current being drawn over the entire duration.
This is to ensure most current is drawn at the peak of the mains voltage.
Even with PFC the drawn current from the mains still are short peaks.

Active Power Factor Correction Verification Measurements

Active Power Factor Correction Verification Measurements

www.tek.com

 

[solderdude]

Most audio equipment doesn't have (active) PFC.
The high power class-D most likely do have this in though.

In the pro world (PA work) PFC is much more common and/or required.

 

[dinglehoser]

I have 3 Cyberpower UPSs. I bought them because they were the only 1RU fanless sinewave units I could find. Every 2 years or so, batteries die. After getting tired of paying high prices for the batteries, I figured out how to buy the individual batteries for cheap and replace them for half the price. Alas, two of the units have failed in the 5 to 7 years.

I have an APC with Lithium battery that was discontinued. It was expensive but it is going on 5 or so years with no problems.

As a point of comparison, I have a >10 year old Eaton 5PX still (loudly) running on its original VRLA batteries. They still appear to hold >80% of their capacity - during a recent power outage, they ran an average ~200W load for close to an hour without shutting down (the battery pack is 432Wh and the deep discharge protection mode limits the minimum discharge SOC to ~50%). I think the sauce is in how this unit handles battery management, as it appears to perform some sort of algorithmic charge cycling instead of the dumb constant voltage most consumer UPSes use.

 

[kyuu]

As a point of comparison, I have a >10 year old Eaton 5PX still (loudly) running on its original VRLA batteries. They still appear to hold >80% of their capacity - during a recent power outage, they ran an average ~200W load for close to an hour without shutting down (the battery pack is 432Wh and the deep discharge protection mode limits the minimum discharge SOC to ~50%). I think the sauce is in how this unit handles battery management, as it appears to perform some sort of algorithmic charge cycling instead of the dumb constant voltage most consumer UPSes use.

Possible Eaton really has some secret sauce I'm unaware of, you have some sort of unusual sample that is outside of the typical bounds of VRLA, and/or the batteries Eaton are using are optimized for a much longer lifespan than is typical. The APC UPSes that utilize lead-acids which I have experience with (which are enterprise designs, not consumer) have typical battery lifespans of 3 to 5 years. And it's not unusual, if I push the battery replacement out to 5 years, to find the batteries have swelled and need a little coercion to extricate from UPS.

 

[dinglehoser]

Possible Eaton really has some secret sauce I'm unaware of, you have some sort of unusual sample that is outside of the typical bounds of VRLA, and/or the batteries Eaton are using are optimized for a much longer lifespan than is typical. The APC UPSes that utilize lead-acids which I have experience with (which are enterprise designs, not consumer) have typical battery lifespans of 3 to 5 years. And it's not unusual, if I push the battery replacement out to 5 years, to find the batteries have swelled and need a little coercion to extricate from UPS.

Thick plates and conservative cycle depth, probably. The cycling probably helps prevent sulfation. I doubt the sample itself is out of the ordinary - the pack consists of 4x bog standard 12v 9ah units in series.

 

[cst]

Hi All
I’m new here, but have relied on the forum for a long time. I have a particular situation that no one seems to talk about. And of course I am lookin for advice from all those who know far more about all things than I do.

Regarding AC Regenerators, I totally get that they do nothing to make audio sound better than clean AC out of the utility company. However, I live with off-grid solar — a large array and large battery power storage. It is a slick new system from LG. The problem os that the AC supplied by the batteries / inverter is lousy —steady 60hz but not a clean sine-wave. Ok for most things electronic, but its kept me from my audio system for several months. After installing the solar, my amp buzzes as if there is DC hitting the toroidal transformer. I’ve tried a DC Blocker with no change / no success. I’ve put in-line an old Topaz Ultra Iso transformer I have. It helped quite a bit but not completely.

So to you all, what about a AC Regenerator — just to clean up my crap AC out of the solar inverter? Seems like it might be the answer. Also, I totally open to learn of any thing that might help, DIY or otherwise.

My current thought (past a regenerator) is a line / load reactor in front of the Iso transformer. Or maybe two large 60hz motors mechanically coupled together where one is fed my crap AC, and in turn spins the passive motor (turned alternator) which creates new clean 60hz AC ( just kidding sounds cool )

Thanks for any advice or insights.

 

[kyuu]

Regarding AC Regenerators, I totally get that they do nothing to make audio sound better than clean AC out of the utility company. However, I live with off-grid solar — a large array and large battery power storage. It is a slick new system from LG. The problem os that the AC supplied by the batteries / inverter is lousy —steady 60hz but not a clean sine-wave. Ok for most things electronic, but its kept me from my audio system for several months. After installing the solar, my amp buzzes as if there is DC hitting the toroidal transformer. I’ve tried a DC Blocker with no change / no success. I’ve put in-line an old Topaz Ultra Iso transformer I have. It helped quite a bit but not completely.

So to you all, what about a AC Regenerator — just to clean up my crap AC out of the solar inverter? Seems like it might be the answer. Also, I totally open to learn of any thing that might help, DIY or otherwise.

Without knowing more it's hard to say that the AC regenerator won't help, but I would say it's extremely unlikely. Understand that the waveform you get from a utility is nowhere near a pristine 60Hz sine wave either. Unless there's something seriously wrong with what the inverter in your LG system is putting out, I doubt the issue is something an AC generator will help with.

As an aside, if it really is that bad then it's something LG or the installer should probably be addressing. No halfway decent system should have an inverter that puts out a seriously distorted waveform to the point that it causes issues with equipment.


For this buzzing, you've verified that it's coming from the amp itself and not any speakers? Are you able to plug the amp into another AC source to see if it buzzed there also? If it's the amp itself, you may need to adjust the bolts holding the transformer down or add some rubber gaskets or the like. Transformers always vibrate to some extent, but it's much more audible if it's being allowed to rattle against the case.

 

[cst]

Kyuu,
Thanks for the quick response. LG has sent out a team of engineers. they certify that the system is working with-in tolerances. I've talked to several solar people; inverters putting out noisy AC seems a common issue and acceptable because most appliances in the home transform to DC right away.
We have a small portable solar battery pack which causes no issue with the amp., but the fan is tooo loud to use as my power source. As I say, this has been a heck of a problem. Either I’m the only person with this issue, or no one admits to knowing about this.

To your question about the amp… the amp, a First Watt F3 (Power J-Fet) the buzz is both a physical buzz I should point out that the “buzz” is not like a typical 60hz ground problem. It’s really more of a ticking sound mixed with a hum. I thought perhaps there is DC hitting the toroidal transformer. But DC Blocker had no effect.

Yes there is also buzzing in the speakers. I have swapped out the F3 for an older Yamaha intageated amp and there is no negative sound at all, it just doesn’t sound beautiful like the F3.
Clearly the First Watt’s transformer / design is a sensitive circuit. But we love the F3, so we struggle on to find a solution. This is one of the amps that was built by Nelson Pass himself. They had the amp to make sure all was well. I have worked with one of his guys on the issue, their suggestion is to put a Line Reactor between the sound system and the inverter. Which is I think my next step.

P.S. FYI, here is a list of the other gear in the system — just in case it helps explain something.
First Watt F3, Bent Audio Passive Preamp (autoformer), old Burr-Brown DAC and Innuos server, a pair of older White 4400 Eq’s — all driving Tannoy 15” HPD’s. My space is small so there is never a huge load on anything.

Thank you so much for your comments. Every point of view helps me immencely.

 

[kyuu]

To your question about the amp… the amp, a First Watt F3 (Power J-Fet)

That's a, uh... "unusual" amp, to put it mildly. To each their own, but an amp that consumes 200 watts to output 15 watts, at most, is not something I would ever consider. Seems like it was made to be as inefficient as possible. I guess it doubles as a space heater when it gets cold, at least.

In any case, good luck with the line reactor.

 

[Extreme_Boky]

Kyuu,
Thanks for the quick response. LG has sent out a team of engineers. they certify that the system is working with-in tolerances. I've talked to several solar people; inverters putting out noisy AC seems a common issue and acceptable because most appliances in the home transform to DC right away.
We have a small portable solar battery pack which causes no issue with the amp., but the fan is tooo loud to use as my power source. As I say, this has been a heck of a problem. Either I’m the only person with this issue, or no one admits to knowing about this.

To your question about the amp… the amp, a First Watt F3 (Power J-Fet) the buzz is both a physical buzz I should point out that the “buzz” is not like a typical 60hz ground problem. It’s really more of a ticking sound mixed with a hum. I thought perhaps there is DC hitting the toroidal transformer. But DC Blocker had no effect.

Yes there is also buzzing in the speakers. I have swapped out the F3 for an older Yamaha intageated amp and there is no negative sound at all, it just doesn’t sound beautiful like the F3.
Clearly the First Watt’s transformer / design is a sensitive circuit. But we love the F3, so we struggle on to find a solution. This is one of the amps that was built by Nelson Pass himself. They had the amp to make sure all was well. I have worked with one of his guys on the issue, their suggestion is to put a Line Reactor between the sound system and the inverter. Which is I think my next step.

P.S. FYI, here is a list of the other gear in the system — just in case it helps explain something.
First Watt F3, Bent Audio Passive Preamp (autoformer), old Burr-Brown DAC and Innuos server, a pair of older White 4400 Eq’s — all driving Tannoy 15” HPD’s. My space is small so there is never a huge load on anything.

Thank you so much for your comments. Every point of view helps me immencely.

There's a dedicated thread to Pass Labs (and First Watt amplifiers and their clones) at diyAudio. Maybe people over there can help..??

 

[EERecordist]

This is a review and measurements of the PurePower 3000 AC Regenerator and Battery Back up. It was kindly drop shipped to me from the company in Canada. I am not sure of its cost. Old price lists show it at US $5000.
...
View attachment 453776

...

I work in the utility industry. We have a lot of inverters in the system. Inverters run on software. This is a poorly designed inverter at a very high price.

Just the breadth of the fundamental should be of concern. There is a theory that batteries "smooth things out." The batteries are before the inverter producing all the harmonic distortion/garbage. You can't compensate for fundamental garbage with inductors and capacitors after the inverter, though those can absorb the higher order harmonics.