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AC to AC supply

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Aussie Mick View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Aussie Mick Quote  Post ReplyReply Direct Link To This Post Posted: 10 Apr 2018 at 1:29pm
Hi All,
The $64,000 question! Elevator, Reflex, Majestic and Proprii all have dedicated power supplies. Does that mean they’ll not benefit from power regeneration? My only other gear is the RP8 with a dedicated power supply, and my CD transport from Japan, for which I use a separate step down transformer. So, is there any mileage in me thinking about this?

Should I just be quiet and listen to music?
Mick.
Rega RP8 - Apheta 2 - Accession MC Enigma PS -Solo ULDE (Focal Utopia) - PS Audio M700 - Fical Kanta No2
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Post Options Post Options   Thanks (0) Thanks(0)   Quote RichW Quote  Post ReplyReply Direct Link To This Post Posted: 11 Apr 2018 at 8:32am
Hi Mick,
Whether or not your system will benefit from mains regeneration depends on how good
your incoming mains is & how many appliances share the mains circuit.
Some people insist that regenerators are never necessary - these people are often the ones
who sometimes state on certain forums that nearly all equipment sounds the same...Smile
People like Laurence above, with variable mains quality, may well benefit & hopefully
the AG500 will sort out his problem.
Majestic/Enigma, Accession MM & MC.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Aussie Mick Quote  Post ReplyReply Direct Link To This Post Posted: 11 Apr 2018 at 9:07am
Cheers. I suppose there’s only one way to really find out.
Rega RP8 - Apheta 2 - Accession MC Enigma PS -Solo ULDE (Focal Utopia) - PS Audio M700 - Fical Kanta No2
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Baflar Quote  Post ReplyReply Direct Link To This Post Posted: 11 Apr 2018 at 9:52am
Hi All.  Just quick thanks for your continued interest in my (mildly neurotic) attempt to control my ingrained disbelief in the improvements expected from investing in 'clean' AC!  I have been notified that the AC Regenerator will be delivered by 10:40 a.m. today Big smile ...  Stay tuned for an eventual bulletin.  Fingers, toes and knees crossed...

Lawrence.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Graham Slee Quote  Post ReplyReply Direct Link To This Post Posted: 11 Apr 2018 at 10:16am
Is mains electricity really all that bad?

It is noisy, or can be, but its harmonic (distortion) content has to be controlled within limits or some appliances could malfunction.

Nevertheless, a difference can be detected between mains AC and regenerated AC.

Regenerated AC requires the mains to be transformed and rectified to produce DC; then that DC is made to do an AC voltage, and a number of means are used. The AC is applied to a transformer and out comes 230V (115V in such as the US).

Still, the regenerated AC relies on the mains AC. No getting away from it.

To make the regenerated AC really clean means having a low distortion oscillator to produce the right frequency (50 or 60Hz).

It then needs a low distortion power amplifier followed by a transformer.

To do sufficient to power a hi-fi rig you'd want around 100 - 500 watts. Say your amp is 100 WPC you will need 200 watts just for that.

I recently made a turntable regenerator to supply a 3.5 watt motor using a pure AC waveform and transformer. The case, Era Gold size, gets hot.

Now think how much heat will be generated to do 100 times that (350 watts)?

Obviously this is a problem, but if you use PWM (pulse width modulation) the output transistors can be made to switch rather than amplify, and in doing so will run appreciably cooler.

The emerging waveform is still a nice sinusoidal AC because the transformer "ignores" the high speed switching required for PWM.

However, the transformer primary is handling the high speed switching, and producing lots of spurious noise, and that noise is induced into the secondary (the output), and will be in the MHz region, rather than the lower frequency noise sometimes seen with mains (on an osciloscope).

Some of that noise goes back into the mains, and some is emitted as airborne noise, and some is induced into other items.

Basically you have a switched mode power supply.

Then there are the much more rugged (and cheaper) type that just switch a 50 or 60 Hz square wave into the transformer. And I doubt they will pass any EMC test.

Now, I don't want to try and dictate what people should use. My purpose as a member here is simply to inform others about things I know or have experienced.

But, unless you can find a pure sinewave regenerator, and a true one will be expensive, big, heavy, and will run hot; then you will be using switched mode.

And switched mode in my opinion doesn't bring an improvement. It will bring about a difference, as most things do.

If your mains is so bad as to cause malfunctions then obviously anything is better.

That none should be able to buy or sell without a smartphone and the knowledge in how to use apps
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Baflar Quote  Post ReplyReply Direct Link To This Post Posted: 13 Apr 2018 at 11:28am
For those still interested (!) - here's my early verdict on installing the PowerInspired 500w AC Regenerator.

Headline: Does it bring an improvement?  Yes, it does.
...not a wham-bam-make-you-shout-wow! improvement, but several subtle improvements.  Only serious tests so far have been listening to CDs, with a couple of checks against vinyl copies of the same music.  For some reason beyond my understanding, there is a clear improvement in channel separation/ sound stage, which is very nice.  Beyond that, there is an improved clarity and presence to bass instruments.  I listen mostly to classical and old pop (when I'm in that sort of mood).  The massed double basses in the final movement of Janacek's Sinfonietta sound great: up to the standard of the famously exemplary Decca vinyl copy of the same.  There is a slight improvement in detail on Tell Him by Billie Davis on CD, which previously fell well short of the vinyl copy.  Vinyl still wins overall for sweeter treble sounds.

I've played one piece of classical from minidisc, and couldn't really confirm any improvement: jury still out on that.  On vinyl, the really big improvement was installing the Slee phono pre-amp last year.  I'm not convinced that the Regenerator has added to that.

Verdict:  An expensive way to bring an improvement, essentially to CD reproduction, but probably justifiable in opening up renewed pleasure in listening to music via that source, and given that this is definitely a once in a lifetime purchase.  If you're curious about the Output from the Regenerator, mine fluctuates moment by moment between about 229.7v and 230.6v; PowerInspired promise a pure sinusoidal wave output; the equipment is heavy; it doesn't run hot and the fan is silent.

Cheers!
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Post Options Post Options   Thanks (0) Thanks(0)   Quote ICL1P Quote  Post ReplyReply Direct Link To This Post Posted: 13 Apr 2018 at 5:33pm
Interesting. Thank you. I only very occasionally think that mains quality might be messing things up of an evening, so I won’t be rushing out, but it’s interesting to hear the experiences of others.
Ifor
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Reflex M & ACCESSION M, CuSat50, Majestic DAC, a Proprius pair.
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