Good advice. However even past members posts are copyright of WBF and are part of the WBF heritage. IMO past written posts on a subject can always be debated.
Isolation Transformer and Balanced Power versus PS Audio Regenerator
- Thread starter Ron Resnick
- Start date
Good advice. However even past members posts are copyright of WBF and are part of the WBF heritage. IMO past written posts on a subject can always be debated.
Again, I am addressing AC power systems from an objective perspective. Most we have on mains quality high-end is anecdotal, I am always interested in direct people own opinions, not indirect reported opinions.
My apologies, I will not address your false claims in the post.
If you want the technical answer, there's quite a lot of difference. To your last question, to cut to the chase, the answer is 'no'.
An isolation transformer is purely passive- no active devices.
A regenerator typically uses a 60Hz oscillator driving a power amplifier, which in turn drives a transformer whose output is the output of the regenerator. This allows the designer to have control over the distortion at the output, since feedback can be looped around the amplifier and transformer. A passive device has no such means so typically is higher distortion insofar as the AC line feeding your equipment is concerned.
Note there's no need for a switching supply or inverter, although these things can be used in a regenerator. Class D has good application in a regenerator too.
I built a regenerator using an old Bogen 100 Watt tube amp (using 8417s), driven by an old HP tube sine oscillator. The output was used to drive a tape recorder, which used a synchronous motor for the capstan drive. Such motors are locked to the line frequency so you can see where this was going- I used it to create variable speed as a studio effect.
This statement is false. Existing noise on the line is not eliminated by using nothing to eliminate it. You may have experienced more noise by using some kind of isolation transformer or the like; if you load most transformers past about 50% of their current rating, distortion at the output increases according to formula. The result can be a 5th harmonic which is particularly pesky in audio equipment, causing transformers to run hotter, more 'diode noise' and things like that. It might appear that getting rid of the AC power devices might be better, but if you run equipment that actually does the job properly it can be even better than that. This also based on experience but engineering as well.
We will just have to agree to disagree then. I know folks with Puritans, regenerators that cost that of a nice vehicle and Shunyata products that still are effected when other noise abaiting devices are used before, in or after the unit. I have experienced this myself first hand in multiple high end systems.
I have yet to come across any device that eliminates all noise. I wish not to get into an argument or even debate this. I am just relaying what my experiences have been, based upon what these ears tell me and have taught me over the years. If you want to believe otherwise? I have no issues with that at all, and I'll just leave it there. The only thing else I will say is this. My experience has taught me that my statement is not false.
Tom
I have yet to come across any device that eliminates all noise. I wish not to get into an argument or even debate this. I am just relaying what my experiences have been, based upon what these ears tell me and have taught me over the years. If you want to believe otherwise? I have no issues with that at all, and I'll just leave it there. The only thing else I will say is this. My experience has taught me that my statement is not false.
Tom
I don't understand this comment. I get doing nothing fixes nothing. And I get missusing or improperly applying a Iso Transformer will actually create more noise.
I thought the comment Tom made was no filter eliminates all noise. I would agree with this. Even my basic Fluke scopemeter shows low order harmonics walk right through every Shunyata, AQ, Isotek, Torus filter I have measured. And the fact that the frequencies they do filter well show measurements of say a 80db reduction in noise says they didn't eliminate all the noise. Much of it at certain frequencies, but not all.
When you employ a small sample size in observations its highly likely that conclusions drawn from such will have a high degree of error; that is a particular form of logical fallacy.
When it comes to AC line noise, measurements can be particularly useful. Without having done any, its very possible that some of the equipment mentioned (as I alluded to earlier) will in fact make things worse.
I've stated this elsewhere, but IMO/IME a lot of AC line products offered to high end audio are so much junk and no surprise someone like yourself might come to the conclusion that they make things worse, simply because they are.
What I was suggesting is that you try equipment that is actually known the make the line quieter and (more importantly) lower distortion. I've not found that much out there offered to high end audio that really does the job. The PSAudio regenerators seem to be the best. But if you look beyond high end audio, there are conditioners made that actually do (or did) work. Elgar comes to mind; in the 1970s they made a range of power conditioners that were quite effective, with high current capacity, guaranteed distortion at full load and AC line Voltage regulation.
Anything passive is going to be a filter of some sort, unless its a transformer of some kind, in which case its likely to introduce distortion.
So I'm not saying you are wrong- simply that your statement was. I suspect your experience of limited sample size is correct- I've experienced that many times myself. Our OTL amps draw enough power that most 'high end audio' AC line products are instantly in over their heads, so as a result I often recommend people plug the amps straight into the wall for best effect, unless they are willing to invest in a proper AC line conditioning.
Good point- there are two ways to interpret his words.
However if you have a proper line conditioner you may find that it can do quite a lot more mitigating line noise than you may have previously thought possible. You might have a go with one of those Elgar conditioners I mentioned, although in my experience they usually need refurbishment when you find one in condition worthy of giving it a go.
I'm totally happy with Torus. I know how to size them. If someone were to have a massive power amp, you can use a single 100 amp high output core to filter in front of it. No amplifier will draw enough current to distort that core.
My fascination and ruminating on battery/inverter power is more based in a solution for someone that has no means to modify low quality builder grade circuits in the listening room. And, it may perform at a very high level.
I believe there are many filters being produced that can work well on front end, signal, data bckbone equipment. But you have to be careful to not "over filter". Or shall I say, create a sound that might sound like noise was removed, but musicality suffers.
My fascination and ruminating on battery/inverter power is more based in a solution for someone that has no means to modify low quality builder grade circuits in the listening room. And, it may perform at a very high level.
I believe there are many filters being produced that can work well on front end, signal, data bckbone equipment. But you have to be careful to not "over filter". Or shall I say, create a sound that might sound like noise was removed, but musicality suffers.
I've been using the Torus rm 20 and have the P20 ps audio regen on demo. I took some measurements today from the outlets (with Fluke 345) and got some results that seem strange -- (or I don't know how to interpret.)
The sine wave and harmonics that the Fluke measures were the same from Wall or Torus. Not surprising, given we know lower harmonics pass through most filters. The Torus, as I understand, addresses higher frequencies.
The P20, despite showing a perfect regenerated sine wave, also showed 5.5% THD. This is higher than the Wall and Torus and of course much higher than the readout on the P20 of .1% THD.
And for more confusion, despite the P 20 higher THD than the Wall or Torus, the Flukes' Harmonics graph showed less distortion spectra than the Wall or Torus.
Maybe the additional harmonics on the P 20 are hidden where they don't show on the graphical distortion profile?
In the pictures below, the first two from left are Torus and the last 2 are P20
The sine wave and harmonics that the Fluke measures were the same from Wall or Torus. Not surprising, given we know lower harmonics pass through most filters. The Torus, as I understand, addresses higher frequencies.
The P20, despite showing a perfect regenerated sine wave, also showed 5.5% THD. This is higher than the Wall and Torus and of course much higher than the readout on the P20 of .1% THD.
And for more confusion, despite the P 20 higher THD than the Wall or Torus, the Flukes' Harmonics graph showed less distortion spectra than the Wall or Torus.
Maybe the additional harmonics on the P 20 are hidden where they don't show on the graphical distortion profile?
In the pictures below, the first two from left are Torus and the last 2 are P20
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Against non-linear loads, such as switching power supplies and frequency converters for motors, an isolation transformer is no use; it simply passes through the winding barrier. The only solution is a compensation system (inductors and capacitors) to initially maintain a stable phase position. Unfortunately, this is only imposed on large companies by the grid operators. In Germany, up to 8% THD is permitted before complaints are allowed. In that case, only steep-edge filters starting at 1 kHz helps then you are safe from high frequency garbage, but frequency converters usually run between 25hz-600hz so nothing helps. The so-called reactive load (motors inductive) on the mains voltage increases THD immensely.
The only thing an isolation transformer is good for is that it operates unearthed on the secondary side, eliminating the need for mains plug polarity or phasing out of the devices.
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Isolation transformers are excellent for RF noise.
I personally don't know what noise is most damaging to audio playback. It may be the power supply in your equipment does a good job with 3rd, 5th, 7th etc noise, but not so good with RF.
Filters do something. You hear all of them. I personally find Torus most always improves the sound without detriment. My perception is many others find Shunyata does the same. But dang, Elliot anounced the new Shunyata for $15,000. You could get 3 x RM20 for that money. 1 for each amp and 1 for the front end. A pretty optimum setup. You could also get 2 AVR RM20 that are the only units, not UPS, that adjust the voltage so it remains 120 during sags and swells. Or you could get a WM90BAL that has 5 x 20A output cores and easily powers a massively system. If you saw the Rhapsody Florida or Texas video, I forget which one, the owner has 2 and powers all his rooms off them.
I would still bring non filtered citcuits to the room . You always want options. That is how my room is setup.
I personally don't know what noise is most damaging to audio playback. It may be the power supply in your equipment does a good job with 3rd, 5th, 7th etc noise, but not so good with RF.
Filters do something. You hear all of them. I personally find Torus most always improves the sound without detriment. My perception is many others find Shunyata does the same. But dang, Elliot anounced the new Shunyata for $15,000. You could get 3 x RM20 for that money. 1 for each amp and 1 for the front end. A pretty optimum setup. You could also get 2 AVR RM20 that are the only units, not UPS, that adjust the voltage so it remains 120 during sags and swells. Or you could get a WM90BAL that has 5 x 20A output cores and easily powers a massively system. If you saw the Rhapsody Florida or Texas video, I forget which one, the owner has 2 and powers all his rooms off them.
I would still bring non filtered citcuits to the room . You always want options. That is how my room is setup.
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Some people say that RF noise goes from 3 kHz (kilohertz) to 300 GHz (gigahertz) . IMO unless we specify bandwidth such general claims are ambiguous.
What frequency do TV and cell phone, wifi and Bluetooth operate at? That would be the majority of RF
I took more just new, with similar results.
First two pictures from top are P20 measured from pos and neg dup outlet
Next two are Torus RM20 measures from pos and neg at duplex outlet
Last two are Wall measured at pos and neg in sub panel.
I wonder what accounts for the Fluke measuring 5.4%. and the harmonic spectra showing 3rd order harmonics which don't reflect their specs or front panel display.
And to add more confusion, the P20 sine wave is perfect on both the Fluke and the front display.
I'm not qualified to make any conclusions other than the Wall and Torus measurements mostly make sense to me. The P20 measurements raise questions (such as what is the pertinent the reading, 0.1 or 5.4?).
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...do the waveforms appear approximately the same (as depicted here) with a different time interval on the display grid?
...yes, I noticed they are uniformly at 5ms. I wondered if they *appear* different with a change in the time interval depicted on screen. Like you, something seems unusual to me. I don't use these devices regularly for many years now, so I am no help re: methodology, etc. Thank you for posting.
I’ll see if I can figure out how to look at them under different time intervals.
The strange thing to me is the dis-correlation between the PS audio, smooth wave and the high THD.
The measurement at the sub panel is certainly better than either of the conditioners.
But this doesn’t take into account, at least for the Torus, of the high frequency, filtering it supposedly does.
I think my next step, should be listening to the system without any filtration.
I’ll see if I can figure out how to look at them under different time intervals.
The strange thing to me is the discorrelation between the PS audio, smooth wave and the high THD.
The measurement at the sub panel is certainly better than either of the conditioners.
But this doesn’t take into account, at least for the Torus, of the high frequency, filtering it supposedly does.
I think my next step, should be listening to the system without any filtration.
The end result is THE only thing that matters. Trust your ears.
Tom
Tom
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