The Plasmatron - more linear output voltage


From the website: "The Plasmatron provides a more linear voltage output."

Can someone explain why this would be beneficial as an ideal power supply is a sine wave? If it produced a sawtooth wave it could be more linear, but a sawtooth wave is what the cheapest transistors use.

A EE friend of mine is baffled by this claim. Can someone shed some light?
mceljo
I e-mailed Chris, at VH Audio, the importer for the Plasmatron and asked him to elaborate more as to why it (Plasmatron/Tyratron tubes) works. He held his cards very close to the vest as he stated intellectual property was in the process of being secured, thus the vague language. I auditioned the C6JA, and C3Ja tubed units, both were superb. I bought the smaller one and as I have written here on other threads, was very shocked by how much of a difference treating the AC signal makes. I have auditioned power cords from 100.00 to 8000.00 and none made this kind of difference. But, this is my system, and yours may respond differently.
This, to my ears, is a breakthrough product. An entirely different way of looking at how to treat AC. I have posted here, and Audio Circle, and have had cynics say how it borderline on voodoo, yet not evaluate one, or express an interest in evaluating one. Just a closed mind. I am not here to sell Plasmatron units, I HAVE No Vested interest, just makes more of a sonic improvement than any high $ power cord or line conditioning I have ever used. Follow your ears.....Plasmatech
I figure if it improves your system who cares how it works as long as it's safe and cost effective (which varies by individual). One thing that concerns me is the scarcity of the tubes and their cost although VHAudio reserves a spare set for each purchase.

How much experience do modern EE's have with this old technology? Maybe he needs to do some research. Tubes are probably not covered extensively in Electrical Engineering school although they probably were at one time. Plus this is a unique tube in that is filled with inert gas rather than a vacuum.
A friend of mine left his on 24/7 and he well past a year and no issues....a lot of tube hours. I turn mine off. No need to add tube hours. The tubes MUST be matched and VH Audio has the world's only known tube matcher for C3JA, C6JA.... (they designed and built one). Tube life is significantly extended. Plasmatech
Mceljo,

AC voltage is a sine wave, as your EE friend points out. However, it is expressed as a single value, e.g., 120 V or 117 V etc. That value is actually the root mean square (RMS) of the entire sine wave. One possibility is that the claim regarding linearity is with respect to the RMS. If the AC is linear, it is not AC, it is DC.

RJA, I don't know how much about tubes might be taught in current schools. In a sense, it is irrelevant. A good program produces graduates who are self educators, not just people who can regurgitate what one of their professors said 16 years ago.

Chris is a straight shooter. I have bought enough stuff from him that I trust what he says. Plus, there is a 14 day trial. If my life weren't in a complete state of flux, I would give one of these a try myself.
The assumption on this board is that EE's know everything there is to know about audio. Excuse me if I disagree.
"How much experience do modern EE's have with this old technology? Maybe he needs to do some research. Tubes are probably not covered extensively in Electrical Engineering school although they probably were at one time. Plus this is a unique tube in that is filled with inert gas rather than a vacuum.
Rja (Threads | Answers | This Thread)"

The real question is "How much experience does an EE have in designing high end audio equipment?". The only EE's I trust are the ones who put their money were their mouth is, and design the audio equipment I buy. Who cares what all the other ones say?
Plasmatech, which high $ power cords and conditioners have you used? Needed to put your comment in context.
The term "linearity" is often bandied about without a clear indication of what it is that varies in a linear manner with respect to what. Varying in a "linear manner" meaning that one variable varies in direct proportion to another, so that a graph having one variable as the vertical axis and the other as the horizontal axis would be a straight line.

In this case I would feel certain that the reference to linearity has nothing to do with the waveshape of the AC.

Here is the complete relevant statement from the vhaudio website:
First developed in the 1920's, Thyratron tubes are essentially gas controlled rectifiers. Different from typical vacuum tubes, gas-filled Thyratrons are capable of handling much higher current than their vacuum tube cousins, and this is one of the key attributes to their usage in the Plasmatron. The stunning blue plasma glow is created by ionized, xenon gas.

The Plasmatron provides a more linear voltage output by adding negative resistance to the power line source impedance. But that’s ‘EE-speak’... What that really means is: the voltage supplied by the Plasmatron won’t drop. In fact, it can actually go up, when the load is increased. Need more. Get more.

The Plasmatron is an AC power supply for source components.

Here’s what it’s not:

It is not a power conditioner.
It is not a spike or surge suppressor.
It is not a battery back-up.
It is not a power regenerator.
It is not a ‘filter’, in the conventional sense.
I would infer from this that it is a sort of a voltage stabilizer, which prevents the AC voltage from sagging down as load current increases, as would normally happen to some degree. The reference to negative resistance being equivalent to the statement that voltage may actually increase to some degree as current demand increases.

So to the extent that the device minimizes fluctuations in voltage that would normally result from fluctuations in current demand, it would seem that what is being linearized is variation of AC voltage as a function of time.

I have no idea, though, what all this may mean with respect to the likelihood of sonic benefit in most systems. I would note, however, that power amplifiers operating in Class AB or Class D generally have by far the greatest fluctuation in current demand among audio components, while also noting that power amplifiers are omitted from the list of components for which the Plasmatron models are recommended. Due undoubtedly, at least in part, to the somewhat limited load capability of the Plasmatrons.

BTW, in case anyone is interested, here are datasheets for the C3J and C6J Thyratrons. They are "grid controlled rectifiers," meaning that they rectify by switching the tube between conducting and non-conducting states via a control voltage applied to a grid in the tube, rather than by the more usual rectification process of a diode tube or diode semiconductor (which have no grid or other control element, and rectify by virtue of being able to conduct in only one direction).

Although of course rectification implies conversion of AC to DC, and obviously both the input and output of the Plasmatrons are AC. So I don't think it's possible to determine how the Thyratrons are being utilized in the design without further information.

Regards,
-- Al
Almarg - I had hoped that you would post.

I certainly don't consider my EE friend the end all for audio design, but he does have some experience with amplifier design and enjoys audio as a hobby as well. EE's certainly don't know everything, but are far more likely to see through gimmick marketing (not intending to use this product as an example) in a market where the average consumer know little to nothing about how the equipment actually functions. Buzz work bingo is good enough as long as we believe that it sounds better. My friend has specifically mentioned Krell as a company that uses scientifically correct and sound marketing where a EE can truly appreciate something g about the equipment. This isn't the norm.
Ptss, in response to your question, I have listened extensively to Cardas Golden Ref power cables as well as Audience. Shunyata Anaconda, Synergestic, and others, etc.
Power conditioning has been Bryston Bit20, Gray Substation, PS Audio Powerplant, Synergestic Power Cell, and others. One of the best combinations was the Plasmatron plugged into the Gray and PS Audio. Pushed the package forward substantially.
Negative differential resistance would be the better term, since it has to have some resistance in order to produce negative resistance change. Fluorescent tubes are also a negative resistance devices.

I cannot see how this device would help with gear that already has built in voltage regulators - pretty much any device other than power amps, but today many power amps have SMPS including half of class D amps and some class AB amps like the newest high power amps from Rowland. Perhaps resistance of this device have some filtering effect reducing power line noise.
"My friend has specifically mentioned Krell as a company that uses scientifically correct and sound marketing where a EE can truly appreciate something g about the equipment."

Your friend might want to re-think that one. If there's one thing we know about Krell's marketing, its the slogan "un-phased by any load". They built their business on that phrase. The problem is that its a flat out lie. There's no amp that's un-phased by any load. If that were true, they wouldn't be making amps that put out different amounts of power. Based on their marketing claims, there would be no need to.
Krell is still hanging on to that idea that tube preamps produce DC at their outputs, which is absurd. Not impressed.