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Camy

I concur.

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I've never seen a chair with five legs. Have I lived in ignorance all this time? LOL. Having said that, I wish all too frequently for a five-legged chair to use.

I've had more than my share of four-legged chairs that wouldn't sit level, and I think a five-legger would be impossible to stabilize. Three legs seem the logical approach, and I wonder why we don't have more of those.

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Since design wise, the fifth leg would need to be either in the middle, or between two others, the pragmatic solution would be to deliberately make it shorter than the other four. So it would not make the chair wobbly on a average floor and be purely decorative.

Rather like the early multivalve radio that had, I think, two valves not even connected. The set was a TRF (Tuned Radio Frequency) and there is a practical limit on the number of valves as beyond it, more just make the set worse. So the set just connected up the heaters to make them glow, but the signal itself went nowhere near.

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Since design wise, the fifth leg would need to be either in the middle, or between two others, the pragmatic solution would be to deliberately make it shorter than the other four. So it would not make the chair wobbly on a average floor and be purely decorative.

Rather like the early multivalve radio that had, I think, two valves not even connected. The set was a TRF (Tuned Radio Frequency) and there is a practical limit on the number of valves as beyond it, more just make the set worse. So the set just connected up the heaters to make them glow, but the signal itself went nowhere near.

That's an easy one to solve, Nick. Old transformerless sets wired the filaments in series and put them directly across the mains line. We never had that problem in the U.S. as the mains are typically 110 volts not the 220 you use on the opposite side of the pond.

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The rule of thumb, and indeed the selling point, some 60 years ago was that the more valves (tubes) a set had, the better the quality.

This was true for a number of reasons, one of which was that the output stage was either single ended or ultra-linear with two valves in a push-pull configuration, with each valve delivering half of the wave form. Also the input might consist of one or two stages of amplification. Hi-Fidelity amplifiers such as the Mullard 5-20, or the famed Williamson design were examples of these configurations.

I should also mention that the number of valves can also be confusing because some valves have two separate stages in the one glass envelope.

The Westrex (and RCA) amplifiers almost exclusively used in Hollywood related cinemas even had doubled up on the number of output valves to ensure quality, reliability and power (40 watts). Smaller cinemas surprised me when I saw they had a one (huge) valve amplifier stage carefully matched to the horn loaded loudspeaker for an output of 3 acoustic watts, (Very loud those acoustic watts), and were used in cinemas of upto 5,000 seats.

With the introduction of solid state amplifiers using current amplification, instead of the voltage amplification of the valves, much higher current was needed to drive the speakers. The 1970 -80s were full of research and design which eventually gave us the huge 100-500 watt solid state designs which are common place today.

Please note that all the numbers for wattage given above are RMS watts. If you don't know what that means, don't worry, just look for RMS watts on the specification sheets of any amplifiers you are considering so that you compare like with like.

The nature of the difference between current power of the solid state designs and voltage amplitude of the valve designs is thought to contribute to quality differences between the two designs.

In any case, there are Hi-Fi enthusiasts who still experiment with valves, but solid state is probably more convenient for a similar result provided the connecting cables to the speaker are of sufficiently high quality and low resistance.

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It's amazing what one can learn on this forum! Five-legged and three-legged chairs, valves (a.k.a. vacuum tubes), TRF radios, scaffolders who purposely blocked satellite dishes, and morons who work for PC World.

All of this (and more!) resulting from wanting to high-five someone with a chair.

Life can be so very interesting. Bizarre, even.

Colin :icon_geek:

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