AVR Freaks

 

While remaining at 240v, of course. At the same time, EU distribution is also nominally 230v +10/-6% which also - amazing! - means that 220v here also meets the same spec.

 

A UK toaster on EU mains is noticeably slower than it was in the UK, as is a UK kettle...

 

Neil

As a consequence (back in 80's) ordinary bulbs were extraordinary quick to burn, they were not adapted, not yet.

You do know about the "mafia" conspiracy to  limit bulb life??    If you were caught making bulbs that lasted too long, you would hear from "the boss" and get in very big trouble 

 

There were continual reports of cartel members’ attempts to restore the burning time of their bulbs to the old levels in defiance of the watchful eyes of Phoebus. At one point, some members surreptitiously introduced longer-lived bulbs by designing them to run at a voltage higher than the standard line voltage.

 

it is of the greatest importance that we do not sink back into the same mire by paying no attention to voltages and supplying lamps that will have a very prolonged life.”

 

https://www.everlumen.no/the-gre...

 

 

ON 23 DECEMBER 1924, a group of leading international businessmen gathered in Geneva for a meeting that would alter the world for decades to come. Present were top representatives from all the major lightbulb manufacturers, including Germany’s Osram, the Netherlands’ Philips, France’s Compagnie des Lampes, and the United States’ General Electric.

 

These companies colluded, it turns out, to engineer incandescent lightbulbs with dramatically attenuated life spans: over the next years, bulbs that once burned some fifteen hundred to two thousand hours were made to last for only a thousand, thus enabling every company in the world to sell more bulbs and artificially inflate prices. The ruse lasted until 1940, and it was surprisingly sophisticated in its execution; the companies involved made “very strenuous efforts … to emerge from a period of long life lamps,” as one executive wrote.

 

The cartel took its business of shortening the lifetime of bulbs every bit as seriously as earlier researchers had approached their job of lengthening it. Each factory bound by the cartel agreement—and there were hundreds, including GE’s numerous licensees throughout the world—had to regularly send samples of its bulbs to a central testing laboratory in Switzerland. There, the bulbs were thoroughly vetted against cartel standards. If any factory submitted bulbs lasting longer or shorter than the regulated life span for its type, the factory was obliged to pay a fine.

 

 

Interesting legacy design issue I hadn't thought of; an interesting observation about what happens when you *don't* design things correctly and - major manufacturer or not - run components at or beyond their specified voltages. I guess the safe way to do this would be to use a rectified and controlled DC 6.3v for the heater voltages (that'd be high current, though) and probably the same - at high voltage - for the anode drives. It's been so long since I've designed anything so closely dependent on the mains voltage that I've not thought about this for years... probably the valve aficionados would complain about the presence of silicon in that iconic valve sound.

 

Neil

Oh don't get me started - follow me on Twitter if you want to know what I really think about the immigration/brexit/racism situation in the UK. 

But why don’t they use some sort of regulated power supply to drive the valves?

There are many misconceptions about Edward Van Halen’s primary amplifier used for recording. Rumors have abounded about the amplifier being heavily modified and some of these rumors were in fact generated by Mr. Van Halen himself (he admitted telling these stories to help generate business for tech friend Jose Arrendo’s shop). However, in truth according to our best knowledge, his amplifier of choice for recording, a mid-60’s 100 watt Marshall Super Lead, was primarily stock (Note: see studio diagram description for more info on this). Edward was adamant about getting his tone through the power tubes and consequently set all volume and tone controls on the Marshall to 10. He controlled the overall volume output in two ways.

First, he used an Ohmite Variac, a variable transformer that could lower or raise the voltage going into the amplifier (see photo for what a typical Variac looks like). Edward set the variac to approximately 90 volts, thereby reducing the amount of input voltage going to the amplifier (see the Marshall Super Lead article for more information about variacs and attenuators) and allowing the amp to run more reliably. A key element often not considered today when running vintage Marshall amplifiers is that many that were made for export to the U.S. were designed to run at 110 volts and current U.S. outlets run at 120 volts. As a result, while there has been much talk about the dangers of using a variac, in many applications, it obviously serves a benefit.