[R-390] [OT] Acetone [WAS: How are your knobs?]

[Roy Morgan]

On May 19, 2014, at 11:50 PM, Charles Steinmetz <csteinmetz at yandex.com> wrote:

> OT now, but a very interesting sub-thread.

And here is a note that classifies as a sub-sub thread, with direct reference to the Infamous 807 transmitting tube, which rightly gained a very robust reputation far and wide in the world of transmitting, and later in audio amplifiers.*  The thread on the Glowbugs list:
RE: [Glowbugs] THE INFAMOUS 807
ranged far and wide to include use of an 807 tube modified to be a beer quaffing vessel,** and a discussion of the history of beer making and great praise for the current upsurge in micro-breweries here in the US.  This leads me to a tale about acetone:

> It seems to be uncontroversial that (unlike aldehydes) ketones are difficult to polymerize in general, and the successful polymerization of acetone seems to require unusual conditions:

A long time ago now I took an evening class in Harvard Square on German Wines.***  We learned that some of the differences, and good qualities, found among wines was due to the aldehydes and ketones in the final product.  This does make sense to me because of all the different and variable ingredients, main and trace, in the grapes and overall process.

One evening the instructor opened a bottle of wine, poured a polite amount into a clean glass and sniffed then tasted it.  After a thoughtful and serious pause, she announced:

“This wine tastes like …. ….  acetone!”

Sure enough, it did.  We may have confused the tastes and smells of a variety of compounds with nail polish remover that we were familiar with.

R-390 related content:
Later that evening, I happily made my way back to my loft room in a factory building nearby, where I also worked as a repairer of film sound recording and playback equipment.  This often involved the 12AU7, 12AT7, and the occasional 12AY7 tubes that we find in our treasured radios and other equipment.

Long live the 12AU7 and 807, and their variants!

Roy

*I have a much-treasured 1950’s home brewed Williamson amplifier that uses two 807’s in P-P triode mode for an estimated 20 watts output through a legendary UTC LS output transformer. It also has a couple of 6SL7’s and a 5U4.  The 6SL7’s should be 6SN7’s, though, and that may explain the case of microphonics it has.

**  See:  
> THE INFAMOUS 807
> 807 Beer Beam Power Tube
> 
> http://www.qsl.net/kb7rgg/radio/807/807specs.html

***The class was held near the then-famous Elsie’s Diner.  Elsie was very German and sold Löwenbräu beer.  One student asked for a “Lowen Brow” and she scolded him with:  “'Leuven Broi' young man, 'Leuven Broi’!"

Roy Morgan
RoyMorgan at alum.mit.edu
K1LKY Since 1958