John Curl's Blowtorch preamplifier part II

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We have a standard for home audio, and it used to be RCA, almost exclusively. Really high quality RCA connectors are pretty darn good, and good enough for just about any single ended application. About 35 years ago, Mark Levinson experimented with Fischer or Lemo connectors, much to everyone's dismay, because then only Mark could supply the interconnects, or else someone had to make an adaptor which just added more connections in the path.
Naim went to BNC connectors, and that had similar problems as Lemo connectors, being incompatable to the vast majority of commercial interconnects.
Of course we used XLR connectors for pro and balanced inputs and outputs, they have been used for many, many decades, but most consumer audio, especially tubes, was single ended, so the XLR connectors were redundant and wasteful by taking space. Also, the early Switchcraft and Cannon models were not that well made. I first used them at Ampex Audio, 44 years ago, in earnest, I still have a bin full.
 
Really? I always thought that real hi fi was about listening to your favorite music. I can hear propaganda on my portable radio, as I am doing at this moment.
For me, improving audio is always a struggle. In the last 20 years, since Vendetta Research closed its doors, I have designed dozens of audio products. Power amps and preamps, mostly. Most are OK, some are better than others. Each of these products try to follow my essential design directives that I gave to Parasound about 20 years ago. For the most part, they have been followed. When they were ignored, the product often got into trouble, and I was sent in to fix it.
Only the CTC Blowtorch preamp, has everything that I could do to make it as close to perfection as possible. It is my only 'keeper' audio product, except maybe for my Marantz 10 tube tuner, once I get it working again. The rest are audio 'tools' designed to do a job, and are replaceable with similar products. For example, my Parasound HCA-2500 power amp will soon be replaced with a new Parasound A21 power amp, so that I can live with it for awhile. Only 20 miles separates me from it, at this time.
 
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Audio industry Scott was a driving force when cinema and radio were major forces of propaganda. It's all about political and economical power.

Actually it was cinema that drove sound. The first Western Electric cinema sound systems used a single triode amplifier, with a bias pot and meter on the front panel, mercury vapor rectifiers were mounted in a different case outside of the projection room. The dual woofer horn was molded into the plaster wall behind the screen and was full screen size!. A "receiver" or what we now call a compression driver drove the high frequency curved horn. Passive crossover was used of course. The instruction manual not only told how to operate the equipment but also included helpful tips, like collect the money before atarting the show and always start at the same time each day.

Now Western Electric got the head start on this because they already made amplifiers and the "receivers." I have actually seen all of this equipment in a 1929 movie projector booth. I never got to see the woofers to see if they were electro-dynamic or even moving coil.

Then during the great depression a WPA (US government make work projects) project was to hire mathematicians to compile numerical charts of filter performance for all of the expected filter types that could be used. These were also done for not just frequency and LC values but also for source and load impedances.

Now the telephone was an outgrowth of the telegraph. The Samuel F. B. Morse system which was the first successful system was designed using Ohms law not the more commonly accepted at the time Barlow's law.

Now as to modern electronics it was the Crown DC300 that had Westinghouse trying very hard to make output devices that consistently match Gerald Stanley's requirements. Now US manufacturers did not consider consumer electronics as important a market as did the Japanese around 1970, so most of the audio driven semiconductor developments happened there.

The exception being Motorola which spent time developing transistors for Crown Audio. (Among others.)

So without the need for talkies much of what we take for granted would have been much slower in coming. Radio did improve much of the high power and high frequency limits in it's heyday, but that is a different story.

Now Scott as you know op-amps will never be good enough for audio so it would be silly to spend research time and money on such a small market part. :) !!
 
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diyAudio Member RIP
Joined 2005
[snip]
Now Scott as you know op-amps will never be good enough for audio so it would be silly to spend research time and money on such a small market part. :) !!

Yes, I'm reminded of the limo driver in This is Spinal Tap talking to the manager after the band members have rolled up the window to silence his discourse on Sinatra and the Rat Pack, referring to rock and roll as "a fad".

Brad
 
JC.
Back in the 70s I had a Naim system - for a short while. (It gave me a real listener's headache). I improved this slightly by using different interconnects. Naim collected the amps from me - along with all cable - for a warranty repair. It was returned with a new set of naims own cables but they did not return my - then - very expensive cables. This resulted in a conversation with Julian Vereker in which he refused to return the cables. This led to a row and he eventually did return them - but cancelled the maker's warranty. [They did back then have known troubles with certain cables such as the Polk ribbon woven speaker cables.]

Simon7000:
Good to have the WE information. We used their 15" drivers in a system and also used . The great reliability - for which WE equipment was famous - was I believe due to the fact that they rented their systems to end users on a full maintenance lease. Consequently their components and designs were made with low maintenance costs as a prime consideration.
 
'Alexander Nevsky', what a piece of propaganda!

Exactly! It was made by direct order of Josef Stalin when Hitler's armies at the beginning of WW-II were moving very fast eliminating any hope to stop them...

Pardon, my bad: actually it was shot in 1938 before WW-II, but when the war started Stalin ordered to show it everywhere.
 
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There is a difference between thick coated gold and soft gold.

No there's not. 24k gold is very soft, whether it's plated thick or thin.

Most connector gold is most properly hard gold.

Yes, which is gold alloyed with nickel or cobalt.

Still, nickel is avoided as an interface in the more expensive versions of the same connector.

So they're moving the nickel from the connector and instead mixing it in with the gold.

Nice sleight of hand.

se
 
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