[GreenKeys] Solder

Thu Nov 29 20:48:14 EST 2012

Richard,

 Actually it does.. Bob was a ham and he bought his first teletype machine from 
.. me.  Jack saw this machine at my house many years ago, with a climbing head 
reader and a tape stuffing bin.  I build it from brand new or refurbished parts 
given to me by someone at Michigan Bell.

 I was close with Bob and still remain close with his family.  One of his sons, 
I believe, monitors this list.

 You are almost 100% correct about all that history, so it sounds like you know 
something.  You are correct about the mics.  Most (all?) of Living Presence was 
done on 35mm magnetic film (Westrex).   I don't know about the consoles, but I 
know the mastering was done through a Westrex portable mixer.   Most of that 
equipment was passive with gain makeup amplifiers.  In fact there was a complete 
console in one of their studios, built by Western Electric, that was completely 
passive, including the equalizers, except for the mic preamps and the line 
output amplifiers.

Bob (or Wilma?) correctly determined through listening tests that class B 
equipment with high levels of feedback were inferior sonically - and 
methodically went about eliminating or modifying equipment to their taste.

  The cutter heads (stereo) were 3D with Mcintosh 200W amplifiers, with only a 
small amount (10db) of negative feedback from the cutterhead.  The cutterrs were 
flattened using passive custom LC equalizer networks on the inputs of the 
amplifiers.  So it was a very unusual, open loop system.  The Mcintosh amps were 
different from other power amps in that they did not use large amounts of 
inverse feedback around the whole amplifier, and had custom made transformers 
with local feedback windings so they had different characteristics than other 
amps of the day.

I too will stop.

Regards
Gerry Block

________________________________
From: Richard Knoppow <1oldlens1 at ix.netcom.com>
To: Gerry Block <gblock at sbcglobal.net>; Rokumon Cat <rokumoncat at yahoo.com>; 
greenkeys at mailman.qth.net; nagle at animats.com
Sent: Thu, November 29, 2012 9:04:33 AM
Subject: Re: [GreenKeys] Solder

----- Original Message ----- From: "Gerry Block" <gblock at sbcglobal.net>
To: "Rokumon Cat" <rokumoncat at yahoo.com>; <greenkeys at mailman.qth.net>; 
<nagle at animats.com>
Sent: Thursday, November 29, 2012 7:05 AM
Subject: Re: [GreenKeys] Solder

It all started with patchcords. Old fashion recording consoles had patchbays.
There was a real issue with dirt and dielectric issues with the patch cords,
which could add distortion in the audio path because the plug and socket would
be mated poorly. It was easy to hear this phenomenon on low level signals.
Exactly like a dirty wafer switch. Then somebody discovered that they could
hear the difference between patch cords made of different metals. I think it
was Doug Sax, and I have seen the blindfold demonstration. It had more to do
with the cleanliness of the surface. This of course had nothing to do with
solder. But it went from there...

Then it was discovered that capacitors weren't neutral either - this was before
the technique of biasing electrolytic coupling caps in audio circuits (and
before most designers got rid of them).

So like a lot of things there was some truth behind the mysticism and insanity
took over.

The preoccupation with class-A amplifiers (hence the preoccupation with Western
Electric, the purveyor of such things) is real too. Bob Fine was a big
proponent of Class-A amplifiers - in the 1960's. He and his wife did what are
recognized to this day as the finest classical recordings ever made (Mercury
Living Presence). Guess what equipment was used? Western Electric.... In his
studios he removed all the class-B preamplifiers in the recording chain...

Good luck!

Gerry AD6MC

  I generally agree with your comments. I have a theory that the "audiophool" 
phenomenon began with early high-fidelity audio following WW-2. There was a 
period where there were genuine and substantial improvements in recording and 
reproduction but after a time the differences became very slight. There was 
another spate of improvements after the introduction of stereo and when solid 
state appeared.  I think people still want to have something to make them feel 
superior, both by possession of material and what they think is knowledge.  
Audio isn't the only place:-)
  I don't think Bob Fine used much Western Electric stuff in the production of 
the Living Presence series.  While the first really good record cutter for 
lateral recording was the Western Electric 2A, which came with its own 
amplifier, it was followed by several others.  The 2A used feedback from the 
driving coil derived from a secondary voice coil coupled to the driver.  The 
amplifier was especially designed and built for it although the amplifier from 
the older 1A vertical cutter could be used. The control of phase through the 
system was critical.  The main competitor to the 2A was a cutter made by 
Fairchild Instruments. This was a balanced armature cutter but also employed 
feedback and had a dedicated amplifier.  It had better control of response above 
10Khz than the WE cutter did.  Mercury Records also introduced the use of 
variable pitch in cutting, hand done at first, and also was one of the first to 
use a stylus heater. The records were and remain remarkable.  Bob Fine and 
Mercury also used Fairchild tap recorders to make the original recordings.  I 
have heard stories of modifications made to these machines but have no authentic 
information. I never liked the Fairchild design which I think had some tape path 
problems.  One of the major contributors to the quality of the early Mercury 
records was the use of a Telefunken microphone.  While many think this was a 
Neumann mic it was actually made by Schoeps, a model 201-M.  Telefunken was the 
marketing company who distributed many German-made products in the US. Neumann 
made a practice later of removing the Telefunken trade-mark from its microphones 
when they came in for service and replacing it with their own.  A "Telefunken" 
microphone might be a Neumann, or AKG, or Schoeps, and maybe others.
  The Living Presence recordings were mostly made with a single microphone 
rather than the numerous ones used for many other recordings.
    BTW, Fine was supposed to have used McIntosh amps for monitoring.  Back in 
the old days, when I had excellent hearing, I made tests of the better 
amplifiers available and found the McIntosh ones were notably superior to any 
others. While McIntosh began by making a Class-B amp most of them were Class 
AB.  Class-A has the advantage of being affected least by the load so has an 
advantage when used to drive loudspeakers but much of the beliefs about them is 
bunk.
    A final note regarding old solder: there was a discussion on some list I am 
on about solder having an expiration date. In fact, I have rolls of solder with 
such a date.  I think it may have to do with the flux. Its possible the flux 
changes over time and becomes less effective after some period. It would be 
interesting if the Nassau solder is dated and how far out of date it is.

    None of this has anything to do with Teletype so I will shut up now.

--
Richard Knoppow
Los Angeles
WB6KBL
dickburk at ix.netcom.com

NNNN
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