[TowerTalk] RE: TowerTalk Digest, Vol 23, Issue 62

Dudley Chapman chief at thechief.com
Wed Nov 17 15:00:41 EST 2004


There is definitely a subjective difference between solid state and tube
type audio amplifiers.  But as many have indicated here, it is the artifacts
that the tube type amplifiers provide that make it more pleasing to some
people.  Surely the early SS designs had a lot of THD, but these days with
distortion into the many decimal points, its hard to imagine that modern SS
amplifiers have an unpleasing distortion. 

Some of the preference for tube amps is learned, in that us old timers grew
up with hiss from the front end, and low end phase shift in the interstage
and output transformers.  We learned to like this kind of sound along with
the sweet distortion from the soft-clipping that tubes offer, accentuating
the even harmonics.  The same thing seems to happen with hiss.  In a blind
test, if you have people listen to very clean sound system, they claim it
has better highs when you inject some white noise, vs when you don't.  It's
a learned response where we have associated high freq response with the
presence of hiss.

I wonder if you would get different results if you did a comparison of high
quality tube and SS amps with older people vs the same test with young
people?  You would need to find young people who didn't grow up thinking the
audio from a Seeburg jukebox was good audio.

By the way, I too remember load lines, the RCA Tube Manual, and Hickock Tube
testers.  That darned paper roll with all the switch settings for each tube
was always out of date, it seemed.  My first transmitter was a 6AV6 on the
AM BC band built on a cigar box.  Hey, I think we need a OF (sorry, OT) list
so we can reminisce.

So as to legitimize my posting on TT, I should ask a question I have been
meaning to put forth here.  What is the best way to connect a 2 inch wide
ground strap (solid copper flashing) between the single point ground amateur
"service box" and the electrical service?  The amateur ground box is a nema
enclosure located 2 feet from the electrical meter box and grounded to a
perimeter ground.  I could strap from box to box, or I could run the strap
from the amateur box right into the house to the inside electric service
panel for a run of about 4 feet of strap. 

Dudley - WA1X

Message: 4
Date: Wed, 17 Nov 2004 08:55:37 -0500
From: "Tom Rauch" <w8ji at contesting.com>
Subject: [TowerTalk] Tube vs Transistor
To: <towertalk at contesting.com>
Message-ID: <019f01c4ccad$1e489be0$6501a8c0 at akorn.net>
Content-Type: text/plain;	charset="iso-8859-1"

We took a "high end" tube stereo with low distortion and a fair quality
solid state stereo and did a blind test with a few people who claimed they
could hear the difference.

There wasn't the slightest indication anyone could tell any difference. The
minute we added distortion they called it "better"!

I worked on a small tube type amplifier "designed" by a tube lover, and it
had horrible distortion caused by improper resistor selection. It was very
easy to see the distortion on a scope, let alone measure it with distortion
meters.

When I corrected the bias and load resistor values, a tube audio guru had an
absolute fit. He claimed I "ruined" the fidelity and "warmth" of the
amplifier. Restoring resistor values so the tubes produced non-symmetrical
waveforms brought the "warmth" back into the sound.

Some people like distorted or non-linear audio.  Nothing wrong with that.
Let's just not paint it as being "cleaner".

73 Tom


Dudley Chapman
Native Logic Inc.
Tel: 330.715.0767
Fax: 509.275.6316
Dudley.Chapman at native-logic.com
http://www.native-logic.com
AIM: Chiefley
-----Original Message-----
From: towertalk-bounces at contesting.com
[mailto:towertalk-bounces at contesting.com] On Behalf Of
towertalk-request at contesting.com
Sent: Wednesday, November 17, 2004 11:02 AM
To: towertalk at contesting.com
Subject: TowerTalk Digest, Vol 23, Issue 62

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Today's Topics:

   1. RE: Vacuum tube 100 years old today (Al N6TA)
   2. Re: 80m 4Square Dipole VSWR question (Tom Rauch)
   3. Re: Vacuum tube 100 years old today (Bill VanAlstyne, W5WVO)
   4. Tube vs Transistor (Tom Rauch)
   5. RE: Tube vs Transistor (Keith Dutson)
   6. 8X center migration in a coax choke? (Rob Atkinson, K5UJ)
   7. dump power? (Al Williams)


----------------------------------------------------------------------

Message: 1
Date: Tue, 16 Nov 2004 20:41:33 -0800
From: "Al N6TA" <n6ta at arrl.net>
Subject: RE: [TowerTalk] Vacuum tube 100 years old today
To: "Gene Smar" <ersmar at comcast.net>,	"Jim Miller"
	<JimMiller at STL-Online.Net>, <towertalk at contesting.com>
Message-ID: <JDEBIOMFHBBIFICDDEKDAEFLCMAA.n6ta at arrl.net>
Content-Type: text/plain;	charset="iso-8859-1"

I work for a guy who makes serious efforts trying to get the 'truest' audio.
He talks of the 'infetesimal perceptible' that needs to be considered when
evaluating the quality of an audio recording and its reproduction to sound
waves.  His CD player is a hybrid tube and solid state unit that costs over
$5,000.  Imagine the rest of the components in the chain...

-----Original Message-----
From: towertalk-bounces at contesting.com
[mailto:towertalk-bounces at contesting.com]On Behalf Of Gene Smar
Sent: Tuesday, November 16, 2004 13:32
To: Jim Miller; towertalk at contesting.com
Subject: Re: [TowerTalk] Vacuum tube 100 years old today

TT:

     There was an interesting (to me) article in the August 1998 issue of
IEEE Spectrum magazine about the continued use of vacuum tubes in high-end
audio equipment and musical instrument amplifiers.  The article's main
thesis is that tubes provide "better-sounding" audio at high levels than
could (or still can) be achieved by solid-state audio processing circuitry.
Apparently there are still some applications besides QRO microwaves for
which such hollow-state devices are better suited.

73 de
Gene Smar  AD3F

----- Original Message -----
From: "Jim Miller" <JimMiller at STL-Online.Net>
To: <towertalk at contesting.com>
Sent: Tuesday, November 16, 2004 4:16 PM
Subject: Re: [TowerTalk] Vacuum tube 100 years old today


> I was in missile class in the Air Force in 1963 and the lab and course was
> entirely in tubes even though the missile was entirely in transistors.
The
> adaptation was very short (minutes, maybe and hour) and said that
> transistors worked like tubes except at lower voltages and power levels.
> That was all there was to transistors !!!  Not bad really for a class that
> hadn't been rewritten yet (and that may have been all the instructor knew
at
> that time).
>
> 73, de Jim KG0KP
>
> ----- Original Message -----
> From: "Bob Nielsen" <nielsen at oz.net>
> To: <towertalk at contesting.com>
> Sent: Tuesday, November 16, 2004 12:10 PM
> Subject: Re: [TowerTalk] Vacuum tube 100 years old today
>
>
> > On Tue, Nov 16, 2004 at 11:28:11AM -0500, Tom Rauch wrote:
> > > On Nov. 16, 1904 Fleming patented the Fleming valve. The
> > > vacuum tube is 100 years old today (exactly 46 years to the
> > > day older than I am).
> > >
> > > I was an electrical engineering student in the late 60's.
> > > The electronics lab stock room was full of tubes and
> > > sockets, and our benches had 300 volt power supplies. About
> > > 50% of our inventory and study was tube related. I built a
> > > complete 500 watt HF station, receiver and transmitter, from
> > > stock room parts in my spare time. Every component necessary
> > > was in the stock room. From a textbook I still use,
> > > "Electronic Amplifier Circuits" McGraw-Hill Electrical
> > > Engineering Series 1961, comes the following quote:
> > >
> > > "For many applications a relative newcomer, the transistor,
> > > is replacing vacuum tube types because of the greater
> > > inherent reliability, lower power consumption, and smaller
> > > size. However, the complete replacement of the tube by the
> > > transistor does not seem likely, for the latter has
> > > shortcomings at high temperatures and high radiation
> > > intensities and in the production of high power at high
> > > frequencies. "
> > >
> > > About ten years later I received a call asking if I wanted
> > > any of those old tubes, tube related books, or HV bench
> > > power supplies before they hit the dumpster.
> > >
> >
> > I was taking a senior physics class in electronics at UCLA in 1962 and
> > we spent some time studying vacuum tube circuits.  The professor was
> > asked if we were going to learn anything about transistors and replied
> > that he had never studied them himself, since he felt that they were a
> > fad which wouldn't last.
> >
> > 73,
> > Bob N7XY
> > _______________________________________________
> >
> > See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless
> Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with
any
> questions and ask for Sherman, W2FLA.
> >
> > _______________________________________________
> > TowerTalk mailing list
> > TowerTalk at contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
> >
>
>
> _______________________________________________
>
> See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk

_______________________________________________

See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.

_______________________________________________
TowerTalk mailing list
TowerTalk at contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk



------------------------------

Message: 2
Date: Wed, 17 Nov 2004 05:31:24 -0500
From: "Tom Rauch" <w8ji at contesting.com>
Subject: Re: [TowerTalk] 80m 4Square Dipole VSWR question
To: "D. Rodman, MD" <rodman at buffalo.edu>,	"towertalk"
	<towertalk at contesting.com>
Cc: topband at contesting.com
Message-ID: <015501c4cc90$96d4c560$6501a8c0 at akorn.net>
Content-Type: text/plain;	charset="iso-8859-1"

> The NE/SW pair have resonance curve at 3.58 and 3.57 MHz
using an Autek
> meter.  The NW/SW pair are resonant at 3.66 and 3.67 MHz.
VSWR with the
> transceiver show identical measurements with and without
amplifier.  I had
> questioned possible interaction between the tower, nearby
antennas with
> the 4Square so I wanted to use a low power device to
measure the VSWR
> curves.

The power of the device has nothing at all to do with the
SWR and mutual coupling.


You must have other antennas or objects around interfering
with the dipoles. The only way to know what effect it has is
to watch the pattern. Dump power tells you almost nothing
except what the dump power is. It does not indicate anything
but impedance presented by the load and power wasted because
you are using a mismatched hybrid. Zero dump power does not
mean the elements have the correct current or phase, and
high dump power does not mean the pattern is bad.

73 Tom




------------------------------

Message: 3
Date: Wed, 17 Nov 2004 06:39:34 -0700
From: "Bill VanAlstyne, W5WVO" <w5wvo at cybermesa.net>
Subject: Re: [TowerTalk] Vacuum tube 100 years old today
To: <towertalk at contesting.com>
Message-ID: <003001c4ccaa$e12a5110$0400a8c0 at billscomputer>
Content-Type: text/plain;	charset="iso-8859-1"

This is all off-topic, of course, but so fascinating... Hopefully we'll all
be
forgiven.  :-)  I once had the opportunity, at an audiophile friend's home,
to
do a blindfolded side-by-side comparison of two audio amplifiers he was
testing,
one a recent solid-state design that was very well-regarded in the
audiophile
community, the other a hollow-state rig, also brand new and equally
well-regarded, producing approximately the same amount of power. Everything
else
in the test was identical -- music (on virgin vinyl, of course), turntable,
preamp (tube, of course), and speakers.

And yes, I could hear the difference. The tube amplifier was better. It was
very
subtle, but clearly identifiable: The solid-state amplifier produced a
beautiful, clear, warm, 2-D separation of the musicians on the "sound
stage",
but the tube amplifier went one step better and produced a sense of 3-D
depth
that I could actually hear. The drummer, for example, instead of being
located
"there", could be heard to be located "there, and back about ten feet". I
didn't
know which amplifier was producing which test until afterwards.

Is this a function of overtones, or harmonics, or what? I don't think
anybody
really knows. But don't scoff at those who say they can hear a difference
this
subtle. Been there, done that.  :-)

Bill / W5WVO


Al N6TA wrote:
> I work for a guy who makes serious efforts trying to get the 'truest'
> audio.
> He talks of the 'infetesimal perceptible' that needs to be considered
> when
> evaluating the quality of an audio recording and its reproduction to
> sound
> waves.  His CD player is a hybrid tube and solid state unit that
> costs over $5,000.  Imagine the rest of the components in the chain...
>
> -----Original Message-----
> From: towertalk-bounces at contesting.com
> [mailto:towertalk-bounces at contesting.com]On Behalf Of Gene Smar
> Sent: Tuesday, November 16, 2004 13:32
> To: Jim Miller; towertalk at contesting.com
> Subject: Re: [TowerTalk] Vacuum tube 100 years old today
>
> TT:
>
>      There was an interesting (to me) article in the August 1998
> issue of
> IEEE Spectrum magazine about the continued use of vacuum tubes in
> high-end
> audio equipment and musical instrument amplifiers.  The article's main
> thesis is that tubes provide "better-sounding" audio at high levels
> than
> could (or still can) be achieved by solid-state audio processing
> circuitry.
> Apparently there are still some applications besides QRO microwaves
> for
> which such hollow-state devices are better suited.
>
> 73 de
> Gene Smar  AD3F
>
> ----- Original Message -----
> From: "Jim Miller" <JimMiller at STL-Online.Net>
> To: <towertalk at contesting.com>
> Sent: Tuesday, November 16, 2004 4:16 PM
> Subject: Re: [TowerTalk] Vacuum tube 100 years old today
>
>
>> I was in missile class in the Air Force in 1963 and the lab and
>> course was entirely in tubes even though the missile was entirely in
>> transistors.
> The
>> adaptation was very short (minutes, maybe and hour) and said that
>> transistors worked like tubes except at lower voltages and power
>> levels. That was all there was to transistors !!!  Not bad really
>> for a class that hadn't been rewritten yet (and that may have been
>> all the instructor knew
> at
>> that time).
>>
>> 73, de Jim KG0KP
>>
>> ----- Original Message -----
>> From: "Bob Nielsen" <nielsen at oz.net>
>> To: <towertalk at contesting.com>
>> Sent: Tuesday, November 16, 2004 12:10 PM
>> Subject: Re: [TowerTalk] Vacuum tube 100 years old today
>>
>>
>>> On Tue, Nov 16, 2004 at 11:28:11AM -0500, Tom Rauch wrote:
>>>> On Nov. 16, 1904 Fleming patented the Fleming valve. The
>>>> vacuum tube is 100 years old today (exactly 46 years to the
>>>> day older than I am).
>>>>
>>>> I was an electrical engineering student in the late 60's.
>>>> The electronics lab stock room was full of tubes and
>>>> sockets, and our benches had 300 volt power supplies. About
>>>> 50% of our inventory and study was tube related. I built a
>>>> complete 500 watt HF station, receiver and transmitter, from
>>>> stock room parts in my spare time. Every component necessary
>>>> was in the stock room. From a textbook I still use,
>>>> "Electronic Amplifier Circuits" McGraw-Hill Electrical
>>>> Engineering Series 1961, comes the following quote:
>>>>
>>>> "For many applications a relative newcomer, the transistor,
>>>> is replacing vacuum tube types because of the greater
>>>> inherent reliability, lower power consumption, and smaller
>>>> size. However, the complete replacement of the tube by the
>>>> transistor does not seem likely, for the latter has
>>>> shortcomings at high temperatures and high radiation
>>>> intensities and in the production of high power at high
>>>> frequencies. "
>>>>
>>>> About ten years later I received a call asking if I wanted
>>>> any of those old tubes, tube related books, or HV bench
>>>> power supplies before they hit the dumpster.
>>>>
>>>
>>> I was taking a senior physics class in electronics at UCLA in 1962
>>> and we spent some time studying vacuum tube circuits.  The
>>> professor was asked if we were going to learn anything about
>>> transistors and replied that he had never studied them himself,
>>> since he felt that they were a fad which wouldn't last.
>>>
>>> 73,
>>> Bob N7XY
>>> _______________________________________________
>>>
>>> See: http://www.mscomputer.com  for "Self Supporting Towers",
>>> "Wireless
>> Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041
>> with
> any
>> questions and ask for Sherman, W2FLA.
>>>
>>> _______________________________________________
>>> TowerTalk mailing list
>>> TowerTalk at contesting.com
>>> http://lists.contesting.com/mailman/listinfo/towertalk
>>>
>>
>>
>> _______________________________________________
>>
>> See: http://www.mscomputer.com  for "Self Supporting Towers",
>> "Wireless
> Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041
> with any
> questions and ask for Sherman, W2FLA.
>>
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk at contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
>
> _______________________________________________
>
> See: http://www.mscomputer.com  for "Self Supporting Towers",
> "Wireless
> Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041
> with any
> questions and ask for Sherman, W2FLA.
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
> _______________________________________________
>
> See: http://www.mscomputer.com  for "Self Supporting Towers",
> "Wireless Weather Stations", and lot's more.  Call Toll Free,
> 1-800-333-9041 with any questions and ask for Sherman, W2FLA.
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk



------------------------------

Message: 4
Date: Wed, 17 Nov 2004 08:55:37 -0500
From: "Tom Rauch" <w8ji at contesting.com>
Subject: [TowerTalk] Tube vs Transistor
To: <towertalk at contesting.com>
Message-ID: <019f01c4ccad$1e489be0$6501a8c0 at akorn.net>
Content-Type: text/plain;	charset="iso-8859-1"

We took a "high end" tube stereo with low distortion and a
fair quality solid state stereo and did a blind test with a
few people who claimed they could hear the difference.

There wasn't the slightest indication anyone could tell any
difference. The minute we added distortion they called it
"better"!

I worked on a small tube type amplifier "designed" by a tube
lover, and it had horrible distortion caused by improper
resistor selection. It was very easy to see the distortion
on a scope, let alone measure it with distortion meters.

When I corrected the bias and load resistor values, a tube
audio guru had an absolute fit. He claimed I "ruined" the
fidelity and "warmth" of the amplifier. Restoring resistor
values so the tubes produced non-symmetrical waveforms
brought the "warmth" back into the sound.

Some people like distorted or non-linear audio.  Nothing
wrong with that. Let's just not paint it as being "cleaner".

73 Tom




------------------------------

Message: 5
Date: Wed, 17 Nov 2004 09:48:53 -0600
From: "Keith Dutson" <kjdutson at earthlink.net>
Subject: RE: [TowerTalk] Tube vs Transistor
To: "TowerTalk" <towertalk at contesting.com>
Message-ID: <E1CUS30-0005z6-00 at pop-a065d23.pas.sa.earthlink.net>
Content-Type: text/plain;	charset="us-ascii"

Agree with this assessment.  I use a McIntosh MA6100 amp/preamp and
Sennheiser headphones (to eliminate spousal complaints about loud music) at
home.  This amp is not offered now, going out of production many years ago.
It was the first all solid state and first amp/preamp offered by the
company.  THD is less than .01% at 70 watts per channel RMS into 8 ohms,
20Hz to 20KHz (as shown on chart produced by spectrum analyzer).  It sounds
as good or better than any tube equipment I have ever heard, with speakers
or headphones.  The setup is about as clean as you can get.  BTW, the MA6100
is very heavy, primarily due to use of massive auto transformers at the
speaker terminals which yield a damping factor 50.

Keith NM5G

-----Original Message-----
From: towertalk-bounces at contesting.com
[mailto:towertalk-bounces at contesting.com] On Behalf Of Tom Rauch
Sent: Wednesday, November 17, 2004 7:56 AM
To: towertalk at contesting.com
Subject: [TowerTalk] Tube vs Transistor

We took a "high end" tube stereo with low distortion and a fair quality
solid state stereo and did a blind test with a few people who claimed they
could hear the difference.

There wasn't the slightest indication anyone could tell any difference. The
minute we added distortion they called it "better"!

I worked on a small tube type amplifier "designed" by a tube lover, and it
had horrible distortion caused by improper resistor selection. It was very
easy to see the distortion on a scope, let alone measure it with distortion
meters.

When I corrected the bias and load resistor values, a tube audio guru had an
absolute fit. He claimed I "ruined" the fidelity and "warmth" of the
amplifier. Restoring resistor values so the tubes produced non-symmetrical
waveforms brought the "warmth" back into the sound.

Some people like distorted or non-linear audio.  Nothing wrong with that.
Let's just not paint it as being "cleaner".

73 Tom


_______________________________________________

See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.

_______________________________________________
TowerTalk mailing list
TowerTalk at contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk



------------------------------

Message: 6
Date: Wed, 17 Nov 2004 15:49:11 +0000
From: "Rob Atkinson, K5UJ" <k5uj at hotmail.com>
Subject: [TowerTalk] 8X center migration in a coax choke?
To: towertalk at contesting.com
Message-ID: <BAY101-F350dSHpVyLr00022bf1 at hotmail.com>
Content-Type: text/plain; format=flowed

tnx Tom for ur very complete and valuable advice.  I am dissatisfied with 
the performance of my ferriet on 160, as it is probably geared more for HF.

It is a good time to give coax chokes a try.  I think I can proceed with 
some confidence now.

73

rob/k5uj

_________________________________________________________________
FREE pop-up blocking with the new MSN Toolbar  get it now! 
http://toolbar.msn.click-url.com/go/onm00200415ave/direct/01/



------------------------------

Message: 7
Date: Wed, 17 Nov 2004 08:02:03 -0800
From: "Al Williams" <alwilliams at olywa.net>
Subject: [TowerTalk] dump power?
To: "towertalk" <towertalk at contesting.com>
Message-ID: <001301c4ccbe$cdf11d40$25daadd8 at olywa>
Content-Type: text/plain;	charset="Windows-1252"

I did a google search on "dump power" and got 149 hits including two of
Tom's towertalk posting.
Other hits ranged from John Deere's tractors to garbage dumps but at
least two others indicated that it is a common term used in power lines
and also integrated circuit power line layout.

I suspect that some other Towertalkians are like me and it is an
unfamiliar term.  We will appreciate an explanation?

k7puc



------------------------------

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End of TowerTalk Digest, Vol 23, Issue 62
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