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Re: [ARSCLIST] FW: [ARSCLIST] Internet audio: What do you expect of it ?



The problems are:
1) Cathode emulsion quality (as in, the new tubes don't have it)
2) Cleanliness of the plants (as in, the 2nd world plants aren't very)
3) Inadequate pumping of the tubes because:
a) They don't pump the tubes to sufficient vacuum due to time
b) They can't pump the tubes because the machines are 50 years old
4) The gettering material is impure
5) The metal parts aren't put together with enough care (they are misaligned)


That being said, JJ makes good tubes (though not as good as ANY company from the '50s). SED (aka Winged C) also makes good tubes. The Chinese tubes aren't as putrid as they once were, but they still suck compared to any decent tube from the '60s to early '70s.

There are plenty of dumpster tubes that can be used in new designs that could keep tube audio going for a long time. TV tubes, weird filament voltages, etc.. Some of the makers are making decent enough tubes that they can be aged, tested out and the worst ones rejected. Several outfits age the tubes, test them at real life voltages and do real matching. I made the mistake of buying a, /ahem/, "matched quad" of Svetlana EL34. What a joke. One tube had an intermittent short, one was gassy and the other two were "just okay". I got these at a guitar center. I took them back, got another new set and had the same problems. I don't like badmouthing companies, but avoid Svetlana for any serious application, UNLESS you are buying them from someone you trust that has aged and tested them under real world conditions. The same thing applies to the Chinese tubes. JJ and SED are worth trusting. They try. Unfortunately, if they really built tubes to the same quality as tubes made in the '60s, they'd have to rebuild all their machinery, improve all their materials several times over and charge 10X the price. Then, all the guys who are so romantic about tubes would get romantic about transistors. Just consider what the price was for a tube in 1950, look at the price today, and calculate for inflation. We're paying way less for tubes when you consider inflation (just like for CDs).
Phillip Holmes


Scott Phillips wrote:
..you might change your mind, when the NOS tubes run out and all you can
get are the terrible quality tubes from the eastern bloc countries. It
is getting painful and very expensive to find good sounding tubes even
for guitar amplifiers. I sometimes have to service tube equipment, and
the characteristics of new tubes vary all over the map. Cathode and grid
bias settings in the amplifiers don't hold at all any more because the
newly manufactured tubes are so poor. New-old-stock tubes from the US
and Europe were very stable from tube to tube. There just isn't anyplace
that wants to pollute the environment making them anymore, except where
they don't care about that. Must be why they don't care about the tube
quality either....

-----Original Message-----
From: Association for Recorded Sound Discussion List
[mailto:ARSCLIST@xxxxxxx] On Behalf Of Roger and Allison Kulp
Sent: Friday, December 21, 2007 4:29 PM
To: ARSCLIST@xxxxxxxxxxxxxxxx
Subject: Re: [ARSCLIST] FW: [ARSCLIST] Internet audio: What do you
expect of it ?

When I listen to anything other than a computer,I refuse to use anything
but tubes.


Roger


Robert J Hodge <rjhodge@xxxxxxx> wrote: -----Original Message-----
From: Robert J Hodge
Sent: Wednesday, December 19, 2007 9:25 AM
To: 'jhartke@xxxxxxxxxxxx'
Subject: RE: [ARSCLIST] Internet audio: What do you expect of it ?

When the transistor was first marketed as an amplifying device, it
suffered from its' ability to act like a switch- that is to say until
the signal at the base became high enough to make it conduct. Germanium
and early silicon based transistors had this anomalism.
I had a couple of those early amplifiers and got rid of them after
trying to live with them. At low signal levels, they sounded terrible.

As with anything of an early design, this problem was overcome with
better transistor design.

I have used mosfet power amplifiers now for many years and will never go
back to the tube units. Of course, even overdriving a mosfet unit will
sound terrible! Clipped is clipped.

I keep the tube units around, just in case.

Bob Hodge
-----Original Message-----
From: Association for Recorded Sound Discussion List
[mailto:ARSCLIST@xxxxxxx] On Behalf Of Jerry Hartke
Sent: Wednesday, December 19, 2007 6:40 AM
To: ARSCLIST@xxxxxxxxxxxx
Subject: Re: [ARSCLIST] Internet audio: What do you expect of it ?


Being rather ancient, I go back to tube amplifiers of the 1940's, and am
confused about the reference to "solid state distortion." Does this
refer to hard clipping when transistors are overdriven? Although tube
amplifiers clip more gradually, they also introduce distortion in the
process. Thus neither form of amplification should be overdriven.

Tube amplifiers are limited by their output transformer that matches the
high output impedance of the tubes to a low load impedance. This
transformer significantly degrades frequency and phase response, placing
severe constraints on the amount of negative feedback that reduces the
inherent distortion of the amplifier. I paid as much as $100 back in the
'50s for a superior output transformer, and still struggled to achieve
20-20,000 Hz with 0.1% intermod.

Solid state amplifiers normally do not have output transformers, and
thus can use greater amounts of negative feedback. This results in much
lower distortion, better frequency (and transient) response, and
superior damping than that achieved by most tube amplifiers. It seems
that solid state amplification would be preferable provided that
amplitudes stayed within their dynamic range (always necessary for
fidelity.)

I do not disagree with those, including myself, raised on tube
amplifiers and accustomed to their limited frequency response and
somewhat higher distortion. Many of us like this "sound." However, we
should not confuse this preference with faithful reproduction.

Jerry Hartke

-----Original Message-----
From: Association for Recorded Sound Discussion List [mailto:ARSCLIST@xxxxxxx] On Behalf Of Steven C. Barr(x)
Sent: Tuesday, December 18, 2007 11:06 PM
To: ARSCLIST@xxxxxxxxxxxxxxxx
Subject: Re: [ARSCLIST] Internet audio: What do you expect of it ?


----- Original Message -----
From: "Don Cox"
Hello Steven
On 18/12/07, Steven C. Barr(x) wrote:
----- Original Message -----
From: "Roger and Allison Kulp"
I see it as a latter day version of the all-tube FM tuner,rather
than
the CD/phono amp.

Keep in mind that the appeal of vacuum-tube audio equipment is NOT
its
"perfect" reproduction (which probably doesn't...in fact,
CAN'T...exist?!) but rather the fact that the distortion it
generates
is much more enjoyable for steady listening than its solid-state equivalent...?!
Yes, but if you feed an unpleasantly distorted signal into a box
with a
tube in it, the tube will not magically remove that unpleasantness.

Remarkable things can be done with software to improve a nasty recording, and I expect such software to improve in the future, but
a
simple tube based amplifier stage cannot make a silk purse out of a sow's ear.

That, actually, was my point...! If an audio signal has been, at any point in its life, been subjected to solid-state distortion...

1) The listener has my deepest sympathy...

2) AND...the signal will never again sound good, regardless of what it

is played on/through...!

Steven C. Barr


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