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

[Scott Phillips <scottp@xxxxxxxxxxxxxxxxxxx>]

A lot of the early transistor designs were attempts to use basic tube
circuit principles with transistors. Regular bipolar transistors aren't
all that linear all by themselves, they required new ways of thinking.
Until that happened, solid state amps sounded horrid. When MOSFET
transistors and designs came along and got sorted out, it changed again.
FET and MOSFET transistors have basic characteristics much more like a
tube then the older bipolar transistors.
	Granted any modern amplifier can sound nasty if clipped, tube or
transistor based. Tubes do have a tendency so loved by some of going
into a form of compression before they hard clip, and have a different
character to the distortion produced then. Even if the tubes themselves
were perfectly linear, the output transformers certainly are not. At the
least, a typical tube amp may spend more of its time in some form of
distortion... Tube amps of very high power are hard to make and very
expensive, while a 1000 watt MOSFET amp is close to $1 a watt. A tube
amp might be much more than $10 a watt. For $1000, which one do you
think you will drive to clipping more often? If the 'punchy' sound of
the amplifier acting as a compressor is your thing, try a real
compressor instead.
	Replacement JBL speaker drivers used to come with a label in the
box saying "Danger: Low Power !" in them, with a detailed warning about
the dangers of using too LOW a powered amplifier with them. An amp in
clipping generates waveforms that a speaker driver can't possibly
follow, so they tear themselves apart trying. 
	My professional experience has been that speakers had a longer
life and sounded better when the amplifier used had a rating at least
several times the rated maximum power for the speakers. Speakers handle
sudden short duration peak powers very, very well. It is clipped or long
duration excess level that will kill them. The rule of thumb still
applies regardless... If it is loud and sounds gritty, sloppy, or bad,
turn the durn thing down until it doesn't !

	Having higher power available is just much more practical with
solid state amps, and just because they once sounded lousy doesn't mean
they still do. By the way, I love tubes and some of the sonics they
make.... I just don't confuse the way they color the sound with better
fidelity.... Just different. More pleasing to some, less accurate to
others. For personal use, which ever you like. For professional use:
Use professional, well designed solid state amplifiers.

...Just my view, your mileage my vary.... :>)

Scott

-----Original Message-----
From: Association for Recorded Sound Discussion List
[mailto:ARSCLIST@xxxxxxx] On Behalf Of Robert J Hodge
Sent: Wednesday, December 19, 2007 9:39 AM
To: ARSCLIST@xxxxxxxxxxxxxxxx
Subject: [ARSCLIST] FW: [ARSCLIST] Internet audio: What do you expect of
it ?

-----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" <doncox@xxxxxxxxxxxxxx>
> > Hello Steven
> > On 18/12/07, Steven C. Barr(x) wrote:
> > > ----- Original Message -----
> > > From: "Roger and Allison Kulp" <thorenstd124@xxxxxxxxx>
> > >> 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