There is nothing a tube amp can do that a SS version cant emulate with the
proper circuit.
OTOH comparing a plain vanilla version of both and there is a very noticable
difference.
Some of the best AM signals on the bands are SS amps used as drivers or in
some cases as the modulators with the necessary transformer changes. Class E
and SDR rigs sound absolutely great but Im not ready to go to the dark side
yet....
Broadcasters forgot how to generate quality audio decades ago. All the crap
they hang on for processing will destroy the sound of even the best tube TX.
Very few receivers, SS and especially tube can handle much over 100%
positive modulation with out moderate to extreme distortion.
If you hang a sectrum analyzer (fancy panadaptor) on a receiver you can see
what sort of crap goes out from many BCB and ham stations. What may sound
impressive on frequency is sending strange artifacts up and down the band.
Now the BC crowd want the FCC to allow modified controlled carrier so they
can save money on their electric bill.
Carl
KM1H
----- Original Message -----
From: "Paul Christensen" <w9ac@arrl.net>
To: "Ed" <elh54@sbcglobal.net>; <Amps@contesting.com>
Sent: Monday, April 16, 2012 10:18 AM
Subject: Re: [Amps] NAB...hope from the old world for the new?
>I believe the speaker for that session was Bill Whitaker, a well-respected
> engineer. Probably Jim, K9YC knows him on a first-name basis.
>
> The vacuum tube v. solid-state debate has been raging on since the
> invention
> of the transistor. Much of the vacuum tube hype among audiophiles during
> the past decade has been based on non-quantifiable audio attributes.
> Because so much of what we hear is arbitrary, and not measured, it has
> opened up an entire cottage industry of super-high-priced audio
> amplifiers,
> pre-amps, cabling, and accessories.
>
> I have yet to hear a VT amp that cannot compete with a well-designed
> solid-state amp when good design decisions are paid to source Z/damping
> factor, power supply design, and especially negative feedback over the
> 20Hz
> to 20 kHz response curve. In my opinion, the latter is the most deficient
> design attribute today, mostly ignored by some of the world's leading
> audio
> engineers. The link below discusses this effect in detail.
>
> http://sound.westhost.com/highspeed.htm
>
> Last spring, I replaced the audio output stage in my Drake R-4B receiver.
> The R-4B's cabinet runs incredibly hot, primarily due to an inefficient
> class-A design. Despite being class-A, distortion is relatively high
> (owing
> to the design of the output transformer -- a mass-produced type used in
> ca.
> 1965 TV sets) as is residual hum when using high-performance headphones.
> In
> its place is now a 4-watt solid-state amp, designed by SM0VPO. It is an
> ultra-low noise class-B PP, with much attention paid to the negative
> feedback loop. I won't get into all the descriptive adjectives to compare
> sonic quality between the old and new amp. What I care about are the
> measurements. If it cannot be measured, I don't think it's an issue worth
> discussing. If it's being hyped and not measured, then time is not taken
> to
> conduct the measurement. And, so many attributes of amplifiers described
> in
> the media focus only on warm and fuzzy feelings, and not measurements.
> There's not one attribute that cannot be measured.
>
> Some design deficiencies of VT amps have become a positive thing. Look at
> the hype concerning how good even harmonic distortion sounds. I suppose
> it
> does, depending on the application. How about how good odd-order products
> sound - the stuff we all seem to try and eliminate? A metal guitar
> plugged
> into a deliberately over-driven Marshall amp produces much odd harmonic
> content depending on how its biased and driven. That same guitar plugged
> into a 100% linear amp sounds a lot different and its not a sound most
> musicians want. But that is something that can also be measured and
> incorporated into a solid-state amp. Even so-called "soft clipping of
> tubes" can be easily emulated in a SS amp with little effort.
>
> So, I'm not sure why this topic was presented at the NAB convention. I
> can't think of anything radically new in audio VT technology that hasn't
> been discussed at an NAB convention say...sixty years ago.
>
> Paul, W9AC
>
>
> ----- Original Message -----
> From: "Ed" <elh54@sbcglobal.net>
> To: <Amps@contesting.com>
> Sent: Monday, April 16, 2012 9:19 AM
> Subject: [Amps] NAB...hope from the old world for the new?
>
>
>> My friend just returned from NAB this morning, I thought I would share
>> this line from his email with all of you:
>> I attended a session Saturday at NAB - about VACUUM TUBES. They billed it
>> as the first session at NAB about tubes in 30 years. It concentrated on
>> the sound from tube-type audio gear (is it better or just different??).
>> Thought about you.
>>
>> -Cecil
>> 73,
>> kv5i
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>
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