There's all sorts of mythology and BS about home hifi (presumably) amplification. The big
misinformation is broadcast by dubious claims of manufacturers peddling super-priced stuff to the
audiophool crowd, and the accompanying mags.
The goal of a home audio amp should be NEUTRALITY. It should take source material, from preamps or
direct from sources like tuners, CD players and phono preamps, and amplify it by several orders of
magnitude so as to drive mechanical devices (speakers) to move air and thus produce sound waves. The
speakers themselves are actually the biggest sound-alterers in most systems, interacting with the
room and themselves to produce all sorts of effects. Some go to great lengths to minimize these
various distortions and effects, some choose closer-in monitoring, some listen on headphones, some
find a very pleasing match of room acoustics and a favorite pair of speakers.
Now, when you get into the amplifier itself, I don't think some sort of frothy "tubes vs.
transistors" argument is even worth addressing. What is worth addressing is what sorts of
distortions and sound-alterations are likely under what circumstances. Most but not all tube amps
are of lesser watts into a given ohms of power than comparably-priced/built solid-state amps. Most
but not all tube amps use an output transformer between the output stage and the speaker. The
transformers can and do produce distortions, and peak-overdriving the tubes can and do produce
distortions. Tube distortion is generally in "musical" harmonics and can sometimes manifest as a
"warm" fuzz around an instrument's fundamental sound. Some people find this very desireable, indeed
many electric guitarists I know love it and force their amps into overdrive -- sometimes different
overdrive levels in the first stage vs. the output stage and other stages in-between -- and most
"classic" electric guitar riffs and songs are fraught with what is mostly classic tube overdrive
distortion (and also "barking" speakers and overloaded output transformers, and some even like and
seek out power supply sagging). In the home hifi environment, I would submit that accuracy is
preferable but there are guys much richer than me proving me wrong with amps designed to produce
that "warm" fuzz for other guys richer than me willing to shell out mega-bucks to hear it.
With solid-state amps, first of all, an early bad reputation developed from early bad designs. By
the "golden age" of hifi, tube amps had undergone steady improvement and development since the
1920's, ie about 30 years. Solid-state gear in the mid-60's was fraught with bad designs (trying to
copy tube topology for active devices that did not behave like tubes, for example), infant
technology (noise-prone and thermal-problem-prone transistors, for example), and over-marketing
(looking back on early solid-state advertising, there were some pretty hefty claims made for pretty
feeble equipment). As with tubes, things improved with time and I would submit that there are many
superb examples of solid-state amps on the market now and have been many good choices for the past
20 years or more. The devices improved, new and better circuits were discovered and since
transistors are cheap and transistor overload distortion is just plain ugly to most ears, output
power overkill has been the norm (basic philosophy -- make it have such available peak power as to
never show the ugly clipping side of transistor power/distortion curves). Things like rise-time and
transient distortions were addressed with more modern designs and solid-state devices. Also,
reputable modern amps have good fail-safe circuits to prevent burning up speakers when a device
blows up. The latest wrinkle is Class D amps, but I've never tried them and don't fully understand
them so I don't want to comment.
In my systems, I have tube amps and transistor amps and I like them all. My goal in each setup is to
provide enough available power so as not to get into distortions, and to provide maximum accuracy.
The curse of this approach is that many recordings sound pretty darn bad when cast under an accurate
light but the blessing is to hear true professionalism at work with no filtering or hype in the case
of those rare recordings that just leap out of the speakers and take you to a place and time. I
would argue that in a studio environment, accuracy is paramount because you can't do your job
correctly if you can't correctly hear the good and bad and know what you have to do when remedies
Finally circling around to Steve's question about dynamic range -- no, tube amps are not inherently
able to produce greater dynamic range, but most folks notice when a solid-state amp is underpowered
a lot quicker than with a tube amp because transistor clipping/overload sounds universally horrible
except perhaps to people who love the harshest sounds produceable on an early Moog. By the way, most
factory car stereos are notoriously underpowered and use really cheap power amp "block" chips, so if
you want to hear how horrible solid-state overdrive distortion sounds, just turn up your factory GM
stereo, for example, especially with highly-compressed FM radio. Obviously this is more the case
with my Chevy truck with the stock dashboard radio/CD vs. someone's Caddy with the deluxo GM/Bose
system. Back to Steve's question, I would submit that for somewhere +/- $1K you can get a very good
100-150W solid-state amp and maybe a 30W tube amp -- from good but not hand-built/cult-priced
manufacturers. I would further argue that the solid-state amp is much more capable of reproducing
musical peaks to the power level that your speakers will crap out first vs the tube amp which may
run into output-stage overload, output transformer overload or power supply sagging and thus get
"warm" in both temperature and distortion -- same volume level, same room, same level of speaker
efficiency. Whether or not the listener would find the "warm" more pleasing is individual taste, but
the simple fact is that it's not more accurate vs. the dynamic range of the source material.
-- Tom Fine
----- Original Message -----
From: "Steven C. Barr(x)" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Sunday, July 01, 2007 7:56 PM
Subject: Re: [ARSCLIST] Is The Record Shop Dead?
> Also, I'm curious...does the average home tube amp have the increased
> dynamic range...?
> Steven C. Barr