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Re: Tubes in Pre-amps: your expertise and honest opinion.
Dear Margaret,
I'm no expert in the physics of sound but let me attempt to answer your
question about tube distortion
or noise and solid state/transistor distortion or noise from my relatively
unsophisticated understanding of it.
All recordings have noise. The reason we want to record something as
'hot'
as possible without
distortion is so that the difference between that intrinsic noise volume
and
the volume of your recorded instrument is as
great as possible. The louder you can record something without
distortion the greater the so-called
"Signal to Noise Ratio".
Since all recordings (and all reproducing systems and media) have a
certain
amount of noise, the amplification
technology you use will affect that noise and the way it sounds to your
ears.
In a nutshell, tube amplifiers produce even harmonics.
transistor (solid-state) amplifiers produce odd
harmonics
In the harmonic series, the fundamental frequency (the one we take as
the
pitch of a sound or the sound)
is thought of as the first frequency (hence odd in number).
If we take just the first harmonics in this natural series we
get
F H1 H2 H3
H4 H5...........etc.
1st 2nd 3rd 4th
5th 6th
Fund Octave Oct+5th next Octave next+3rd
next Octave
As you can see, the even harmonics are all octaves.
Because of this, they are consonant, harmonically, with the origial
Fundamental frequency and
sound smoother and more 'harmonious' to our ears.
Additionally, as the odd harmonics keep going up, they become
increasingly
disonant and out of tune.
This cause a 'harsher' sound to our ears.
Tube amplifiers do make for a smoother sounding noise floor.
For lots of reasons, the noise produced by analogue tape machines and
record players also
seem 'smoother' or 'warmer' to the human ear.
Nowadays, since almost everything you hear has to go through analoge to
digital conversion and then back from digital to
analogue when you hear it reproduced with an amplifier everything has
digita conversion problems.
Luckily, people have been clever and figured out how to do digital
modellings of
analogue sounds (tube distortion, record player noise, analogue tape
noise
(and intrinsic compression).
You can even record something with a fairly cheap
microphone..............put that recording through
a digital model of an expensive microphone.................put it again,
through a digital modelling of a tube amplifier
(and I've been using Universal Audio's brilliant plug ins that simulate
the
most expensive and sought after
tube amplifiers, compressors, limiters, etc to great
effect).................and even add digital simulations of
worn record skips and pops and fully convince someone that you found your
track at a yard sale
on an old 45 rpm single and sampled it.
Luckily, those Art Tube preamps are incredible deals for the money.
Hmmmmmm, do you buy a used Audio Technica 4033 mic ($250) with an Art
tube
preamp ($80)
that has the identical mic capsule and the
identical
12AX7A tube as the Audio
Technica 4060 Tube mic ($1,360)? Lol, you be
the
judge.
In the long run, however, I think that an audience cannot discern the
difference between me putting my microphone through
my Art Tube Preamp with it's intrinsic warm noise or through my incredibly
transparent and transistor Mackie pre amplifiers on
my mixing board. In a studio perhaps..................in headphones,
definitely, but I think the music becomes more
important than this fairly subtle difference.
Analogue music aficianados would consider that last paragraph heresy, by
the
way so you'll get lots of different advice about it.
The proof is in the pudding. Do YOU like how that Art sounds? That's
all
that matters because if you do, then
now, it is YOUR sound, for better or for worse.