| AT issue 51 VU
Meters |
"It is this response time that’s
responsible for the VU meter’s characteristic display
of audio ‘volume’ rather than the peak level. An
analysis of a VU meter’s characteristic would show that
it is integrating the audio waveform, in a sense, adding up
the area drawn out by the shape of the waveform." |
| AT issue 53 Impedance |
"One of those terms we often
come across in the audio world is the word Impedance, often
quoted as one aspect of a piece of equipment’s technical
specifications. Typically quoted is a unit’s input impedance
and output impedance. So, what is it and what does it mean?" |
| AT issue 54 DIY
Repair |
"The question ‘why does
my equipment break down when I need to use it?’ is one
that’s regularly posed to me by my clients. My usual response
is: ‘If you don’t use something it won’t break,
and therefore if you do use it, it will break.’" |
| AT issue 55 Transformers |
"How then does all this relate
to transformers? Well, audio transformers have some easily quantifiable
qualities and in exploring these qualities we can find some
particular characteristics that may just be the key to generating
some of this so-called ‘warmth’." |
| AT issue 57 Decibels |
"There’s no denying that
a certain lack of technical understanding of equipment specification
and calibration exists within the audio industry today. So this
issue I thought I’d have a crack at outlining some of
the common terms of technical specification ...." |
| AT issue 57 .... the
'missing bit'! |
due to a layout error a section of
the article fell off the page
this is the 'missing bit' |
| AT issue 58 Microphones |
"While we can emulate all sorts
of instruments with quite good results these days, until someone
comes up with a 'plug-in vocalist' we will at least require
microphones for recording the voice. The human voice with which
we have an innate familiarity is often the greatest test of
a microphone's characteristics, strengths and deficiencies." |
| AT issue 61 Preamps |
"Probably the most common microphone
preamp topology found today utilises a simple pair of transistors
implemented with variable gain feeding an IC operational amplifier.
With good low-noise transistors running with variable gain in
Class-A, and an Integrated Circuit (IC) op-amp, a microphone
preamp can be built for a couple of dollars." |
| AT issue 62 Equalisers |
"Probably the most ubiquitous
equaliser on the planet is the humble bass and treble control
found on almost every hi-fi amplifier. Almost without fail,
this equaliser will be based on the original design by Peter
Baxandall." |
| AT issue 63 Electrical
Safety |
"While there are countless factors
that contribute to providing a safe work place, one in particular
that naturally catches my eye is electrical safety. So for this
issue, let’s put aside the excitement of learning what’s
going on behind the front panels of your outboard rack, and
focus our attention on the more mundane IEC socket or mains
plug on the rear. Occupational Health and Safety (OH&S)
mightn’t sound like a fun topic, but it applies to anyone
who works in the audio industry for money." |
| AT issue 64 Studio
Wiring |
"Studio wiring is one of those
tasks that should be so straightforward and predictable that
we could happily and confidently leave it till the last phase
of a studio’s construction. Unfortunately, this is not
the case. Wiring a studio takes planning and skill, yet it still
remains one of the most neglected and misunderstood aspects
of studio construction." |
| AT issue 65 The
life of a Tech |
"This issue I thought I’d
bring you over to my side of the bench, so you can see what
it’s like.
Don’t touch anything now, its dangerous back here." |
| AT issue 66 Compressors |
"The design topology of compressors
directly impacts
on the characteristics they impart to the audio passing through.
Some have a greater impact than others even when no gain reduction
is occurring." |
AT issue 68 Compressors
- the Sidechain |
" ... before we examine the
myriad control possibilities of a compressor, let’s pause
for a moment and consider how many controls such a device can
successfully live without. The LA-2A, for example, is perhaps
one of the most successful (and highly prized) compressor/limiter
designs of all time, yet it has only two controls… well
three, if you include the limit/compress switch, which, in many
situations, appears to do nothing at all." |
| AT issue 70 DIY |
"By all means push the envelope;
after all, one of the good reasons for embarking on DIY is to
gain knowledge and an understanding of what’s going on
behind the knobs. However, it’s equally important to make
sure the job’s achievable." |
| AT issue 71 Amplifiers |
"Ultimately, amplifier performance
hinges on the overall design, whether Class-A,
Class-AB, valve, transistor or FET, the synergy of the combination
of the
individual parts and how feedback is employed determines an
amplifier’s sonic
stamp." |
AT issue 73
NEVE 51 |
coming soon |
AT issue 75
Hearing |
"Hearing loss is a significant social and
health issue and some believe the increasing use of ear buds
and headphones is likely to exacerbate the issue in the future." |
AT issue 76
Troubleshooting
|
"Efficient and effective troubleshooting
is as much an attitude as it is a skill. It requires a logical
and ordered approach that is best supported by the foundations
laid down in the organisation and order of your studio or equipment
setup." |
AT issue 78
DIY Monitor
Controller |
"If your studio monitoring is currently
managed by something you inherited from your brother’s
’80s Dick Smith hi-fi, isn’t it high time you faced
the music and found a more accurate means of listening to your
system?" |
AT issue 79
iThing |
"Faffing around with cables, adapters and
cranking volume controls back and forth between selections of
different sources can easily be avoided by correctly interfacing
with any iThing that may come through the door" |
AT issue 80
What's that
noise?
|
As a teenager I’d spend hours sitting in
front of the family’s old gramophone (yes it had tubes)
playing Led Zeppelin records. My dad would walk in yelling:
“what the hell is that noise?” I wish I’d
known enough back then to say – as I lifted the needle
of the record – “I think that’s shot noise
in the !rst preamp tube!” |
AT issue 81
DIY PADS
|
The pad is one of the most obvious of audio control
functions: flick the switch and the signal level drops by the
prescribed amount; flick it again and the signal is restored.
Here we’ll explore why we need them, how to design them
and importantly how you can build your own. |
AT issue 82
Capacitors
|
Here on the workbench there’s one
electronic component above all others that I
deal with on a daily basis. Whether I’m
refurbishing an old ’50s tube limiter, repairing
console channel strips or hunting down an
intermittent crackle in a microphone, capacitors
are typically the star of the show, infamous for
causing a broad range of faults in all sorts of audio
equipment. |
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