The floorQ Compressor is a unique recreation of the sort of photoelectric
compressor used by record producer Joe Meek in the 1960's. Using
modern components for consistency and reliability, it nonetheless
reproduces faithfully the same punchy sound that was so characteristic of
the pop records of that time.
Compression Ratio
What?? OK, it's simpler than it sounds. If the input gets 10dB louder but the
output only increases by 5dB then the compression ratio is "2 to 1". If the
input goes up 10dB but the output only goes up 1dB, then the compression
ratio is "10 to 1". In a theoretically ideal compressor, this ratio is the same
for any size of signal above the threshold but for that to be true, the gain cell
and its control circuitry must be perfectly linear over a very wide range. In
practice only compressors based on VCAs and digital potentiometers are
likely to behave in this way.
Some compressors have a control to set the ratio anywhere between 1:1
(ie: no compression), and 20:1 (which would be regarded as a "brick wall
limiter"). In the floorQ the "Slope" or "Compression Ratio" is variable from
1:1 (ie: no compression) to 10:1. However that's not all there is to it.
Variable Ratio
In the Joemeek optical compressor the compression 'threshold' is not
clearly defined and the compression ratio varies with the amount of
compression applied. Suppose the 'SLOPE' control is set half-way (5:1).
For signals only just exceeding threshold, the ratio is little more than 1:1.
As the compressor is driven harder, the ratio rises to 5:1, at least up to a
point. It is a feature of the Joemeek compressor that the compression ratio
actually reduces again during large transients and, adjusted correctly, this
helps to retain brightness that is often lost with other types of compressor.
This is why vintage compressors often sound more lively than their modern
counterparts.
So now let's see what the controls do...
‘COMPRESS'
sets the level of signal (the "Threshold") above which the
signal starts to be compressed. Turning the compression control clockwise
lowers the compression threshold, and drives the compressor harder.
'SLOPE'
sets the average compression ratio applied to signals above
threshold. Lower settings (anti-clockwise) have less effect. Turning the
control clockwise increases the ratio and makes the effects of
compression more dramatic. At maximum (10:1) ratio the Joemeek
compressor effectively becomes a limiter.
‘ATTACK'
sets how quickly the compressor reacts to peaks above
threshold. Turn this control anticlockwise for a quick response. Slower
(clockwise) allows the fast leading edge of percussive sounds to pass
uncompressed for a moment, before the compressor reacts to control the
gain. This example of "changing the envelope" of a sound makes
instruments sound more percussive. Settings around mid-position are
used where the compression needs to be less obvious. Faster attack times
(anti-clockwise) in conjunction with large amounts of compression, result
in extreme "pumping" effects.
'RELEASE'
sets how long the compressor goes on squashing the sound
for, once the signal has dropped below threshold. If it stopped instantly
there would be very noticeable modulation or "pumping" of the sound.
Generally, the longer the Release time, the less obvious is the
compression. Of course some "pumping" might actually be desirable as a
special effect and that is another way in which the envelope of a sound can
be modified. The floorQ Release is variable from 0.1 seconds up to 3
seconds giving a wide variety of effects.
'OUTPUT'
sets a static amount of amplification, to restore the level of the
signal after compression. Correctly adjusted, there will be no change in
perceived volume as the footswitch is operated.
How the compressor behaves depends on the style and volume of playing.
So experiment with the controls with different kinds of material to discover
the range and depth of effects that can be achieved. Use the footswitch to
compare compressed and uncompressed sound (blue LED lights when
active).
Compressor - cont'd
This is the all-important front end to the floorQ. Its job is to accept any type
of instrument and make it loud enough. It has a very high input impedance,
making it suitable for all types of guitar pick-up, including piezo (crystal)
acoustic pick-ups.
There is just one control, 'INPUT', which covers a range of amplification
from 0dB (unity) to 20dB. This accommodates the wide variation in levels
that come from different kinds of guitars and acts as a level matcher
between guitar and guitar amplifier.
It is active whether or not the Compressor is turned on, so that the floorQ
always sends the correct guitar volume to the power amplifier.
The preamp is an extremely high quality, low noise, Class-A design that will
be appreciated by audiophile musicians and engineers looking for a clean
sound.
Preamp
The JOEMEEK floorQ is a professional studio compressor in compact
pedal format. It takes an instrument such as an electric guitar or bass
guitar, amplifies it, compresses it and restores average volume after
compression. floorQ
give
the
gloss of a professional studio production to all your performances. It is
equally at home both live and in the studio.
Think of the floorQ as two separate items of equipment:
A Preamplifier
A JOEMEEK Optical Compressor
Simple to use yet extremely powerful, the
will
!
!
Compressor
The PhotoOptical Compressor is what gives Joemeek products their
unique character. Its job is to make quiet sounds louder and loud sounds
quieter, or in other words to reduce the dynamic range of the programme
material. It's a bit like manually riding the volume control, except the
compressor does it automatically, responding far quicker and more
accurately than you ever could by hand. The compressor is applied in
several ways:
1. Make Instruments Stand Out
Because compressors make loud sounds quieter, you can boost the
volume of the quiet bits without the loud bits getting even louder. That
means you can raise the average level of an instrument in the mix, which
has the effect of lifting it and bringing it forwards. This makes an instrument
sound denser and playing seem more even, for "produced" results!
2. Protection
Fast response times are used to control peaks. In other words if an
occasional peak sticks its head above a maximum permitted level, the
compressor clobbers it; this is known as limiting and a compressor
designed solely for this purpose is known as a Limiter. Limiters are used to
protect recorders, loudspeakers and peoples' hearing from overload.
3. Modification
A compressor can change the dynamics, or "envelope" of the instrument
and it is here that the Joemeek Compressor excels! A common use for this
is to increase sustain without adding distortion.
Types of Compressor
Most compressors work in essentially the same way: a volume-controlling
element or "gain cell" is inserted into the audio signal path. The level of the
signal at any given moment is measured and that information is used to
control the gain cell. So if the signal gets bigger, the volume is turned down.
Various types of gain cell in common use include FETs, valves (tubes),
light-dependent-resistors (photoelectric - that's us), digital potentiometers
and voltage-controlled-amplifiers, better known as VCAs.
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Overview
