by Roger Nichols
Do you remember the Kepex, the Gain Brain, the Horseless Headroom, and the
Dynamite? If you do, then you have been around audio for awhile and are
familiar with Valley Audio. Valley Audio has been around for 25 years producing
solutions for audio dynamic control. Not a company to rest on its laurels,
I offer a hardy (I couldn't resist) congratulations on their entry into
digital dynamic control.
The Valley Audio 730 Dynamap provides an entirely fresh approach to dynamic
control. Besides doing an exemplary job at the normal dynamic parameters,
they have added features that are virtually impossible with analog dynamic
processors. Besides the expected parameters such as Attack, Release, Threshold,
Gain and Ratio, they have added Range, Shape, Mix and Stereo Width to the
parameter list. The only thing I haven't been able to make the 730 Dynamap
do is get my morning paper.
The 730 Dynamap is available in two versions. The 730DD (not to be confused
with any measurements on the 50 foot woman) is fully digital in and out.
The 730ADD has all of the digital capabilities plus stereo 18 bit delta
sigma A/D and D/A converters. The analog inputs can be balanced, unbalanced,
PIN 2 or PIN 3 HOT, and ground lifted. The digital inputs available are
AES, SPDIF, and optical. Any two of the three inputs can be operational
at the same time. The second input can be routed to the KEY/MIX input. If
MIX is selected from the KEY/MIX menu, then both inputs can be mixed together
digitally.
Peak Limiter: Because the 730 is a digital device, it can look ahead to
see what is going to happen before you actually hear it. LSB truncation
in conjunction with the look ahead feature provides distortion free peak
limiting with the elimination of pesky "overs."
High Frequency Compressor (De-esser): Digital domain de-essing is one of
the best applications of the technology. High Q filters with phase correction
allows processing sibilance without turning "S"s into "F"s.
With the resurgence of analog mastering, sibilance processing has become
more important than it was for CD only mastering.
Stereo Dimension Enhancement: You can reduce the stereo separation all the
way down to mono, or you can enhance the stereo separation by up to 6dB.
I tried it on some old two track tapes with excellent results.
Digital level control: You can raise or lower the level digitally to get
the most use out of those 16 bits.
Mix: This feature lets you do some amazing things with the compressor. You
basically have two threshold levels. As the level exceeds the first threshold,
compression starts compressing at the set ratio. As the level gets higher,
some of the source audio mixes in and starts canceling the compression.
Loud peaks get through un-compressed, while the meat of the audio can be
made to sound loud without pumping.
Memory: There are 495 user programmable storage registers for settings and
parameters.
Fader Port: There is a port an the rear panel that interfaces to a pair
of faders. Internal parameters can be controlled by the position of the
faders. Great for digital fades at the end of tunes, or level changes at
the solo.
The 730 Dynamap has more parameters to set than you can shake a stick at.
It takes a while to get used to surfing around the menu tree, but once you
get the hang of it you get from anywhere to anywhere else with just a few
keystrokes.
I spent a lot of time (about a month) cruising the compressor and de-esser.
With the extra parameters added to the compression settings, the combinations
are almost endless. For me, this is a good thing. There have been many times
when I have inserted a compressor on an entire mix to see if I could get
it to sound a little louder. It would sound fine for a while, and then when
the drum fill came, SUCK, SUCK, duhSUCK. With the 730 controls, you can
set up the compressor so that things like drum fills are let through the
compressor, instead of driving down the level of the rest of the track.
This brings us to the namesake processing option of the 730, the Dynamap.
The characteristics of most compressors can be defined using only a single
ratio, threshold and gain setting. With the 730 Dynamap, you can construct
a dynamic map made up of eight segments. The segment slopes and locations
are defined by selecting THRESHOLD/GAIN endpoints. After you select the
THRESHOLD and GAIN of each endpoint, the 730 calculates the ratio for each
segment to connect the endpoints. The ratio in each segment may be greater
than 1:1 (compression) or less than 1:1 (expansion) depending on the endpoints
you select.
The High Frequency Compressor is used mostly for de-essing. There are three
listening modes to help you set up the de-esser for optimum operation. The
NORMAL mode allows you to listen to the broad band product with de-essing
active. The TUNE mode allows you to listen only to the compressed high frequency
band to help you optimize your settings. The INVERT mode suppresses the
broadband signal 24dB and the compressors operation is inverted. This causes
the level of the effected band to increase as it crosses the threshold making
the problem area jump out so you can further fine tune the parameters.
The 730 Dynamap also has a mode called STATIC. No, it doesn't add clicks
and pops to your audio. In this mode there is no dynamic processing. This
is the mode that allows you to adjust the stereo field width, input and
output levels. The KEY/MIX input is also adjustable in this mode, allowing
you to mix in another digital signal if needed. The MAIN IN, KEY/MIX IN,
and OUTPUT levels can be changed in 0.5dB steps from 0dB to mute. The STEREO
WIDTH can be changed from +6dB to -71.5dB to MONO in 0.5dB steps. I haven't
figured out exactly how they do it yet, but the +6dB position actually does
widen the stereo image. On the oscilloscope it does not look like the phase
relationship is getting out of hand, so I would not be against trying this
on some old mixes I want to spiff up.
To recap, the 730 Dynamap is a great sounding piece of equipment. The converters
sound good enough to use as your main A/D D/A for critical listening. Nice
and smooth. If you have any doubts about using a digital compressor on analog
material because of the extra conversions, forget about it. These conversions
won't get in your way. Don't forget that you can use an analog source to
key the dynamics on a digital signal, or vice-versa.
If you have ever sat in front of a compressor saying to yourself "I
wish this thing would...", well this is just the puppy that can.
If you don't have room in your rack for the 730, don't worry. With the polished
Stainless Steel chassis, you will want to put it out on top where everyone
can see it. Good work, Valley Audio, I can't wait to see what's next.