Buzz Audio SOC1.1
An opto
compressor that’s light years ahead? Sean Diggins feels the
buzz of excitement.
Being a double bassist, I’m
always excited when the opportunity presents itself to check out a
good optical compressor. There’s something inherent in the non-linear
characteristics of the best optical compressors that results in rich,
euphoric sweetening of the of the audio along with musical dynamics
control. Classic optical processors such as the Teletronix LA-2A are
famous for turning a good sounding bass track into a great sounding
bass track, but good quality optos are also an excellent choice for
many other instruments, voices (countless hit singers, in the case
of the LA-2A) and in rare instances, two-bus (or master stereo bus)
compression. With the LA-2A, probably the classic compressor, the
inclusion of four vacuum tubes and purpose-built impedance matching
transformers is a big factor in the sound, but certainly the optical
components also play a big part. That said, there’s been a flood
of cheap (and often messy) optical compressors onto the market over
recent years, so it’s a delight to discover a beautifully crafted
device being designed and hand built just across the Tasman in New
Zealand.
Buzz Audio was formed in Wellington in 1985 by Tim Farrant, a widely
experienced engineer/designer and systems integrator who saw a need
for high-end consulting within New Zealand. Just four years later,
he was joint winner on the NZ Music Awards Engineer of the Year Award.
Realising he had the skills and desire to build high-end hardware,
in 1990 Tim released the first Buzz Audio dual-channel microphone
amplifier. Over the next eight years Buzz Audio continued to refine
the design of this amplifier while developing other high-end products,
including the first version of the Stereo Optical Compressor. The
products were very well received (a quick read of customer responses
at www.buzz-audio.com is testament to this) and work gradually spread.
I was directed to Buzz Audio years ago by a Kiwi mate on the PC-DAW
e-mail list, but had never managed to find a unit to audition. A bit
like Australia’s wonderful Sebatron company, the customers tend
to find Buzz Audio from referrals, rather than splashy, expensive
advertising and retail marketing. This is possibly set to change in
Oz, with the company quite excited about inking a deal with a new
Australian distributor GBG Technology PTY Ltd.
Compression 1.1
My first visual
impressions of the SOC1.1 were promising. Housed in a sturdily constructed
matt black 2U rackmount case, the unit has a distinctive ‘old
school analogue’ appearance, offering sensible large knobs which
are reminiscent of the famous Sifam knobs, but are actually classic
knobs from Swiss manufacturer Elma. Two large VU meters dominate the
rest of the front panel, along with eight robust metal toggle switches.
We’ll examine the various knobs and switches later. The rear
panel is simplicity itself, housing four balanced XLR sockets and
the power socket.
I got together with John Galbraith,
a very experienced engineer and technician in Perth, to check the
innards of the SOC1.1 for parts and build quality. We weren’t
disappointed. It’s not easy to elicit approving noises from
John, but he was certainly nodding and making all the right sounds
(yeah… hmm… right!… very good… this is a good
unit…) as he showed me around the hand assembled electronics
and described how it all works. The first thing we noticed was the
neatness – nothing out of place, no extraneous wiring flopping
about and plenty of breathing room (for a repair tech to fossick around
without breaking anything?). Straight away we noticed the smart use
of LED rows in arc formation to light the VU meters, an excellent
way to reduce heat and prolong meter life (and which also happens
to look great). A black tube beside each meter contains a simple opto
device used in the gain reduction metering circuit which Tim claims
gives a more meaningful response. The circuit boards are high quality
and the Analog Devices opamps (OP275) are well respected for high-end
audio as they run on +20V rails and provide plenty of headroom. Two
big, mysterious black cubes contain Buzz Audio’s proprietary
optical components, each enclosing an HP Quad LED light block shining
onto four Light Dependant resistors. Apparently Tim spent months beavering
away on the design, so no wonder it’s all sealed up and well
hidden (aside from the need for a darkroom). There are some wire ribbons
in the unit, but these aren’t used for program audio, instead
providing a path between the output gain control and the feedback
of an opamp stage. The power supply is a good quality toroidal. Having
satisfied ourselves that the unit is built with loving care, John
fired it up, had a smoke, then inserted it between some gnarly music
and a car speaker… turned a few knobs and declared it a great
compressor! And this is a man who loves good compression and literally
knows them all inside out. So off I wandered back to my studio, keen
to do some real work with this unit.
Back to the Studio
In the half light of my studio, the only real gripe I have with the
SOC1.1 became immediately apparent. The front panel labelling is small
(for this 43 year old, anyway) and nigh on impossible to read in a
dimly lit room, but it’s worse if you install the unit below
eye level. The big knobs are great, but the labels are inscribed beneath
the knobs – if the unit is more than slightly below eye level,
it needs to be tilted up to read the labels, which isn’t always
possible in a rack. That said, there are only a few controls to learn
and in wasn’t long before I didn’t need labels at all.
The front panel is a twin configuration with separate controls for
each channel. Each channel features a lovely VU meter, a large ‘drive
knob, which acts kind of like a threshold control in reverse (i.e
clockwise for more compression) and a large output knob which ranges
from OdB to + 15dB. The output seems sort of logarithmic, as the first
50% is only 5dB, probably to allow precision settings. This is where
the controls would end with a vintage optical compressor, but modern
optos usually offer further controls. In the case of the SOC1.1, two
smaller detented switch-based knobs control ratio (2,5,10 or 20:1)
and release time (1, 2, 4, 8, 16 or Auto). The release times are in
100’s of milliseconds (i.e. 4 = 400ms). An extra touch specially
developed by Buzz Audio is a switch which selects between three available
attack settings (slow, fast or auto), while another switch toggles
true bypass of the SOC1.1 audio electronics (a nice addition). A third
switch selects between the three VU meter modes (input, gain reduction
or output). Finally, two switches to the right toggle power and stereo
linking. Interestingly, when linked, all controls remain operational
and the two channels must still be set up individually, even though
the side chains are linked. This is actually a nice touch if used
carefully, as it gives back control which is usually given up as a
result of linking.
All a Buzz
Within a few minutes of playing my custom Scott Wise acoustic guitar
through a vintage Quad 8 mic pre into the SOC1.1 I was desperately
trying to figure out how to hide buying it from my other half. No
way could I afford it (building a new house and studio has put a complete
stop to new toys), but no way was it leaving! All it took was a 2:1
ratio, slow attack and auto release, plus a few dB of compression
and the guitar initially sounded exactly how I’d always imagined
it could sound. War, round and silky smooth, with a scintillating
percussiveness that had me lost in reverie for the next hour or so.
I tried all sorts of settings and really had trouble making it sound
bad – even serious squashing was palatable –it was ‘wrong’
but it had a nice euphonic character which still made it interesting
and listenable.
For a week or so I recorded
a variety of vocals, guitar and double bass for a forthcoming release
and the SOC1.1 was a constant delight to use. The VU meter ballistics
are good (especially in dim light) and configuring the unit is an
absolute doddle, although it needs to be said the meters are subject
to the usual VU meter averaging. Mostly, it was simply a matter of
choosing appropriate settings and dialling in the drive knob until
the desired result was achieved. And when your hardware is good, “the
search’ is usually short and sweet – almost invariably,
I found the ‘right’ setting in less than a minute. Double
bass was a revelation, especially when using the classic auto attack
setting, which most resembles older optos like the LA-2A. When using
this setting, the attack time changes according to the amount of gain
reduction in the program, which really seems to suit my whacko double
bass technique. By cranking up the pumping, I really felt like I was
in Jim Dickinson ‘super compression’ territory (G. Love/Mudhoney
turf, for those yet to hear his productions), where even the blats
sounded sweet. Similarly, I recorded a weak vocalist and a strong
vocalist and had excellent results from both, thanks in no small pat
to the auto attack setting. Due to the opto design, the unit has an
inherent soft knee characteristic – this suits me perfectly
as I generally prefer soft over hard knee in the majority of recordings
I work on but it may not cater to everyone’s needs. In this
respect, it needs to be said that an optical compressor is not an
all purpose workhorse to cover all your dynamics needs. If you can
only afford one high-end dynamics processor, you may be better off
choosing something more flexible, such as a Distressor.
Acting on a suggestion from Tim, I spent a bit of time with the SOC1.1
inserted over the master stereo bus on a variety of mixes. Mastering
engineers usually avoid optical compressors over the L/R bus because
of the imprecise nature of the optical components and the slow attack/soft
limitations. Optical compressors often have a distinctive ‘sound’
or colouration as a result of fast transients beating the gain reduction.
Combined with the variable attack and release characteristics when
using ‘auto settings. Additionally, most of the classic optos
were mono! However, the SOC1.1 design incorporates a proprietary technique
designed to speed up the attack when needed and it certainly seems
fast enough for many styles of program audio. Used wisely, I see no
significant impediments to the SOC1.1 being used on the L/R bus and
found it to be transparent and musical, although the stereo linking
requires a good deal of finessing when mastering. The hard bypass
is a nice touch (as long as you switch both channels at once!) and
I’m looking forward to spending more time working with the unit
as a bus compressor, but it really seems more suited to tracking instruments
(especially drums, acoustic guitar and bass) and vocals.
Buzz Audio is obviously a company which cares about quality. Here’s
hoping the Buzz name achieves more recognition in Australia –
on the strength of the SOC1.1 the company’s forthcoming voice
channel should be one to watch out for.
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An
Interview with Buzz Audio founder, Tim Farrant
Sean Diggins: What are the hurdles
you face by being in NZ?
Tim Farrant: I suppose one would be travel, with the main markets
in the US, UK and Europe, getting there to attend trade shows and
meet distributors and customers is very expensive. Another is the
cost of advertising in the major magazines given the NZ exchange rate.
SD: Have technological advances made it easer for manufacturers to
make products and sell them from ‘remote’ countries like
NZ?
TF: The Internet certainly has made a difference to communicating
with parts and component suppliers. It is possible to get quotes and
answers very quickly and it’s now possible to buy direct and
avoid distributor mark ups with open trade agreements.
SD: Why another optical compressor
TF: I’ve always liked the action of the classic optical compressor
like the LA2 and LA3 but found the lack of control frustrating, i.e.,
no attack and release or ratio controls. The idea with the SOC1.1
was to maintain the same ‘musical’ response these older
units are famous for but provide the user with more possible setting.
SD: It apparently took you a long time to develop the optical components.
What did this involve?
TF: Well, when I actually sat down and measured the performance of
the LA2 and LA3 to get some idea of how they ‘ticked’
I discovered that the attack time was quite slow and decided thee
must be a way to improve on it. A lot of time was spent on developing
this. Also, I found that the actual Light Dependent Resistors (LDR)
varied wildly from component to component, so this is the reason our
optical elements have four LDRs and not just one.
SD: How do you generally go about selecting components?
TF: We like to ensure the components we use are of good quality, especially
when it comes to switches and pots. After doing a lot of listening
to different operational amplifiers, I concluded that the Analog Devices
OP275 was a good choice for audio and even though they are relatively
expensive compared to the usual NE5532/34 or TL072, the sonic performance
is far superior.
SD: What particular applications do you think the SOC1.1 is suitable
for?
TF: It is generally regarded by many that optical compressors are
too slow for the mix bus application. Given the unique ‘speed
up’ circuit employed in the SOC1.1, I would tend to challenge
that notion! We have several users who use the SOC1.1 for recording
classical music and they find the unit excels in this application.
Generally, the compressor finds best use in tracking.
SD: How many staff are there at Buzz Audio and who does the assembling?
TF: Buzz Audio is not a huge company, we have two full-time techs
doing the final assembly, plus contract workers to assemble circuit
boards and wire looms. I try to personally check every unit that goes
out the door.
SD: Do you encourage direct contact with your customers and do you
build custom modifications?
TF: Most definitely! UI feel direct communication with end users is
important. If someone is having a problem, we want to know about it
– and as we grow, I intend to keep this facility in place. As
for custom items – just let us know what you want!
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