1. INTRODUCTION
Congratulations! You are the proud owner of the UTA UNFa-1 UnFairchild Accessory unit that
adds a whole new world of control and flexibility to the UnFairchild 670M mkII.
To get up and running right away with your UNFa-1, skip to Chapters 2 (Powering Up), 3
(Rack Mounting), and 4 (Front Panel Controls). The most vital information about the proper
installation of the UNFa-1 in this manual is in Chapter 3 (Rack Mounting). The rest of the
manual contains more detailed information that is not essential for understanding the
unit’s basic functionality.
The UNFa-1 is a collection of new features, some of which I always knew I wanted on the Un-
Fairchild and some of which I discovered I wanted on the UnFairchild after years of use. I always
knew I wanted a built in HP filter for the side chain and a WET/DRY mix control but there were
already so many new controls on the UnFairchild that I felt it was better to save them for an op-
tional add on. The WET/DRY mix requires adding an additional active gain stage that didn’t exist
on the original Fairchild and I felt permanently adding it to the original UnFairchild unit would
stray too far from the mission of faithfully recreating the integrity of the Fairchild circuit. These
additional feature would also drive the cost higher on a unit that is already on the very high end
of the world of high end audio gear. I didn’t want people paying for features that they might not
want or never use and were never on an original Fairchild.
The Feedback/Feed Forward blend control is something I discovered in my travels with the Un-
Fairchild 670M mkII as I explored using it on absolutely everything. It is by far my favorite of
the new features added with the UNFa-1. I was enjoying the incredibly aggressive compression
character you can achieve with the Feed Forward splitter cables but found that, at times, it was
difficult to find a setting that wouldn’t over compress on some sections while under compressing
on others. I started experimenting with blending Feedback and Feed Forward externally on my
console. The results were immediately, massively satisfying but the setup was complicated and
cumbersome. I knew I wanted this feature to be more effortlessly available.
I realized that it was impossible to do Feed Forward compression at the same time as either of the
M/S modes. There were times when I needed to do this, so that is fixed with the M/S mode switch
on the UNFa-1. There were times when the simple approach of “loudest channel takes over” ste-
reo linking was unforgiving when you have extreme differences in the left/right source material.
The “AVG” mode addresses that issue.
I will get into detailed explanations and examples on how to apply all of these exciting new fea-
tures later in this manual!
-Eric Valentine
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