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Curio's
- Calrec,
the "Valve" years
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Mention
the name "Calrec", and excellent
quality, "British built",
Broadcast/Recording Consoles come to mind.
However, back in the 1960's, Calrec were also
known for being a manufacturer of professional
"Studio" quality microphones (Oh, for
the good old days).
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The
name "Calrec", is derived from Calder Recordings
Ltd
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Calrec
manufactured a vast range of studio and
stage microphones over the years, both dynamic and
capacitor types. One
of the most famous products,
being that of the original "MK3 Soundfield
Microphone". This was used, together with
it's 3U 19" rack style stand alone
"Control Unit", to capture the natural
ambiance of a recording venue/location. This kit
being produced back in 1981/82.
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The
FC-1200 microphone, manufactured by
"Calrec".
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However, the
relationship with microphones,
started long before then .......
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In
the mid' to late 1950's, a then "Unknown"
group of Hi-Fi fanatics (Percy Hopwood, Ken Ellis,
Clem Beaumont, Ken Farrar, Howard Smith) constructed a valve
microphone for recording local musical events.
This being a single
diaphragm type, with a fixed polar pattern.
Towards the end of the
50's a "back to back" capsule was
constructed and used together with a 6072 type
valve, to form a variable pattern microphone. Not
too dissimilar to the AKG C12. Measuring some
2" in diameter by approximately 12"
long. More "one off" microphones were to
be constructed, for use in the "Friends"
own studio/recording facilities. A stereo
microphone was designed in 1968, using the same
type of back to back capsules. All of these microphones
used a "Cathode Follower" type of out-put stages.
Whereby, there is no out-put transformer required
and the out-put impedance is sufficiently low
enough to drive quite long cables, without too
much loss of high frequency information.
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The C41
valve microphone
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So,
in 1962, the Calder Valley Sound Recording company
(C.V.S.R), produced their first commercial
microphone i.e. the C41.
Originally being called the type 4 condenser
microphone. Being of a
cheap, yet reliable design, this small (6.5"
long x 1" diameter) pencil type microphone,
was aimed at the recording enthusiast market. Based around a 6072 valve and
C.V.S.R's own capsule, either the 4O type
"Omni" or the 4C type
"Cardioid", all neatly fitting into the 1" diameter
housing tube. Again, the out-put stage, was designed
around the cathode follower principle.
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The 1200
series
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Their
first "Well Known" valve microphone manufactured,
would be the Fi-cord 1200 i.e. the FC-1200. A
design based around a medium sized
"Inter-changeable" capsule, and Nuvistor
electronics, using a matching transformer in the
out-put stage. From a maintenance point of view,
the design is a real nightmare. Other then the
Nuvistor and matching transformer, the majority of
the components are encapsulated in epoxy
resin.
Thus, if a component fails within the encapsulated
section,
there is very little that can be done, other than
an expensive rebuild. The microphone was of
professional standards and used cannon type
connectors, rather then the DIN type used on
Calrec's (C.V.S.R's) earlier valve microphones..
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A
cheaper version, of the FC-1200, was produced more
for the
semi-professional market. The electronics, of the FC-1200A,
were identical in specification
to that of the FC-1200. The only real difference being, the use of a "Fixed" Cardioid capsule
with built-in bass roll-off and windscreen. This
would help to keep production costs down and,
therefore, retailing for less then cost of the
FC-1200.
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The "Fi-Cord"
connection
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So,
why use the "Fi-cord" name and not "Calrec" I hear you ask ....
"Fi-Cord", a Swiss company, knew of the
"Excellent" developments taking place re microphone production
by Calrec, and asked if they could
produce a microphone to sell under the "Fi-Cord"
name. As Calrec had no real distribution at this
time, the offer was willingly accepted. This
was in the early 1960's. Various
microphones were produced under the Fi-Cord
name. Sadly this was to be
short lived. In 1966 "Fi-Cord
International" had financial difficulties and
this would be the end of the Fi-Cord connection.
Remaining models of the FC-1200 design, were sold under the
Calrec name, these being the "Original"
valve CM1050 type microphones.
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"End
of the valve Era"
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In
1965, tests were being carried out by Calrec, into
the use of "Field Effect Transistors" (FET's)
in their microphone designs. Later, in 1968, a FET version of the
FC-1200 was produced,
designated the FC-1200T.
This was to be more of a "Modification"
to the existing 1200 type microphones, rather than
the production of a new model.
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During the mid'
1960's, we saw the introduction of the professional
1000 series microphones, using FET electronics,
to replacement for the then "Obsolete"
Fi-Cord 1200 and 1200A
models. This was to mark the end
of an era for Calrec's association with valve
technology, but only just the beginning, of the
success associated with the semiconductor models to follow.
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A
"New" Valve microphone body !
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Alas,
this not a "Calrec" design, but one of
my own. Calrec microphone manufacturing
discontinued many years ago. The "Missing
Link" RMB-2021
is a "Valve" version of the FET CB20 and
CB21 microphone bodies.
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For
more information on the RMB-2021, please refer to
the "Replacement
Microphone Body" page.
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Note
- See "Calrec
- Some Old Favorites" for more
information about Calrec FET type microphones.
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