The legendary Mk.5
The legendary Mk.5
The Mk.5 is probably Brenell's most famous model. Launched in April
1958 with a gold 'hammered enamel' deck plate and mushroom-beige
'Rexine' covered plywood cabinet it inherited a much improved
version of the Mk.4 deck incorporating features which were standard
on the domestic 3-Star, such as a digital tape counter and
on-demand three-speed selection. It however retained the 1/2" and
1" capstan sleeves making this a belt-less, on-demand four speed
machine.
Only by placing a Mk.4 and Mk.5 deck side by side, are these
differences made obvious: no lapsed-time plate, speed selector on
left, tape counter on right, pull down non-locking pause control,
and new Bulgin black plastic, rhomboid shaped control knobs on both
deck and pre-amplifier. Hidden under the ivory head covers was a
new, separate, head block which greatly reduced assembly and head
alignment time. The standard Mk.5 used a Brenell erase and a
combined Brenell record/playback head, but space allowed the
experimenter to fit a further two heads.
There are in fact four variants. Early examples employed a right
hand tape back-tension arm and brake with BT-H 1103 motors; this
was soon upgraded to an AEI 1303 synchronous capstan motor at which
the back-tension arm became an anti-flutter arm; it was finally
removed when triple AEI 1303 hysteresis synchronous were fitted. In
its final form it adopted a Papst hysteresis synchronous main motor
with AEI spool motors and is easily identified by its new black
plastic head covers.
The Mk.5 was a truly versatile deck with its four speeds and
provision for four heads; it soon became the envy of enthusiasts in
the many competitive tape-recorder clubs which grew rapidly across
the country as tape-recording gained momentum. Many found that by
varying the size of the capstan sleeves, it was possible to create
unique pitches and soon Brenells were being used experimentally by
Daphne Oram, who pioneered the BBC's Radiophonics Workshop, using
several Brenell Mk.5 mono and the new staggered stereo decks in her
own workshop.
The Mk.V staggered stereo was first offered in the summer of 1958
and employed a pair of staggered stereo erase and record/playback
heads which allowed reproduction of the commercially made American
staggered stereo tapes. Incredibly, modern stacked-stereo remained
very much a domestic novelty for many years as professional
musicians preferred a full bodied mono. The deck was mounted atop a
large steel frame with twin pre-amplifiers on a steeply inclined
front panel; it was very heavy! Initially of 8-1/4" capacity, it
was soon joined by a 10-1/2" model in which the spool motors were
positioned nearer the corners. As the spool turntables retained the
DIN 3-wing drive, a new three piece DIN/AEG/NAB centre was supplied
to allow DIN, NAB or the original AEG centre 'pancake' open reels,
much favoured on the continent.
With the introduction in 1961 of the new Papst motored, 'grey'
Mk.5M ('M' for 3-head monitor), the 'gold' Mk.5 remained on offer
for year with an optional valve voltmeter (replacing the record
level indicator); it was briefly offered in a new blue-grey
hammered enamel finish.
The Mk.5M initially adopted Brenell's erase and record head but
with a third Bogen monitor/replay head (there was still space for a
fourth head), plus a valve voltmeter peak recording level meter
pre-amp. It was technically a Series 2, but not known as such (it
is seen here right in later Series 3 form) even though it used a
re-engineered Mk.5 deck finished in a blue-grey paint, now covered
by a large removable alloy masking plate - a theme carried over to
the remodelled pre-amplifier panel: initially in dove-grey enamel,
it soon changed to a leather-grain effect on the improved all-Bogen
head models. Unfortunately access to the deck innards was now
hampered by the mask requiring removal of all the control knobs and
mask to gain access to the deck release screws! The tape deck was
fitted into a lower profile cabinet, trimmed in a mid grey 'Rexine'
elephant-hide effect material similar to that used by Land Rover
for their seats!
AEI spool motors and a Papst main motor were retained and, in
addition to the pause control, there was a new pull down
'superimpose' button which eased the tape away from the erase head
to allow over-dubbing - it was not perfect, but with the Mk.5M's
additional ability to mix microphone and radio inputs, the
Brenell's versatility was greatly enhanced especially with the new
Bogen head array from 1962. Curiously, though the deck plate is
punched for a lockable pause control, Brenell decided early into
production that it was perhaps not such a good idea if an errant
user left the machine in that state, so the masking plate was
modified to blank off the lockable 'dog-leg'.
The Mk.5M was joined in 1962 by the new Mk.5 - now officially the
Series 2 - which shared the same cabinet and 'grey' theme, but had
a more basic Bogen 2-head configuration and simpler pre-amplifier
with a central side-on level indicator. Like all previous Brenells,
the pre-amplifier had an output stage for the internal speaker
which, with a standard Lustraphone LFV59Z microphone, could be used
for public address. With the arrival of the new model Mk.5 Series
2, the Mk.5M duly became the Mk.5M Series 2: the 10-1/2"
models were now officially Mk.510.
In 1963 a new Series 3 deck appeared. This was re-engineered to
accommodate Papst spool motors, with their rim brakes, heavier
flywheel and now with improved Bogen Universal heads; such
modifications set new professional standards in wow and flutter and
frequency response. These Series 3 models are immediately
recognisable by their large black plastic spool turntables and, on
cabinet fitted models only, by two large chromed thumb screws which
on their release allowed the deck to be raised on its rear hinge
without having to remove the masking plate and knobs!
Specials
Brenell had already produced some special purpose decks based on
the Mk.5, such as the staggered stereo. Their willingness to help
tape-recorder enthusiasts led to a specially modified replay deck
for use by patients in hospitals. Fitted with an extra long (and
much easier to operate) play control lever (the photo shows it
incorrectly fitted), it allowed patients to listen to "spoken
books" from the Hospital Library Service. These used a non-standard
tape width and a unique playback speed to prevent unauthorised home
recording. There was even an experimental two-way recording reverse
deck as well as data recording and tape-loop echo decks.
However the most significant development was the new STB1 which
appeared in 1963. This was an astonishingly versatile and mind
bogglingly complex model.
STB1 and STB2
For some time now, a Brenell had become the experimenter's machine
of choice (the Beatles had Brenell Mk.5s) but with demand for
stereo growing, Brenell recognised that musicians were in urgent
need of an affordable stereo mastering deck with basic monitoring
and mixing facilities, for which Brenell had offered a basic,
single channel microphone/radio mixer. Yet they still did not offer
a standard, off-the-shelf stacked stereo model: the short lived,
domestic 3-Star and the heavy, industrial Mk.5 stereo had long
since been dropped. They now developed a new stereo pre-amplifier
with twin edge-on meters for the enthusiast to use in conjunction
with a Mk.5 fitted with the optional stereo heads. Brenell called
this a 'Tape Link' ( bottom ) as it literally linked a stereo
recorder to an external stereo amplifier; it was developed from the
stereo pre-amplifier for the new STB1.
The Mk.5M Series 2 was the ideal platform for Brenell's first
'professional' deck, the STB1, launched in 1963. It had an
additional manually applied rewind spool brake to ensure more
consistent high-speed spooling with minimal tape-edge damage. But
of far greater importance on the standard 1/2-track STB1 was a
fourth 1/4 track replay head selected by a slide-switch (likewise
for 1/4 track STB1). In conjunction with this, up to 10-1/2"
capacity, full frequency equalisation correction and four speeds,
it was possible to work with virtually any tape format and
configuration. The new stereo pre-amplifier allowed full
sound-on-sound, echo, track transfer, mixing facilities and
variable bias levels. It was a truly awesome machine with enough
knobs to impress even the most enthusiastic school-boy, but its
mind boggling complexity required mastering new skills and a very
cool nerve - especially as it was not easy, for instance, to set
different recording levels for each track.
At the side of the cabinet was an aperture for the 1/4" input and
output jack plugs. The entire deck and pre-amplifier were fitted
into a self-contained steel cage which could be console mounted or
slid into the back of a specially modified Mk.5 cabinet/flight
case. It adopted a new polychromatic metallic green enamelled
finish and cost £120, almost twice that of the basic Mk.5, but even
at this price it was considerably cheaper than a basic professional
studio model. A 10-1/2" model was also available as was a 1/4 track
model with 1/2 track replay head.
Launched as the STB1, Brenell appears to have anticipated a Mk.2
and sure enough in 1964, following Brenell's relocation to a new
factory in Liverpool Road, London, a much improved STB2 appeared
with the new Series 3, all-Papst deck. This was even more awesome
with extra mixing facilities and now engineered to 600ohm studio
standards with each input and output capable of being configured
for virtually every conceivable piece of equipment: it at long last
had concentric track gain controls! It was also slightly longer
than the STB1 to accommodate an optional stereo valve output
amplifier in the rear of the chassis and, with optional built in
stereo speakers, it became a truly versatile mini-recording studio,
prompting Brenell to expand further into the fledgling musician and
home studio market.
The separate stereo 'Tape Link' pre-amplifier remained available
offering basic record and playback functions with upper and lower
track monitoring facilities. As with the STB, it was finished in a
polychromatic metallic green enamel with a substantial cadmium
plated steel case designed for slotting into a standard Brenell
cabinet or studio console.
Top to bottom: MK.5
Mk.5 10-1/2" staggered stereo
Mk.5M Series 3
Mk.5 Series 2
Mk.5 Hospital deck
Top to bottom: STB1
STB1 cradle
STB2-510 10-1/2"
Stereo Tape-Link