Professional recordists know that for
long-term stability and performance successful tape transport design must begin
with the chassis frame itself. No matter how smooth-running the motors and
highly-refined the heads, since both are referenced to the recorder’s frame,
any long-or-short-term flexing or imprecise machining in the chassis will
inevitably degrade performance. To achieve the required stability – at a weight
compatible with home use – the Revox B77 uses a sturdy aluminum die-casting for
the chassis, headblock, pinch roller and mechanism, and each mounting point is
painstakingly machined for extraordinary tolerances. The Nextel-coated case
around the transport provides a similarly sturdy layer of protection for the
mechanism.
Studer-Revox
manufactures its own drive and winding motors so their characteristics can be
optimized for recorder use. For example, when heavy reels must be started up
from rest they must be fed initially with a higher starting voltage, which is
gradually reduced via a triac circuit to normal running voltage. The entire
operation must be entirely smooth or the tape could snarl or stretch. Studer
motors and controls are one reason why our decks are so widely acknowledged to
be the gentlest-handling you can own.
The capstan motor employs a
precision-machined set of teeth at the circumference of its motor. As the motor
turns, these teeth create a series of pulses that are read by a tachometer head
and whose rate is compared against the frequency of a stable internal
oscillator. In this way, even very slightest speed variations are immediately
detected through a fast-acting servo system. To reduce wow and flutter even
further, the direct-drive capstan shaft is machined to an accuracy of one
one-thousandth of a millimeter, is hard chrome-plated and is artificially aged
during the manufacturing process to ensure long-term stability.
Studer tape
heads – from 1 to 24 track models – are world-renowned and are designed and
build in our own facilities. The head cores are made from a physically hard,
magnetically soft metal allay called Revodur, which has nearly perfect
electromagnetic qualities. Whether you purchase your B77 in a quarter- or
half-track stereo format its heads will be built to the same standard of polish
employed in our professional studio decks.
The head
nest of the B77 also contains space (1) for the inclusion of a fourth head, to
be used for slide-projector synchronization or other audio-video control
purposes, in addition to the regular erase, record play units. An infrared
sensor within the head area (2) actuates automatic shut-off in the event of
tape run-out or breakage.
Because the record and playback heads of
the B77 are individual, separate units, each can be optimized for its specific
function. A narrow gap is employed for playback to extend the frequency
response, while a wider gap is employed during recording to ensure full
penetration of the oxide layer on the tape. Since the record and playback
electronics are also separate, this permits you to monitor the recorded result
a split-second later, making direct comparison possible to avoid the
possibility of an unsatisfactory recording. The sophisticated electronics and
separate heads of the B77 also permit various special recording effects.
Without external components or cables the Revox B77 can:
·
Duoplay, where both recorded tracks are
used simultaneously but for different, interspersed information, as in language
laboratories.
·
Simuplay, where a running commentary
musical part, or translation is recorded on one track and a synchronized
musical part or other accompanying material is recorded on the other.
·
Sound-on-Sound, where a single individual,
by playing various musical parts and successively mixing his live part with a
previously recorded section, can build up an entire performance.
·
Sound-on-Sound, where a single individual,
by playing various musical parts and successively mixing his live part with a
previously recorded section, can build up an entire performance.
An accurate splicing block and non-magnetic
sheertype cutter are build right into the front panel of the B77, encouraging
creative tape editing. Additionally, a lever switch is included that activates
the playback amplifiers during the fast-winding modes, and shifts their
operation to a pulse-type control. In this way you can quickly shuttle back and
forth between fast forward and rewind to find the exact point at which an
editing cut is to be made. For even finer-pin pointing of critical cuts the
reels can be rotated manually while the tape remains against the playback head.