The Revox A77 MKIII offered design changes to the previous models which were noticeable both internally and externally.
CLICK HERE to view the A77 MK1 description
CLICK HERE to view the A77 MKII description
CLICK HERE to view the A77 MKIV description
The MKIII's most noticeable change was the dark control panel and white position markings on the inner clear rotary switches. All controls
were in the same positions as both previous models - so no chassis changes had been made - but the asthetic look of the unit was now totally different.
By the time of the MKIII, the Studer motors had a re-vamp with round air-cooling cutouts on the rear of the rotary flyweels - with a new thicker
wire structure loom and colour coding structure. The motor concepts and voltages were still the same - ie: 3 phase 110Volt AC so they were still
backwards compatible for exchange to the earlier models.
Internally, the boards within the A77 MKIII had also had a re-vamp. Most of the stacked boards connecting to the motherboard had a new
fibreglass board structure with green coating on the circuit side. Examples of the change are shown on the right - the lighter coloured board is
from a MKIII and the darker brown board is from a MKII. Notice that Revox still used the same board layout (and presumably the same UV masks), but
the look and feel of the cards is more pleasant to work with. More up-to-date components had also been installed - diodes are smaller,
resistors show design changes etc.
A slight change to the Motor Servo Control Board was made on the MK III. It, too, was made of the new green coated fibreglass, but it had
slight changes to the connection pin layout. Newer versions of the Bridge rectifiers were also present.
Oh, and the Meters had been changed to `Silver Backed` units with an illuminating bulb while the unit is on. The Record lamps now
shine through the red lenses within the meters when in Record mode too.
As with all Revox A77s the MKIII was available with 2 tape formats - the 1/2 track (2 track) and the 1/4 track stereo (4 track).
Please CLICK HERE to refer to the `Tape and Track Formats` page for a more in-depth description of track use.