Servicing a Studer A80 2 Track 1 inch Master Machine
This huge racked machine has been in a studio for years and after being in a small fire within the studio
had suffered smoke damage throughout..
Faults: Well where to start - motor rewind and FF spuradic - mechanical squarks from the braking systems,
Meter bridge not functioning, record and replay not level and dull, Hum from the LH channel @ 30ips, intermittent
noises coming from same channel noted on the master desk level controls - all in all not good.
It took 4 of us to lug this beast up some narrow stairs into my van! It took me and my jolly giant neighbour to get
it out again and into the workshop.
Firstly, mechanicals were looked at - the motor spooling being of particular concern. Due to the smoke damage all round
the trusty compressor was used to blow out the machine thoroughly. This not only filled the workshop with dust and muck
from years of neglect but also made a good start on cleaning all the parts from the surface smoke damage.
Top plate removed - a sorry sight of rusty brakes - heavily greased motor spindles and the usual ceasures of all moving
mechanical parts. Degreasing, cleaning rust away, re-oiling, adjustments - and a much happier sight under the top deck plate.
The heads were thoroughly cleaned - Pinch Roller refaced - transport rollers cleaned and re-oiled - looking better now.
Under the deck are the cards associated with with PSU, motor controls etc. Individual inspections of each section showed
that the machine had suffered from minor explosions in the past with the 6 x 0.47uf "catch fire" capacitors commonly used in
Studer and Revox machines. These and their associated burnt resistors were replaced and voila - the motor controls became
Each of these cards had their multitude of Electrloytic and Tant Capacitors replaced too - a good ploy as they
were all originals - and showed signs of age throughout. The mains kettle 'plocket' supplying the bridge was also replaced
as someone had previously taken a hammer to the plastic surround and it was highly dangerous.
Now for the bridge which is the early model housing Oscillators, Record amps and Playback amps as well as Meter Drive.
All Tants and Electrolytic Caps have now been replaced with new models - and now for the setup.
The VU meters do work - so attention to broken adjusting pots - setting them up for cal brought them back working in all modes.
High speed bias adjusted, play levels adjusted, record levels adjusted - now similarly for the low speed.
The bridge has Low and High frequency EQ adjustment for both speeds - with some critical listening - these came into their own too.
Re-delivery back to the studio - some final tweeks to the bridge audio level controls to bring the machine in alignment
with the master desk.
Lovely, lovely machine - it sounds wonderful - gone are the noises we don't want - gone are the hums - gone are the intermittent
Just a great sounding machine which made everyone smile. The Heads are superb with years of life left in them.
Job Done! This Mastering machine now operates beautifully -