GR> While it is definately an A-77, I've no idea really what mark it may
Mark IV for the age you suggest, in the newer of two subvariants of that
series.  That means it would have a 555 based servo circuit, as opposed to an 
LC
based one.  The capstan servo motor was AC driven, but not frequency 
controlled,
as it used a DC biased shunt across a bridge rectifier to regulate whatever
torque it took to drive an inductive sensor pulse train to the right 
requency
for high or low speed.  
 GR> marks because when I had her open I'm sure I saw 1982 or something
 GR> stamped on one of the motor components, unless of couse that
 GR>         Actually, someone here may be able to tell me if this machine
 GR> has a fault, now, whilst recording the VU meters work fine, but not
 GR> during playback, is this by design or a fault?
There is a quirk to those, though I forget the details without pulling out my
own service manual.  As I recall you can work around it by setting up the
channel dub modes to display crossed channels as if inputs during playback, 
r
by enabling an option I vaguely remember a reason for not using existing.  
The Studer heads for those were pricy, but unusual in that they didn't groove
if aligned well, and maintained stable frequency response from new to gap 
nearly
worn open better than most.  
New price on that would have been about $1500, more than tripled from a 
ecade
before.  I have one of those circa 1976 around in fairly decent condition, 
nd
one older one for parts including a rack mount cage, if anyone's interested.  
Terry
--- Maximus 2.01wb
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