8
Trouble Shooting
The speed stability of your deck should be
excellent once everything has settled down in a
listening session i.e.:
•
The power supply and switch box have been left
plugged in on standby for 15 minutes
•
The platter has been turning for 2 minutes
•
The cartridge has been on the record for 30
seconds
Bear in mind that the ear detects when music
is playing slightly slow much more easily than
it detects it playing fast. For this reason most
manufacturers set their decks to run slightly fast.
You can expect a bit of speed variation when
the motor is first switched on - it takes about 2
minutes to warm up properly and then the motor
should run at its correct speed but only when the
stylus is on the record.
It is highly preferable to keep the power supply
plugged in at all times (unless you are away on
holiday) because it takes a good 15 minutes to
warm up from cold and run correctly. When in
standby mode the control box draws a negligible
current so you need not worry about your
electricity bill.
If you keep switching the deck on and off you
will get a little speed variation as it takes approx
2 minutes to warm up the circuit each time even
if it’s only switched off for 3 seconds. This is
unavoidable although we have tried to design out
the variation as much as possible.
If you measure the speed within 30 seconds of
putting the needle on the record the speed will
not be perfect as it takes a while to settle down.
Some people make the mistake of constantly
watching the speed before the deck has
settled down and the needle has been on the
record for a good 2 minutes. Strobes are very
accurate and the slightest speed variation is
picked up. 0.03% variation is observable.
Speed Variation Trouble Shooting
If there is significant speed variation then causes can be down to the following:
•
Significant changes in room temperature (this affects decks which use thick, viscous oil in the bearings)
•
Lack of oil in the bearing, check by adding oil
•
Changed belt tension
•
An oily belt / sub-platter, clean running surfaces
•
Turntable out of level, this affects the main bearing friction
•
After adjusting the tension of the 3 small Philips screws which hold the motor on you may need to
re-adjust the speed as they affect motor tilt very slightly
•
Check the sub-platter is not fouling on anything, on certain decks it can rub against one of the spring
covers. It has also been known to “bottom” against the top of the bearing house, there should be about
1-3mm clearance between the top of the bearing house and the bottom of the sub-platter
•
A dirty bearing that exhibits too much friction. The sub-platter should drift round effortlessly with the
slightest of nudges and go on spinning. If you suspect the bearing friction to be a little high return, talk
to the manufacturer
•
A worn thrust bearing
•
Transistors that have developed temperature instability
