by Rob-NYC »
Wed Mar 11, 2015 12:02 am
Ron, no Cobra after 2400 -all Sonotone 8T until 2700. IMO: The Cobra was obsolete for 45's before it was ever used.
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"Wingnut" This is a typical problem on these machines.
Some suggestions:
Make sure the arm is balanced reasonably well. Put the mech in play mode with no record and power off. Tie a piece of thread around the tonearm and the bracket where the spring is attached (behind the arm). At this point the arm should be free and not toughing anything. Adjust balance via a screw at the right end of the arm:
http://s1192.photobucket.com/user/Rob-N ... rt=2&o=116Another area to check is the tendency toward biasing caused by tonearm wires (As Ron mentioned) and loading from the trip switch.
I flip or remove the keeper that holds the trip sw whisker off the tonearm tail as seen here:
http://s1192.photobucket.com/user/Rob-N ... ort=2&o=70 Read description.
The simple bearings, trip switch and arm mass make for a fairly crude tracking arm and thus the choice of cart is important. In the past I used Pickering magnetic similar to the V400 series. The lowest reliable tracking weight I've achieved with these arms is 3 grams. As a practical matter the cart you choose should be comfortable with 4 gram VTF and not too compliant. "DJ" type carts are good for this sort of application.
Rob-NYC
"If we believe absurdities, we shall commit atrocities" -- Voltaire