by Rob-NYC »
Thu Jul 12, 2012 5:43 am
Gordo, it probably isn't necessary to replace tubes as this in not likely the cause of what you are experiencing.
The amp needs to be recapped, it is nearly 58 years old.
As for the damping, yes, it s filled into the area around the vane that the stylus is a part of. When I did this back in 1986 i used some white lithium grease. At first i added too much and the sound became dull and muffled. I used a small model paint brush to remove some and got a decent sound after a few tries. The main criteria is that the damping not be prone to hardening and not be petroleum based (bad for records and the cart's plastic). You might even try a little cotton in there instead, but remove it if you decide to use a viscous liquid afterwards.
When I bought these machines I was given a half dozen "Duotone" Cobras in NOS cases. All had dried out damping and sounded like a Morning Glory Victrola.
Again, the priority is to get this amp recapped, it is living on borrowed time otherwise. Also, check to be sure that all fuses are of the proper rating. These old machines are often subjected to "mook" repairs along their life.
Rob/NYC
"If we believe absurdities, we shall commit atrocities" -- Voltaire