I have recently been laid up with a duff knee cartilage. Bored out of my mind, I decided to scratch a very old itch. My late wife badgered me into selling my old hifi separates years ago (Yes, I know, I know! Give me a break). Over the last few weeks, I've scoured eBay and picked up a mint Sony STR-6055 receiver that I serviced and restored. This week, I got a Pioneer PL12D II turntable in fairly reasonable cosmetic condition.
The fitted cartridge, a Shure M75EJ Type 2, was, as I recall, a pretty respectable low end cartridge back then (mid 70s). I sourced a replacement stylus from a local branch of Maplin and set about breathing life into the turntable. Did the basic arm adjustments. Mmmm, those bearings feel a tad rattly, more on this later. The drive belt, that looks and feels new (ish) was good to go, so I fired her up.
Huuuummm! Oh. Dear.
Not an earth loop or bad wiring (I'm an audio technician). Must be motor vibration. I scoured the 'net and found you guys. This thread proved most invaluable.
I bought some 'AutoGlym' Rubber and Vinyl care solution from Halfords and soaked the motor support cushions.
This helped *a lot*, but the hum was still clearly audible. albeit much less loud.
I replaced the foam damping material inside the platter suspension springs and this lowered the hum still further. But it was still there. By now, you've pretty much discovered that I am like unto a dog with a big juicy bone about stuff. I have issues
There was mention in this thread of mousemat material coming into play. I use a 7/8" 'Qmax' punch to cut a number of pads from a sacrificial 1/4" thick mousemat that I inserted into the spring locating holes on the plinth to physically isolate the springs from the plinth ledges. Quieter still.
But. Still. There. Aaaargh!
I removed, cleaned and re-tensioned the tone arm bearings. Fiddly and not for the faint hearted but this was *not* going to beat me. This helped with isolating the tonearm and eliminated most of the tracking rattles I was hearing.
I removed, cleaned and lubricated the central spindle that was, as it turned out, drier than a kangaroo's dry bits. The bearing surfaces were still good. As witnessed by the time it took to get the air out from the cylinder meaning that bearing was still a good interference fit; the spindle took a long time to slide fully home. This augered well. At least the platter runs true.
I cleaned and lubricated the motor bearings with EP90 (Gear box oil) and... voila! Silence! Beautiful silence!
I'd almost forgotten just how good vinyl sounds.
Hello from a newbie and many thanks for pointing me in the right direction.
This turntable will do until I buy a modern replacement. Which may be a while since I restored this Pioneer. Clearly, it was popular back in the 70s for a good reason other than price