'What's this knob for?' and other Q's about my turntable

[Blueberry]

Trying to wring more performance from my 1970s era Philips turntable. I've never spent too much time adjusting things because I don't know what I'm doing. Everything sounds great on the first band or two. I understand some degradation in sound quality is normal as you move inward, but mine seems to fall pretty quickly. Have an Ortofon Super OM20 cartridge, which I pretty much slapped on several years ago. Probably due for a replacement stylus.

Can you tell from these photos if I'm doing anything terribly wrong? Do you have any answers to these questions? Any recommendations on how to best adjust things would be most appreciated!

 

[Herandu]

What you got there is quite a bit of a tweakaholic turntable. The knob you point to is a control to either sets the anti-skate level of the two most common form of stylus tip design, OR it sets the tracking weight.
Has the counter weight on the back got a metal disk with numbers on it going from1 to 3? If it hasn't, then that dial you point to is the tracking weight adjustment.
It is the 1st time I have ever seen one like that by the way, and might have been a new invention that never gained popularity.

If you undo the spring loaded screw a bit, can the arm height then be moved slightly up or down? If it can, then it is a VTA adjuster.


Your tracking weight is set too high. The stylus cantilever has sunk right into the cartridge body. The reason the sound gets worse as the record goes towards the centre is because of the wrong tracking weight and those dust particles stuck underneath the cartridge body just behind the stylus tip.
Judging from the various angles, the arm height also needs adjusting.

Assuming you are as much out of your depth as you mention, the first thing is to find out if the arm height can be adjusted via that spring loaded screw. If it can, I would raise the arm by about 5mm.
Next is to turn that dial marked spherical and set it to 0.
Next is to adjust the arm weight at the back until the arm is level and the stylus is not touching the record. Now look on the weight for some numbers. If there are numbers, rotate the dial those numbers are imprinted with till the 0 is the one at the top. Now rotate the weight at the back till the dial now shows 1.5 at the top.
If there are no numbers on a dial around the arm weight, rotate the dial marked spherical till it points to 1.5.

Wipe the dust from underneath the cartridge.

Now play a record and let me know if I am on the right track.

 

[Kees]

And put the shell straight on the arm (last pic).

 

[Kees]

The eliptical/spheriacal dial is the anti skating
Set it to the same value as you tracking force 1.3 g is ok for om20, so this setting seems to be correct on your pic.
You use the brown scale if you have an eliptical stylus and the other scale if you have an oval stylus tip in your cartridge. The om20 usually has an eliptical stylus.

 

[Blueberry]

Thank you for the tips. And thanks for clearing up the anti-skate adjuster. Herandu, thanks especially for the direction. I wasn't able to adjust the arm height with that spring-loaded screw. Far as I can tell, it affects the distance the arm travels when I press "Start."

I didn't realize the cantilever on the stylus had sunk, and I imagine it isn't doing my records any favors. So I've stopped using the TT until I get a replacement stylus.

 

[juniperlater]

What a great turntable! I have had a lot of its little siblings - 222, 212, 312, etc. This is a fantastic find!