ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
I have an RX2 and the tonearm sits too low so when I hit play it bumps the edge of the record when moving over to start and when the record is over it might scratch is way over the record to the rest position. I have looked at the service manual and found where the adjustment screw should be. It is missing on mine. Does anyone know the exact size of the screw. It doesn't seem to say in the service manual. I am also concerned that the threaded hole is stripped on mine. I have attached a picture of the hole (as best as I could get to it).
I'd listen to the advice of other forum members who have been doing this longer than I have over mine, but, it sounds to me like your tonearm needs to be re-balanced. There is a procedure for doing that in the user manual. The user manual and service manuals are available for download to members at a Silver or Gold level.
Edited To Add:
Sorry, I thought I should clarify a few things here. The user manual's procedure to balance the tonearm doesn't mention any threaded screws. Essentially, you adjust the counterweight to make the arm float, adjust the calibrated scale to point to 0 grams, then adjust the counterweight to the desired stylus pressure.
It seems to me if the arm or stylus is hitting the record on its way over and dragging on its way back, that the tonearm is out of balance and is pushing too far forward. I may be mistaken here, and other forum members can feel free to correct me. But this is the basis of my reply and recommendation.
I wish that it was as easy as a rebalance. The counterweight would have to be at 2.00+ to keep the stylus from hitting the disk. And then the back of the counterweight scrapes against the dust cover hinge and the arm skates across the disk. I found the problem - tone arm height adjustment. What I don't have is the screw there to make the adjustment. I showed a picture of the hole where the screw should be. It looks to me to be stripped but nonetheless I'd like to know what size (metric or SAE) screw should be in there to make the adjustment. I can try to buy a screw and fit it in somehow (without dropping it into the 'abyss' where I would need to take the whole top off to fish it out.
Does anyone know the specs on that screw?
The pic shows an eccentric, there is no screw there as far as I remember, this eccentric is part of the height adjustment, follow the procedure described in the repair manual (available for silver and gold members)
Collecting Vintage B&O is not a hobby, its a lifestyle.
My bet is that the lift/lowering mech has broken at the back of the tonearm below decks.
Martin
Replying to Søren MexicoThe service manual actually states:
PICK-UP HEIGHT
Turn the eccentric K clockwise until it stops. Set the counterbalance weight.... Take the pick-up arm in over the innermost elevated section on the platter.... ADJUST THE SCREW L until the distance between the pick-up stylus and the platter is 9mm.
The eccentric K is behind the pivot. I did that step as well as the following regarding the cam wheel 1609.
Unfortunately the SCREW L is missing as I showed in my photo. So I ask again if anyone knows the size of the screw so that I may buy one and try to replace it into the open hole, hoping that it it isn't stripped.
Martin-
It does lower and raise but it lowers TOO FAR and thusly hits the side of the record. I just need to adjust the PICK-UP HEIGHT as described in the service manual. If I can get the proper size of the missing screw L then I will try to replace it.
thanks so far to everyone who are trying to help.
I looked at the image that you sent to me via the weblink. I don't believe that is it because mine doesn't have a large arm anywhere near the pick-up arm. If you look at my original posting photograph you'll see the hole that is missing the adjustment screw, which is in front of the pivot. The eccentric K is behind the pivot.
Measure the hole with a caliper, all B&O screws are metric or special made, adjustment screw around the arm are often M3 if the threads are damaged I would drill up to 3.5 mm and cut new threads M4, I think I have a RX2 somewhere, will try to find it and check later today
Didnt find a RX2 but a RX with the same arm as yours, will com back with pics, there is no screw in that hole
Here goes, the hole, NO screw. This arm is from a RX and NOT RX2 so be careful
Eccentric
Red arrow hole, Blue arrow tap, Green arrow L screw
The tap blue arrow goes there, the shaft Green arrow goes down to the lift lever
I appreciate the photos but I don't understand what the blue arrow "tap" refers to, nor how the green arrow item fits into it all. As the manual shows and says there is a screw in front of the pivot to turn to adjust the height. All I see is a hole.
Or is the adjustment screw the one shown by the green arrow in your third image??
I'm done with it. This was an RX2 I just bought on eBay listed as "working with MMC3 cartridge" but it wasn't so. Th cartridge that came with it was in pieces and an MMC4. The pick-up arm was bent at the back before the counterweight and the height adjustment made no difference so I am returning it.
The screw I am guessing was the Allen head screw on the post in front of the pivot but neither direction changed the height as the arm never dropped at all after moving over the record. So there were bigger issues.
Thanks for everyone's help with this. Much appreciated!
ganzo: I appreciate the photos but I don't understand what the blue arrow "tap" refers to, nor how the green arrow item fits into it all. As the manual shows and says there is a screw in front of the pivot to turn to adjust the height. All I see is a hole. Or is the adjustment screw the one shown by the green arrow in your third image??
The "tap" or shaft rest on the plate in pic 4, this plate lifts the whole arm support up and down, so at some point the lift mechanism was changed and the L screw moved to just under the tonearm (I wrote K screw now edited), the manuals at times are not up to date with all production changes