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
Hello everyone,
I acquired a well-used 1800 last year for $15 (cartridge but no needle). I stripped it down, cleaned the old gunk off of all of the parts, gave it a regrease and put it back together, I also ordered a soundsmith replacement cartridge. All the functions seem to be working as intended, except for the antiskate. With it set at the MMC4 setting, every time I cue the tonearm, say for a track midway through the record, and then drop it, it jerks back to the beginning of the record. I've attached a video to show what I mean. I've experimented a little, and the only thing that seems to prevent it is if I remove the antiskate spring from the tonearm assembly entirely. It's possible I made a mistake reassembling the turntable, but after poring over my notes I'm fairly confident it's assembled correctly. Any ideas? Thanks,
Video: https://youtu.be/AeHoDWeo9yM
Geoff
Did you balance the tonearm and is the tracking force set correctly
Collecting Vintage B&O is not a hobby, its a lifestyle.
Yes - I've followed SoundSmith's instructions, with the balance set to 1.2g per the dial. The problem persists.
Does anyone else have any ideas? Thinking about the mechanism, it almost seems like there should be another spring pulling towards the center of the platter, so that the adjustable spring can be dialed in... Either way this one is stumping me, I just can't seem to figure out how the spring tension is kept light enough to prevent jerking the tonearm. Maybe I have the spring connected to the wrong location on the tonearm?
Hello all,
I disassembled the turntable again to give you all a clearer view of what I am working with. I've uploaded another video to make it easier to see, what you will see me do is demonstrate that the tonearm floats and is balanced at a setting of 0 on the dial, setting the tonearm to 1.2g or so, and then showing that the arm still wants to pull back against the outer stop. I also demonstrate that it is clearly the antiskate spring which is the culprit. Does anyone have any other suggestions for what I should do, short of removing the spring altogether? Thank you,
Video: https://youtu.be/rynOCBSSDdY
Bumping for visibility, any help?
I would try setting up the arm, both for tracking weight and the anti-skating bias, with a test record.
If the anti-skating bias adjustment is too powerful - if the spring is the wrong strength, for example - results from a test record will tell you and enable you to set the bias required.
With both Lenco and SME arms (though not with B&O turntables) using the 'string & weight' anti-skating bias, which should be more reproducible than a spring of unknown force, I often found the the setting indicated by a test record was different to the recommendation simply based on tracking weight and a graph, usually much less than expected.
If other members' experience differs, I am happy to be corrected.
Thanks for the suggestion Kimberly,
The spring is original to the turntable, and one of the few parts I didn't remove when I stripped the table to clean it, so I'm fairly sure it has the correct stiffness. It almost seems to me like there should be some force in the opposite direction that the spring will balance out - having the spring on with almost any amount of tension pulls the arm hard enough that it will skip on the first groove. I can also see it installed on photos of other peoples 1800's I can find online, so it's truly baffling. I'm half tempted to just remove it all together and go without.
Phoenix70:It almost seems to me like there should be some force in the opposite direction that the spring will balance out
What you're showing in your video is what *should* happen. It's the act of playing a record that creates the opposing force you speak of - namely skating error - the friction of the stylus inside the groove, which pulls the tone arm toward the center of the record. Without this opposing force, of course the applied antiskating force will push the tone arm toward the rest position. And btw, here (see on TOP) Soundsmith recommends 1.3 grams tracking force, which is what I'd set it at.
Thanks Bob. I actually did run it with a record last night, at the MM4 setting the arm skips on the lead in groove as it gets pulled back by the antiskate spring. Eventually I just kept dialing it down until it could track, but the spring is basically slack, the indicator for antiskate is off the charts. I can post a photo later tonight to explain what I mean if that wasn't clear.
Ok; might help since in the first video it's doing what it should.
Okay, here's an update:
https://youtu.be/Z2nxm1rZAoA
I set it for 1.3g of tracking force, and at the MM4 setting for antiskate, you can see the needle skipping the grooves. That said, once I turned off the video I was able to adjust the spring so that the player tracked, it's just pretty far off from where it I dicates it should be.
My 1800 was reacting in a manner very similar to your video. I discovered a small broken pivot "hinge" lying underneath the cueing base mechanism. (part was about 3x2 mm) Tonearm pivot pins are suspended by the hinge. The right side was broken and as a result the cueing base was skewed downward which moved the tonearm to the beginning of the record. I used an adhesive to reattach the part. Repair was difficult but successful.
EDGE Acoustics