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Tracking Force Gradually Increasing On Its Own

mwaehner

mwaehner

New Member
Hello all,

I've been searching around and can't find anyone going through this, so either this is really weird or I just don't know what to search for.

I've got a Pro-Ject Debut III that has been serving me well for about six years. In the last few months it has been doing this bizarre thing. Its vertical tracking force has been increasing, seemingly of its own volition. I first noticed an issue a couple of months ago when I was suddenly getting way worse inner groove distortion even though the stylus on my Audio-Technica AT120ET was pretty fresh. It weighed in then about .5 grams too heavy (I tend to set it up about .2 grams under the maximum). I reset it, and now I've been checking it every two days or so. It usually moves up by about .2 grams in that time, and I roll it back again.

I tried tightening the headshell screws, which I guessed could cause something like that, but it hasn't had any effect. I feel like the moveable dial on the counterweight remains accurate, suggesting that the counterweight is getting moved somehow. But I've studied my motions when using it, and I can't imagine that I'm turning it on accident. The dust cover is always down when it's not in use, and my cat, while malicious, is not that clever. I am not ruling out ghosts or bizarrely consistent sleepwalking.

Anyone heard of this? Any theories? Help me, o fount of turntable wisdom!
 
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Low pressure zone lately? Tornadoes in the forecast?

Otherwise that's a new one on me.
 
mwaehner said:
Hello all,

I've been searching around and can't find anyone going through this, so either this is really weird or I just don't know what to search for.

I've got a Pro-Ject Debut III that has been serving me well for about six years. In the last few months it has been doing this bizarre thing. Its vertical tracking force has been increasing, seemingly of its own volition. I first noticed an issue a couple of months ago when I was suddenly getting way worse inner groove distortion even though the stylus on my Audio-Technica AT120ET was pretty fresh. It weighed in then about .5 grams too heavy (I tend to set it up about .2 grams under the maximum). I reset it, and now I've been checking it every two days or so. It usually moves up by about .2 grams in that time, and I roll it back again.

I tried tightening the headshell screws, which I guessed could cause something like that, but it hasn't had any effect. I feel like the moveable dial on the counterweight remains accurate, suggesting that the counterweight is getting moved somehow. But I've studied my motions when using it, and I can't imagine that I'm turning it on accident. The dust cover is always down when it's not in use, and my cat, while malicious, is not that clever. I am not ruling out ghosts or bizarrely consistent sleepwalking.

Anyone heard of this? Any theories? Help me, o fount of turntable wisdom!
Click to expand...
What are you using to measure the vertical tracking force? What is your procedure?
 
It doesn't explain what you heard but I'd get another scale to verify the VTF is in fact increasing. Is it possible someone else dusts your turntable?
 
MRL_Audio said:
Are you playing anything from Barry Manilow? Pro-Ject may be rebelling...
Click to expand...

Hey, hey now... let's leave my man Barry out of this!

As far as tracking force changing on its own, it may just be inconsistencies in your digital scale. My digital scale is one of those $20 deals from the net - it works well enough, but I notice sometimes it fluctuates a little though I've moved absolutely nothing on the tonearm. I just take a few readings and mentally average the results.

Test the scale with pennies. 2 fresh new US pennies should weigh 5 grams give or take a few hundredths.

For the hell of it, you could take a couple readings across the platter -starting at the lead-in and ending at the runout. See if the bearings in the pivot are consistently allowing the application of the same weight across the record.
 
Hi,

I'm intrigued by the logistics of this. Quite obviously resetting 0.1g per day
by reduction will eventually lead to the counterweight falling off the end
of the stub, which is just ridiculous, it is never going to happen.

The arm presumably balances level with a counterweight setting,
where you set the dial to zero. Your saying the zero point is moving ?
How are you judging the increase in tracking weight ?
How are you setting your apparent tracking weight ?

rgds, sreten.
 
Last edited:
mwaehner said:
Hello all,

I've been searching around and can't find anyone going through this, so either this is really weird or I just don't know what to search for.

I've got a Pro-Ject Debut III that has been serving me well for about six years. In the last few months it has been doing this bizarre thing. Its vertical tracking force has been increasing, seemingly of its own volition. I first noticed an issue a couple of months ago when I was suddenly getting way worse inner groove distortion even though the stylus on my Audio-Technica AT120ET was pretty fresh. It weighed in then about .5 grams too heavy (I tend to set it up about .2 grams under the maximum). I reset it, and now I've been checking it every two days or so. It usually moves up by about .2 grams in that time, and I roll it back again.

I tried tightening the headshell screws, which I guessed could cause something like that, but it hasn't had any effect. I feel like the moveable dial on the counterweight remains accurate, suggesting that the counterweight is getting moved somehow. But I've studied my motions when using it, and I can't imagine that I'm turning it on accident. The dust cover is always down when it's not in use, and my cat, while malicious, is not that clever. I am not ruling out ghosts or bizarrely consistent sleepwalking.

Anyone heard of this? Any theories? Help me, o fount of turntable wisdom!
Click to expand...
It could be that the stem that the counterweight is mounted on is loose and is slowly moving forward.
 
mwaehner said:
Hello all,

I've been searching around and can't find anyone going through this, so either this is really weird or I just don't know what to search for.

I've got a Pro-Ject Debut III that has been serving me well for about six years. In the last few months it has been doing this bizarre thing. Its vertical tracking force has been increasing, seemingly of its own volition. I first noticed an issue a couple of months ago when I was suddenly getting way worse inner groove distortion even though the stylus on my Audio-Technica AT120ET was pretty fresh. It weighed in then about .5 grams too heavy (I tend to set it up about .2 grams under the maximum). I reset it, and now I've been checking it every two days or so. It usually moves up by about .2 grams in that time, and I roll it back again.

I tried tightening the headshell screws, which I guessed could cause something like that, but it hasn't had any effect. I feel like the moveable dial on the counterweight remains accurate, suggesting that the counterweight is getting moved somehow. But I've studied my motions when using it, and I can't imagine that I'm turning it on accident. The dust cover is always down when it's not in use, and my cat, while malicious, is not that clever. I am not ruling out ghosts or bizarrely consistent sleepwalking.

Anyone heard of this? Any theories? Help me, o fount of turntable wisdom!
Click to expand...
Sticky tonearm bearings is problem
JJ
 
I took a week off from the turntable (it wasn't a great week) to gather data by measuring the tracking force every day, then today every hour. Without boring you with the details, I tried lots of different things before I figured out the problem, and it was so simple I can't believe I ever figured it out.
The weight was too far back on the arm, so the dust cover was bumping against the weight every time I closed it. What I mistook for a gradual increase was actually a sudden increase to 1.9 grams every time I closed the lid with the tonearm in the resting position.
So I guess my Audio Technica 120 is just a heavier cartridge than the Pro-Ject Debut III was designed to use? Seems crazy, since it's only 1.5 grams heavier than the stock Ortofon OM 5e. I was looking at replacing it next time the stylus wears out anyway, so I guess I'll go lighter.
In the meantime, I need to add some mass to my counterweight so it doesn't have to go so far back to counterbalance the cartridge. Maybe just a washer and some blu tack, and a whole lot of trial and error. I'll try it out and report back. Thanks for your ideas!
 
mwaehner said:
I took a week off from the turntable (it wasn't a great week) to gather data by measuring the tracking force every day, then today every hour. Without boring you with the details, I tried lots of different things before I figured out the problem, and it was so simple I can't believe I ever figured it out.
The weight was too far back on the arm, so the dust cover was bumping against the weight every time I closed it. What I mistook for a gradual increase was actually a sudden increase to 1.9 grams every time I closed the lid with the tonearm in the resting position.
So I guess my Audio Technica 120 is just a heavier cartridge than the Pro-Ject Debut III was designed to use? Seems crazy, since it's only 1.5 grams heavier than the stock Ortofon OM 5e. I was looking at replacing it next time the stylus wears out anyway, so I guess I'll go lighter.
In the meantime, I need to add some mass to my counterweight so it doesn't have to go so far back to counterbalance the cartridge. Maybe just a washer and some blu tack, and a whole lot of trial and error. I'll try it out and report back. Thanks for your ideas!
Click to expand...

Counter weight interacting with the dust cover. I've done that but it would cause the record to skip with the linear tracking tone arm and the dust cover closed.
 
No good if cover hits counterweight no matter how far back if it is not falling off anywhere on stub cover should fit properly if design thoughtful
May move arm a bit and add some mass to weight as you mention
JJ
 
JimmyEJames said:
No good if cover hits counterweight no matter how far back if it is not falling off anywhere on stub cover should fit properly if design thoughtful
JJ
Click to expand...
Indeed. In the six years I've had this Pro-Ject I've mostly been very happy with its design; this is one of my few times to be disappointed.

But I sticky-tacked a penny to the back of the counterweight, and it's all working perfectly now. Mystery solved.
 
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