Seeburg DS sound change during play

Hi-
I have a new problem with my Seeburg DS 160. When playing a record- it will start out OK, but then it becomes muddy at the end. This happened after installed a new set of stylii from needlesforjukeboxes (quick shipping by the way!), and it starts out OK (not great) and ends up really bad. I should note that I do not have the ear speakers, so some of the muddiness may simply be a lack of tweeter.

Something tells me this is a mechanical, and not electronic issue because it happens with every record I play. I 'think' it might be as simple as adjusting the tone arm tension, but wanted to see if there are any suggestions before I mess with that and potentially make things worse.

I also installed a new drive bushing (or whatever the rubber drive shaft is called) to address a low rumble that comes on during play. It doesn't seem to have made much of a difference.


I looked through the troubleshooting manual, and didn't see this listed and haven't found anything on this site with a search.

Thanks,
RJ

It is mechanical. First test is to place the machine in play with no record. when the tonearm sets down (on no record) lift the arm away from where a record would be using the blunt end of a pen or similar object. list on the tonearm on the flat area just below the cart and see if you find noticeable resistance as you move the arm toward the trip of point.

You will find at least some resistance due to the trip switch and the arm itself may be unbalanced.

There is an adjustment on the arm assembly that pre-tensions the the trip switch to lower the load on the arm as it nears the trip spiral.

The adjustment is shown here:
http://s1192.photobucket.com/user/Rob-N ... rt=2&o=144
The screw in the middle of the elbowed lever is loosened and the lever is slid down to add more bias to teh spring and thus lessen the force on the tonearm/stylus. Lowering it too mush will cause the arm to trip off at any vibration.

The lateral balance is via a counterweight:

http://s1192.photobucket.com/user/Rob-N ... rt=2&o=143
This is a shot of the underside of the tonearm assembly. The weights here have been cut down to use the newer cart in the old cradle. The adjustable weight is the squared off one and it will still be round on yours. If adjustment is needed, place the assembly in play w/no record and reach under to slowly turn the weight so that the arm does not bias in, or outward with respect to the record grooves.

Tracking weight is adjusted with the two long springs at either side of the arm. I usually keep the ears all the way down which corresponds to approx 3 grams force.

Rob/NYC

Hi, after you have done what Rob advised also check for excessive end float on turntable drive shaft, and to much slop as I call it, on the turntable drive bushes, both theses things can give sound issues.

Rob, DJRIck,
Apologies for the belated reply but thank you! I've been traveling the past few days, but will follow through on your suggestions. Any opinions on the replacement needles vs. the 'originals'? I wonder if they are lighter, or if the needle doesn't stick out as far, hence the new problem with the bias??

THanks again- great resource here.

RJ

I wonder if they are lighter, or if the needle doesn't stick out as far, hence the new problem with the bias??

Just to be clear, the bias issue has nothing to do with tracking pressure. Bias here refers to the tendency of the arm to want to move laterally along the playing surface of the record -either toward the center or outward.
The trip switch does begins to load the arm toward the end of the playing grooves but the spring relieves most of that if adjusted properly.

Excessive tracking pressure could cause the stylus cantilever to collapse, however that would normally affect the whole playing surface.

Rob