Seeburg V200 needle jumping in on B side

[jeffinmn]

I have a Seeburg V200 that I've had since about 2002. I have the manuals and replaced the caps in the amp and selection receiver. It works well except that when playing the B side of records, when the arm is released, it jerks in a few grooves. When playing the A side the arm lands as it should and lands properly and smoothly on the record. I've gone through the adjustments and they all seem to be fine. I'd appreciate it if someone here could suggest what to look at to resolve this problem. 

[Ron Rich]

Most likely, if nothings been changed, or incorrectly "adjusted" since the mech. worked correctly, it's either lack of proper lubrication, or the tone arm wire has become stiff--

[jeffinmn]

Hi Ron,
I've checked the tone arm wiring and lubricated the mechanism. The tone arm wiring is not stiff at all and is very flexible, like kite string. It plays the A side of records perfectly. I'm wondering if there are some adjustments I should recheck. I'd appreciate it if you can recommend what adjustments to check that, if wrong, could cause the arm to jump in when starting to play the B side of records. The jump happens right at the end of the cycle.

[Ron Rich]

There are only a few mechanical things that can affect this, that I can think of--tone arm wire ("Kite string"--I dono--depends on how large it is ?) which should be 30 gauge, twisted pair, the type/weight of the cartridge (which one is in use/which needles ?), spring pressure, tone arm balance---and the cam shaft detent notch/roller.

[robnyc]

Jeff, Ron has touched on one of the items I was preparing to suggest, but lets start with basics.

-Check for balance. Select a "B" side with no record. As the arm falls toward the record and is released it should not jump inward. After it settles pull the pickup back away from the record position, release it and check again for any serious bias.

After this is checked take a look at this pic: www.flickr.com/photos/90641375@N06/39675424492/in/dateposted-public/

The upper arrow is the tip of the keeper that holds the arm at the reset position till just before it is released to follow the grooves. Loosening the collar bolt ( lower arrow)and backing the grub screw out till the keeper just barely touches the tip of the keeper blade. This will prevent the slight jolt that can happen when the keeper is held too tightly and the assembly "snaps" a bit at release. Remember to re-tighten collar bolt.

The next one will not meet with Ron's approval, but it is SOP on all my machines: Remove the damping. I have found that if the damping is engaged the arm may not be totally down in time to follow the record. There is another collar bolt that locks yet another grub screw that keeps the damping cylinder from moving. It is accessed with a tiny wrench to loosen the bolt and a small screwdriver through one of the holes on the front of the cradle. I loosen the bolt just enough to allow me to back the screw out just to the point where the damping has no effect and the arm is free. Re-tighten the bolt.

Check the tonearm setback. The arm should -only- go far enough back (toward the mech cover on B-side position)so that the stylus will be clear of a rising record. If too far back it may again, not be fully in contact with the record when the keeper releases it.

Normally, these should never need attention, but with used and tinkered machines -who knows what was done. This fine tuning is a one-time operation.

I've had this problem on several machines when they were dumped on me by people on Tenth Ave -these are the methods that always fix it.

RobNYC

[jeffinmn]

Rob NYC,
Thanks for these suggestions, they are exactly what I am looking for. The arm has a Pickering 345-03D cartridge on it and I added 7 grams to the top of the cartridge in the form of a shaped blob of solder that weighs 7 grams. This was suggested in a book of service suggestions. I don't have the book with me as I am out of town. After adding this weight the arm is now in balance and doesn't float in or out.

I will check the keeper and adjust it as you said and also check the other things you indicate. I'm relieved to read that you've had these problems and were able to find a solution to them.

Ron, by comparing it to kite string I'm just saying that it's very limp. If I was going to replace the tone arm wiring what tone arm wiring would I replace it with? Do you have a recommend place and part number to purchase tone arm wiring from? 

[Ron Rich]

As Rob suggested, he and I diss-agree on the damping fluid-- If I were to guess, I would guess I have restored over 10k Seeburg mechs in the last 50 years. I have never run into one that worked correctly without the fluid--in fact I have replaced many a tone arm because of no fluid left in them. Without the fluid, the tone arm "bounces" into the records, and destroys needles. Which needles are you using--what's the spring pressure adjusted to ? Tone arm wire used in mono phono's was 32 gage. The tone arm lock pin should not need adjusting -- check to be sure it's not been bent--see the service manual. If using a 345 cartridge, did you trim the B side needle brush ? Ron Rich








--Ron Rich

[jeffinmn]

Ron I understand what you are saying about dampening. It will be the last thing I try, if necessary. I am out of town until early February so I won't get to try these suggestions till I get home.

Regarding the tone arm lock pin, is this the long pin that you measure to have 1/32 to 1/16 clearance? When I was checking the various adjustments and measurements there was a difference in distance between having the arm on the right side versus the left side (Side A versus Side B). I don't remember what the part is called and I did not bring the service manual with me. The left side gap was correct but the right side was about 3/16. I was thinking about bending the part which it said to do. I think it said to straighten it. But I am concerned that I could break it off. What are your thoughts on this?

[Ron Rich]

Jeff,
I have been sucessful in bending many, without breaking any off--yet !! lol!

[jeffinmn]

I went through the various steps recommended here and found the problem was largely resolved by reducing the distance of the arm from the record on the B side so that when the arm is lowered it has more of a chance to land in a groove and not jump in. I did not change the dampening. I played about 20 B sides of records tonight and though it jumped in just a bit on a few of them, it did not jump past the beginning of the music.

Thank you both for your time posting here and the valuable information you provide.

[jeffinmn]

So I'm finding that the jumping in on the B side problem still occurs fairly often. I've posted a video on youtube of this happening and would appreciate any suggestions for fixing it. I don't understand why the arm lands properly on the A side to the point that one can hear the stylus getting grabbed by the lead in groove but on the B side the arm jumps in as shown in the video. 

[Ron Rich]

Watch the main cam shaft--is tha "jumping" at the same time ? Ron Rich

[jeffinmn]

The tone arm jumps at the point it is released, when it lands on the record. The Cam Assembly, which I see on page 21 of the manual, makes one full revolution each time a record is loaded. It is always at the same place when the stylus lands on the record and the tone arm is released. Perhaps I am misunderstanding. The cam assembly I am referring to is parallel to the floor.

[Ron Rich]

Jeff,
The main cam assembly runs thru the center of that casting--you can easily view iit's action by watching the brake cam on the very left-outside/under the clamp arm---Ron Rich

[100j]

After some considerations and experiments I solved the "mystery" of skipping on B-sides only, which is reported at several places in online forums and literature:

The force that often pulls the tonearm inward on earlier Seeburg machines on the B-sides at the starting groove and only on newer (stereo) records is nothing else than the physically caused "skating".
I searched for the cause of the occurrence exclusively on the right side of the record and - assuming all adjustments mentioned above are done properly - finally found the reason in the construction of the vertical Seeburg drive itself. Strictly speaking, this construction with reversal of the running direction is not optimal, because skating only occurs under certain conditions or is caused and influenced in extent by the following factors:

- tone arm geometry
- needle pressure (the stronger, the more skating force)
- needle cut
- groove depth (of the record)

For relatively early Mono Seeburg machines, the tonearm geometry is decisive: Due to the arrangement of the tonearm at the same place for A and B sides, a playing against the logical direction as well as the very close position of the needle to the center of the record for A sides, skating can hardly occur in this playing position. The situation is different with B-sides, however, because the needle is pulled towards the center of the record due to the greater distance from the center axis and the different, "correct" direction of travel - the classic skating effect.

Of course, the question now arises as to why this has never been an uncontrollable problem with these machines. My observation is that skating is virtually non-existent with old mono records, despite relatively high contact pressure, because of their greater groove depth.
Later, with more modern stereo records and pickups, the tracking pressure was significantly lowered, thus reducing the skating force. In addition, the grind of the scanning needle used has further influence.

In the case of my 1955 „J“ box (equipped with the red stereo system and adapter), I was finally able to eliminate the effect by reducing the tracking force to 4.5p using the original tonearm springs.

Stefan