Am I Expecting Too Much from Jukebox Audio?

[Ron Rich]

Hi David,
I don't think you need to purchase a "New" cartridge--just "un-do" what you done !! (LOL). The needle point should be at a 45 degree angle to the record with ZERO deflection of the shank that holds the needle point. Check this with the turntable motor off, using a non-warped record, and a "Gen-u-whine" needle. As for needles--I don't believe needles4JBs, sells originals of anything--all are "generic" as far as I know. I don't know, if he sells springs and or wheels--look to suppliers listed in Europe for the spring, and there are several "re-surfacers" of wheels listed in our FAQs..
The motor felt pads are in the outer housings, pressing against the (brass) bearings, unless they changed the motors ?? (It's possible they changed the bearings to nylon, and dropped the felt pads ??) --look on the inside of both of them-- No, you want the felt wet--but you don't want enough oil there to be thrown around ! Ron Rich

[robnyc]

David, that is the worst example of dredging-bottoming I've ever seen in an arm that still played. The record is off-center, but the added friction is adding to the pitch problem.

Take a lok at the front of the stylus shroud. If Shure it will say-so. If generic it will be blank, Generic's are almost always a lot more floppy. You can use them in that arm but it must be modded to track at 3gm or less.

I do suggest reading this topic: jukeboxaddicts.proboards.com/thread/420/tone-arm-modification-rockola

In the meantime, make sure the tonearm spring is fully extended. The adjustable clip should be at the point closest to the cart. If you do the mod you'll remove that spring altogether and set tracking with the counterweight.

BTW: the machine looks really pristine. As someone who often seem jukes at their worst, it's nice to see a clean original.

RobNYC

[dscott77]

robnyc:

"worst example of dredging-bottoming I've ever seen" That bad? Yikes! I stand ashamed.

"The record is off-center..." Do you mean the actual disc or the platter's position on the turntable mech? If the latter, I honestly don't know what this means nor how to fix it. The mech sits where it sits because that's where it sounds best (i.e., no pitch fluctuation). However, perhaps after lightening the tonearm load, that will change. I dunno.

"... but the added friction is adding to the pitch problem." I immediately will remedy as per your suggestions and likely will order the tonearm kit referenced in the link.

"... the machine looks really pristine. As someone who often seem jukes at their worst, it's nice to see a clean original" Well, this makes me feel somewhat better! Previously, my only sin was to let it sit unplayed for too long. I really am trying to do right by this machine but the combination of limited availability of parts, woefully inadequate (for a newbie) original service manuals and my own lack of jukebox restoration/adjustment experience has been daunting.

None of my styli are "Shure." The recent ones came from John Durfee. At least the cartridge is a Shure M44MR but I have yet to find specific instructions on how it should be installed in the tonearm.

Ron Rich:

I'll continue to search for an original stylus and, in the meantime, attempt to do what you and robnyc have suggested regarding tonearm weight and stylus angle.

Regarding motor lubrication, I've given up trying to locate "felts." I just don't think they're in the motors that I have. Before reassembling, I did use a tiny amount of 3-in-1 motor oil on the spindle bottom that fits inside the wire-wrapped sections as well as a drop into the top ring around the spindle as seen from the top of the reassembled motor. I admit I know next to nothing about electric motors but can only assume that if mine have bearings, the are very small and reside in that ring.

I'm considering having one of the two idler wheels I own rebuilt. Both are used. Should the rubber rim be rock-hard or have some give? Also, what should I be cleaning it with? Alcohol?

[Ron Rich]

Hi David,
Shoot a photo of the inside of that motor's housings---
The cart should fit into the tone arm as I described above (twice-I think)--"UN-bent"
Idler wheels should be soft--ish--not hard ! Al-kee-haul works on them as well as glycerine, and/or, a plastic safe-safety solvent. Ron Rich

[robnyc]

David, the record is off center due to either the hole being slightly too large, or the turntable pilot slightly small.

You will hear this a bit when you are used to digital audio but there is also a drag from the arm being too heavy. I also detected slight scraping sound just before thew music starts. If so it may be the bottom of the cart hitting the record.

Since it seems you have a generic styli the tonearm tracking weight (called vertical tracking force VTF) becomes more critical.

The mounting looks OK, did you install that cart?

RobNYC

[dscott77]

A clue as to my tonearm weight problem: The digital stylus pressure device I have calibrates to zero, reads 5 grams when I place its five grams weight on the scale but reads "full" when measuring the tonearm at the point of the stylus. The scale's instructions do not say what "full" means but I'm assuming it's wieghing more than 5 grams -- which might explain why this is the "worst example of dredging-bottoming I've ever seen"? Worse, I get the "full" reading no matter where I've placed the tonearm spring and even if I remove the spring entirely.

Ron: my idler wheels are pretty hard so maybe I need a new or rebuilt one.

Also, you did say "un-bent" twice but, sorry, I don't know what "un-bent" means in the context of the tonearm. I simply pushed it into the tonearm as best I could. Believe me, I would like to correct its position if I just knew how it's supposed to fit differently from the way I have it. Honest!

robnyc: Early on, when repeatedly trying to insert a styli, I had to remove the cartridge to successfully slide the stylus in place. Afterward, I re-mounted the cartridge. Maybe it's in there wrong but, as noted earlier,

[dscott77]

P.S. The scale I'm using seems to accurately measure a variety of small items and never says "full."

[Ron Rich]

Hi David,
I read the early post as if you had "bent" the mounting on that cartridge. If it is original, and you replaced it in the original mounts, with out "adjustments", it should be OK--I still would purchase a new spring, as "people" have a tendency to "mess with" them. As for your gram meter ?? who knows ?? It would seem to me to be very odd that it still reads "full" with the spring off the tone arm ? (How much deflection, do you see in the needle support ?) Ron Rich

[dscott77]

If by deflection you mean how much variation from the 45 degree angle, I'd say the weight totally smushes the stylus down toward the record's surface.

Here's a link -- www.dropbox.com/s/2rzkpbl0gh4aft0/IMG_0966.jpg?dl=0 -- to a photo of the tonearm-mounted cartridge. Getting a good shot of the deflection when the cart is atop a record is nearly impossible. There just isn't much daylight at all.

In the section of my service manual labeled "Tone Arm Adjustments," the only thing I see as changing the weight of the tonearm pertains to the spring adjustment. So far, I don't seem to be able to affect that, even with the spring detached. And yet, records get selected, the needle sets down in the right spot and rises appropriately at the end so that the disc can be replaced in the magazine. To your point, though, it surely seems the tonearm and stylus ride too close to the record.

[dscott77]

It's a mystery but I've tried playing several discs with the spring the tonearm lug closest to the cartridge and the one at the other end. Shining a strong light reveals that there is some deflection but it's not as severe as it seemed earlier. Also, there was none of the sound of the cart touching or scraping the record that I've been hearing. The pitch fluctuation remains much improved if not pretty much gone. I have done nothing different and made no adjustments except for changing the position of the spring on the lugs.

I gently compared the tension of the current stylus with the others that I have and they all seem the same. I am reluctant to try to bend one down a little since I found out the hard way a while back that can lead to a break, not to mention heartbreak.

I can't explain why my digital stylus pressure scale happily produces weight numbers for a variety of small objects but reads "full" no matter what I do to the tonearm. The only way I know of to check this is to buy another scale.

I will obtain a new idler wheel and spring and maybe one of those tonearm kits. I'll also cautiously lubricate spots that I'm reasonably certain are appropriate but beyond that, my well-meaning but inexperienced efforts may be counterproductive.

You and robnyc have been most generous and patient and I appreciate it. At the end of the day, there is only so much you can do long-distance. The retired repair buy I've mentioned several times hung with me over many weeks and I'm certain he grew weary of the back-and-forth. You guys and he are to be commended.

[robnyc]

David the reason your scale shows "full" -as in full scale is the same reason you have all that crud on the bottom of your cart; the weight is way to heavy. BTW" A older penny made before the early 80's weighs 3 grams. A later one is about 2-1/2 gm.

In your pic I don't see the spring at all. It should be stretched from the two farthest points for lightest weight. That being the stationary anchor point at rear and the steps up near the cart.

RobNYC

[dscott77]

The spring had been unhooked in that picture. After the shot, I put it back onto the nearest lug toward the stylus end of the tonearm. According to my service manual, that should provide the lightest weight. But as noted earlier, the scale reads "full" even when the spring is not attached. I check the scale batteries and they both read 1.49 to 1.51. I absolutely understand that the tonearm weight is too heavy and am desperately trying to lighten it but I can't seem to do it.

As for the scale, I just weighed a 1984 penny and it reads 2.51 grams. Although I believe the scale is operating properly, I've ordered a $25 one that has a range from 001g to 10g. Surely it will tell me how much over five grams the tonearm weighs. All I can do at this point is put back the original tonearm spring and see what happens. The one on there now was sent to me as "new" by my repairman contact but maybe it is the problem.

I've been playing lots of records this afternoon and evening. Some sound great (such as high energy tunes like "Abracadabra" and "Magic Carpet Ride"). Some sound awful (like the slow, note-sustaining "Ten Commandments of Love."). Some sound just OK but certainly acceptable. In some cases, the records themselves might be lousy pressings. But I know the tonearm weight is exacerbating my woes.

If that extra (older) spring set at the lightest lug still makes my scale say "full," I'll just have to wait until the scale with a range up to 10 grams arrives in hopes of really finding out how much the dang thing weighs. If it's well in excess of five grams, the only apparent recourse is to try to track down another tonearm spring. I know of no other way to lighten the load.

I've peered at the tonearm thinking that I could find something bent or funky-looking that might be causing the extra weight. So far, nada. Very, very discouraging.

[dscott77]

Whoa! A genuine breakthrough! I replaced the old spring, then tried the scale. This time, for the first time, it did not say "full." Rather, it read "3.41."There also is much more daylight between the bottom of the cartridge and the disc. Another first.

Holy cats, I am ecstatic! Between now and tomorrow, I'll play more discs but the few I've already tried sound good.Maybe I'll put a hold on that second scale!

[dscott77]

One more thing: When installing the old spring, I looked closely at the drawing in the service manual. I think the straight portion of the spring MUST border the Inner bend of the tonearm and not the outer bend. I confess that I had the replacement positioned opposite of the drawing -- for no good reason other than not knowing that it would make a difference. Now, though, it looks like that doing it the "wrong" way must directly affect the tension and skews the weight of the arm. I've played several more records and they sound terrific but I before I declare victory, I will play many more tomorrow. Tonight I've gotta give my spouse a break from all this!

[dscott77]

Postscript: I finally found time to order, receive and install the nicemite.com tonearm counterweight modification referenced on this site. According to my inexpensive scale, the weight now is 1.2 grams but whatever it is, the wow and flutter issue about which I've whined is now minimal. Apparently the spring just couldn't do the job with the replacement cartridges available for this jukebox. Also, though this forum was too polite to say so, my Rock-Ola Model 1000-3 is not in the same class as true vintage machines and its manufacture perhaps left much to be desired. Consequently my expectations are more realistic. Thanks to Ron Rich and robnyc for all of the help. Over and out.