Rockola Tone Arm Counterweight

Hi Folks,

Thought I'd share what I've done to my 442s tonearm. I decided to add a tonearm counterweight to my Rockola 442 - as per Rob-NYC's suggestion (thanks once again!). I would have waited longer to do this but after using a stylus pressure gauge I found that even on the lightest setting, it was exerting more than 5g! Im no record snob and I believe records, even valuable ones are there to be enjoyed, but I'd like to be as kind to them as I can - within reason!

So initially my tonearm looked like this, it had am improvised and terrible cartridge lead consisting of some wires and loosely crimped cartridge tags, the arm was also dirty with residue from what I assume is glue from adhesvive tape:



I removed the tonearm and using a titanium drill bit, I drilled a 5mm hole in the back. I tried to keep the shavings away from the bearings, but some did fall below and stick to oil. I was sure to clear this off before reinstallation:



I put a 1 and a 1/2 inch machine screw through the back and used a washer and nut to secure it. As advised I used some washers to build up enough weight and after checking the gauge got it tracking at 3g.



I've now replaced the cartridge lead with a genuine rockola lead, and also cleaned up the arm. I will at some stage touch up the chipped paint:




Today I got the lighter tracking shure M44-7 stylus and now have it tracking at 2g

The only outstanding issue however is the needle bounces ever so slightly when setting down on the record, it did this with the other stylus too...I'll have a go at tweaking the set down position. At the moment I wonder if the arm is starting off too high when it drops down, will need to make a vid of that

My 442 is moving on in leaps and bounds. I've been cleaning it up and its amazing just how much filth is on this thing! It also smells like an old garage, so I hope the cleaning will get it smelling fresh!

Adam

Adam, as I said privately that is a good looking job. Why R-O didn't go with a simple counterweight instead of that goofy spring is beyond good reason. They would have had one of the best arms in the industry.

Some possible reasons for the bounce problem:

1) Does the changer motor slow down a second or so before set down? It is supposed to.

2) If the changer motor is too tight with it's gears the whole mech will bounce due to backlash as the pinion and gears turn.

3) The stylus need only just clear the gripper by a small fraction of an inch.

4) Check the action of the cam and it's follower to see if it is smooth on the profile that lifts the tonearm.

I never had a problem that wasn't solved by one of these checks. However as a last resort, if the mech continues to bounce too much you might stuff the mech mounting springs with foam pads to dampen their action. I've never had to do this, but it is an idea if all else fails.

Rob

I just adjusted the gripper clearance, it was WAY too high. Some moron had also bent the stylus brush upwards to accommodate this goofy setting. After substantially dropping it, yet with ample clearance of the gripper it now sets down just fine. I'm actually amazed how well this mod works, a jukebox tracking great at 2g, who'd have thought it!! I think this should be done to every Rockola, and with the M44-7 cart looking identical to the M44MR, you can get a nice sounding cart that looks authentic and is gentle on records

Psychman wrote:I just adjusted the gripper clearance, it was WAY too high. Some moron had also bent the stylus brush upwards to accommodate this goofy setting. After substantially dropping it, yet with ample clearance of the gripper it now sets down just fine. I'm actually amazed how well this mod works, a jukebox tracking great at 2g, who'd have thought it!! I think this should be done to every Rockola, and with the M44-7 cart looking identical to the M44MR, you can get a nice sounding cart that looks authentic and is gentle on records

While all of this is commendable, it still IS a jukebox, not a high-fidelity turntable.
Going so light (2G) is kind of silly for such a machine, a sort of overkill.
Tracking 5 grams with an N75C stylus would be a much better choice in my opinion, and quite gentle enough for 45's.
The added benefit to the slightly higher tracking force would require moving the added counterweight closer to the vertical arm pivot, lowering its effective mass at the stylus tip, and allowing it to negotiate warps better. (think overall stability)

Remember, lighter is NOT always better, particularly in this case, so no need to go nuts with it.

I think you'd be surprised how well this works, it's very stable and so far no issues, I'm very happy with the results. I did previously have that stylus on it, the cantilever is very stiff by comparison hence the higher tracking weight required. If the stylus is designed for a low tracking weight I can't see why it would be a bad option myself if all tracks correctly with no distortion and good sound, but each to their own

Matt I have to disagree here.

- Seeburg made 2 gram VTF standard in August 1966 with the intro of the SS160 model and new pickup which was a variant of the Pickering V-15.

Rowe-AMI's 1100 series changer was capable of 2G in 1962 but the primitive Shure M77 required 4-5 G due to low compliance. I have two 1967 Rowe hideaways in service, both have run at 2G for over 20 years.

When modded the Rock-Ola "Accu trak" arm and bearings perform with the best of the machines and can use modern high quality carts.

I have 9 Seeburgs from the 1950's with modified arms and later pickups in heavy use locations, all run at 2 gram. In commercial service low VTF is essential in preserving styli and records.

Even the older, cruder 1950s machines can run at 2-3 grams and use modern pickups when the arm is properly balanced.

Here is a 1958 AMI "I" 200 with counterweight that replaced a crude finger spring: http://s1192.photobucket.com/user/Rob-N ... ort=3&o=65

I get your point about how people regarded jukeboxes and their sound, but in the commercial operating world that began to change in 1986 when Seeburg introduced the first CD juke. After that hit the street it raised the bar on what was expected of a commercial phono. Upgrading pickups in the old machines is only one step in making them more acceptable in a modern context.

The question of "how light is too light" depends on two main factors:

1) Quality of tonearm bearings.

2) Compliance of the stylus cantilever.

The velocity of the groves and how heavily modulated they are also comes into play, but the main factors are 1&2.

Within those limits a more compliant stylus with less cantilever mass means lower distortion and wear. The machines just sound better when the input is clean.

As long as the stylus is not climbing the groove walls as evidenced by distortion the VTF is OK.

BTW: It would be nice if this site could cache the text and pics of Psychman's mod since the poor tracking in Rock Olas comes up every month or so.

Rob/NYC

Ill keep the images in my photobucket, but would be good if posts and content could be stored by Phonoland for future users

It's been a while since I've had a rockola in the shop for repairs, but just exactly what do they use for a horizontal bearing on those tonearms?
Ball bearings?
Sleeve?
And does the weight of the pivot assembly ride on a single ball, or a polished washer?

Horizontal friction becomes and issue here with light tracking forces, and asides from any "drag" of the wiring involved, even a minute amount can affect things.

Also, the end of record trip switch - does it add to the lateral friction near the record's end?

Believe me, 5 grams is not a record-killer - old records my parents had were played frequently on a (stereo) record changer at 5.5 grams over the years, and still sound great today.

The trip switch shouldnt load the grooves when set up right, mine doesnt. Im not sure the bearing types exactly I know what they look like but not what theyre called, Im sure Rob will know better.

While the weight exerted on the stylus is less, this setup uses a counterweight to just distribute the weight differently, so not sure what if any impact it would have on the free movement of the bearings as they are carrying the same weight unless im mistaken. This has crossed my mind but after trying it Im very pleased with the results, my M44-7 sounds much better with this new stylus compared to how it sounded with the "stock" rockola stylus when tracking around 5g.

I accept what you say about 5g not being lethal to records - after all if all these old decks killed records that quickly I doubt we'd have much original 60s stuff left! That said some old records do seem to have lost some of the top end frequencies, but maybe they had worn stylii or badly setup tonearms. Its an interesting topic and one thats debated heavily!

If the complete tonearm assembly - pivot block, arm, cartridge, hardware, etc weighs say, 1 pound, it exerts a certain amount of gravitational-induced friction on the horizontal bearing itself.
Now, adding a bolt, nuts, and a handful of big old washers at the rear of the arm, simply increases the overall weight, AND friction on that bearing.
Perhaps not much, but maybe a few more ounces.
Nevertheless, the added friction now to the lateral bearing is increased.

A point to check is to play an out-of-center record, one with slightly off-center pressing, and watch the stylus cantilever closely as it plays.
If the cantilever appears to "sway" back and forth horizontally as opposed to the cartridge itself, it's reacting to the mass and friction in the arm's horizontal movement.
For instance - / | \ | /
It simply cannot follow the "in-out" horizontal movement of the groove easily enough.
This can sometimes be heard, and also is not too good for the records themselves, because of the wear pattern possible.

The bottom line here is, not to worry so much about vertical tracking force as damaging records, but to keep horizontal friction as low as possible.

You make some good points Matt. I do have quite a sensitive ear for this thing and haven't heard it yet, it sounds fantastic. I will grab an off centre pressing, or even stop a small centre record then Unevenly place something I'm not fond of in place of it. though come to think of it it's played one or two off centre records and I've seen the arm move with the tracking so may well be fine

Psychman wrote:You make some good points Matt. I do have quite a sensitive ear for this thing and haven't heard it yet, it sounds fantastic. I will grab an off centre pressing, or even stop a small centre record then Unevenly place something I'm not fond of in place of it. though come to think of it it's played one or two off centre records and I've seen the arm move with the tracking so may well be fine

Indeed, the arm may move along with the out of center record groove, but carefully watching the stylus cantilever - does IT sway in the cartridge body as well?
Too compliant of a stylus, along with the lighter tracking forces used for such a compliant stylus can be detrimental to records, due to the uneven forces upon both walls of the groove. - IF horizontal friction is at all excessive (and noticeable as mentioned) in the arm pivot.

This is why in my opinion that a reasonable stylus tracking at a higher level would be more immune to the frictions mentioned. - actually lessening the amount of record wear over time.

Jukeboxes are workhorses, and built as such, but I've yet to encounter one with fine, jeweled frictionless pivots such as upscale high fidelity turntables are equipped with.

This does seen to happen, at least a little. I compared it with my late 70s technics deck with its ortofon 2M cartridge and while the technics stylus barely flexes at all horizontally, the Rockola is very noticeable. I don't think this writes off the concept however, I'll do some tests as I can certainly reduce the hardware I used, move them further out and infact up the tracking weight, which would reduce the down force on the bearing. I did use bigger washers to look pretty but maybe I've added a little too much weight

If we're going to these levels though Matt, I wonder if this will always happen to an extent on these tone arms. Perhaps the drag occurs on stiffer stylii but the grooves suffer more as the stylus doesn't move

Folks, the original problem was radical imbalance of the arm re: fulcrum point.

As designed the arm wants to fall forward, thus placing all the stress (such as it is) on the horizontal pivot. Although the post 1963 R-O arm was a big improvement over the earlier version, the bearing was still just a simple sleeve with a hardened steel post inserted. There -may- be a captive ball in the well.

Anyway, once properly counterweighted the bulk of the weight on the bearing becomes close to true vertical with just a residual imbalance to provide tracing force.

The only reason for the original design was cheapness -that was it. Crap designs such as this are what gave jukeboxes such a bad rep for destroying records and poor sound.

Here is a list of R-O's and AMIs that i've owned and modded with a counterweight:


Rock-Ola

1458 (120 sel)
1465 (200 sel) (2qty)
1496 (120 sel)
"Tempo 1" (200 sel)
"Princess" (100 sel)
"Grand Prix" (160 sel)
432 (Grand Prix Junior 160 sel)
Another from 1968 don't remember mod.
-------------------------------
AMI

"E" (Ugly as hell)
H-200
I-200 Mech sel
J-200 (stereo)
Continental 1 (200 sel)
Continental 2 (100 sel).

ALL of these had the same crude arms and all were "civilized" with careful modding that included a counterweight, new pickup wire, bearing polish-lube and in the case of some AMI's I also replaced the trip switch with light weight leaf contacts. If the tonearm wire has a cloth covering I cut it away back to teh strain relief. Cloth will stiffen the wire and load the cart.

The new carts were Pickering DAT-2 tracking at 2-3 grams.

I'd discussed modding an AMI J-200 back in 1986 to use a better cart than the GE VR. I was told 'forget it, those old arms are crap and the stylus will wobble and skip...get a Seeburg". The person was head of the service dept at Albert Simon Co. the Seeburg dist here in Manhattan so that might have colored his opinion a bit .

Yeah, a counterweight adds mass but it more than compensates for that with greatly reduced friction.

There is NO argument to be made for running above 3 grams on these arms once all the above has been done.

Rob