JVC Victor Tonearm Counterweight Sag Repair

Another Example of 'Expectation Bias'

assume, wish it could say, I am an audiophile, so is the hardware store guy!

put your glasses on: across from the marks ’00’ (not ’’OD’) (letters or numerals?)

which in plumber speak is size # 00 which, as I wrote, as the package is labeled, is 1/2" OD which is for a valve for a 1/4" line. See the washers for larger lines: 3/8; 1/2; 5/8; letters ’S’; ’L’; ’M’, a variety of beveled and curved faces.

 

lewm, others 

for others, it would be good to add to this

A. Set Screw Sizes

1. the size designation of the allen key _______? for the single set screw in the counterweight tube. Assuming someone has to buy one. I had one that fit, I don’t know it’s size designation.

2. 1/16" size designation of the allen key for the pair of set screws in the arm post that retain the chrome plated collet. Is there a metric equivalent _____? to 1/16" that fits those set screws? (I presumed they would be metric sizes)

Kit with 30 pieces SAE and Metric, $14.

SAE SET

 

0.028", 0.035", 0.050", 1/16", 5/64", 3/32", 7/64", 1/8", 9/64", 5/32". 3/16", 7/32", 1/4", 5/16", 3/8".

 

METRIC SET

 

0.7mm, 0.9mm, 1.3mm, 1.5mm, 2mm, 2.5mm, 3mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 7mm, 8mm, 10mm.

 

B. Alternate Photos of the concealed brass piece.

My current one has a rubber shoulder washer covering the flat flange at the end and a 8.5mm diameter rubber shoulder covering the inner brass end. That pushes into the chrome collet’s 8.5mm inner diameter

 

This shows the uncovered end of the brass piece, a bit mis-shapened

Mine came rubber covered, I got lucky. It occurred to me, if the brass is exposed, it could be wrapped (with tape, dental floss, plumber’s teflon tape, ...) to 8.5mm diameter (to both center and isolate it inside the collet) (avoiding metal to metal contact).

Other photos of the OEM part and solutions would be good to gather. I added the one above with my others posted.

 

First, I’m not the least bit angry about this, but why do you seem to be? In fact, I am grateful for your guidance. Especially since only you and I seem to care. What you fail to understand is that the photo on the right showing a bunch of black washers most prominently displays a washer that appears to be 1/4” OD. Whereas the packing shown on the left does clearly state that it contains washers with 1/2” OD. That is why I sought clarification. That was my only point. Anyway I obeyed the package label and bought 1/2” OD.

lewm

I was just having fun, i’m done, never angry. I’m in love with my metal ruler and quite happy with my phone’s camera.

When I joined in 2019, several others seemed to want to solve this problem for these tonearm models, which, when fixed, is superb, I like it equally with my prior favorite Acos Lustre GST-801. I put it in place of my 12.5" arm, effective length 11-1/8", more precise anti-skate while playing, and removable headshell.

I just received the S version/removable headshell version of my 3rd arm, Jelco SA250 that I found in Germany. I need to ease the post hole over 4mm to install it in place of the Mission 774 which is a Jelco 250ST (210mm S/P distance)

Please add any answers/photos when you take yours apart and discover the condition of the inner brass piece.

That leaves me with 2 spare arms.

I acquired my UA7 series tonearm as a piece of a QL10 ensemble, which I bought only to get my hands on the TT101 chassis. After I much modified the QL10 plinth and finally fixed my TT101, I am using it for my Koetsu Urushi.  The very high mass Fidelity Research FR64S with Ortofon LH9000 headshell and B60 base seemed more appropriate for mounting the Koetsu, and I have been very pleased with the results while the UA tonearm sits idle with its counterweight at half mast.  However, by examination, I agree it is a very nicely made tonearm, superior in many ways in terms of quality of construction to some of the high end most costly tonearms we have today. It is well worth repairing.  What do you suppose is its effective mass, assuming a run of the mill headshell of about 10g? Unsubstantiated rumor has it being medium to low mass.