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Possible Cure for Collapsed Stylus Suspension

Hi, first-time poster, long-time lurker here. I want to give tremendous thanks to wualta for his instructions on tightening up the suspensions in Audio-Technica cartridges. THANK YOU!!

I bought an Audio Technica AT413E off eBay last week and while I was testing it today I found it was bottoming out at 1.5g. I adjusted it to 0.75g and it was riding close to the record, but not touching.

Being the meddling engineering major that I am, I searched up what to do with a failing suspension, since the stylus looks hardly worn under my microscope and it's the nice original nude square-shank 0.2mil x 0.7mil elliptical diamond. Definitely wanted to try rescuing it. I found this thread, wualta's post, and tried my hand at the repair.

I found the set screw inside the stylus, but no rod out the back. So, what I did was I loosened the screw, used a pair of small pliers that had flat ends on them to push the stylus assembly into the body, tightened the set screw with the suspension compressed, and put it all back together. Nice and springy but not overstrung like myself, ha-ha.

Anyway, I put it back on my Mitsubishi DP-EC7 and set the needle down on an alignment protractor with the counterweight/antiskate set at 1.5g. Well would you look at that, it sits up like the rest of my AT carts. VTA looks alright from the naked eye. The final test was Babylon Sisters on my Gaucho LP, and WOW I was not expecting the sonic difference I heard! Lots less crackling, no sibilance whatsoever on S-sounds, no tv-static "artifacts" attached to horns or vocals, so very natural sounding. I was floored.

Once again, thank you wualta and everyone else that contributed to the thread. You all saved a very nice stylus that I got on the cheap!
 
Very glad it all worked out, and thanks to DG_lite for the very kind words, but the thanks should go to AK member lini/Manfred who had for years been preaching the loosen-the-setscrew method of curing cantilever droop on Audio-Technica's styli. I was simply passing on his experience, which by the time I posted in this thread had become my own experience, so I at least had some confidence in my diagnosis.
 
I just unsealed a mint Azden YM-P50VL ( Empire 875XLT ) that sounds a bit lackluster. I suspect the rubber has hardened. I'd read of using WD40 to rejuvinate stylii but couldn't find this thread :rflmao:

So thanks everyone for all the research & info posted here.

Since it's not collapsed, I'll look into rubber softeners instead: these are the two prime candidates I see

1. Liquid Wrench Silicone Spray
2. Rawn Re-Grip with methyl propasol acetate

pic:

P50VL.jpg
 
bolero said:
I just unsealed a mint Azden YM-P50VL ( Empire 875XLT ) that sounds a bit lackluster. I suspect the rubber has hardened. I'd read of using WD40 to rejuvinate stylii but couldn't find this thread :rflmao:

So thanks everyone for all the research & info posted here.

Since it's not collapsed, I'll look into rubber softeners instead: these are the two prime candidates I see

1. Liquid Wrench Silicone Spray
2. Rawn Re-Grip with methyl propasol acetate

pic:

View attachment 3562201
Click to expand...
How many hours on it? Why not give it 30-40 hours to break in before making judgement.
 
Good idea. That thought crossed my mind, do they really need time to break in?

0 hours: I ran it for a few minutes but compared to my AT 152LP the output level was low & less bass response. I was concerned running it on dry rubber might be bad for it.

Later when I took that pic I carefully pressed on the cantilever & the rubber is pliable. So maybe it does need breaking in?

I'll look up the specs on both too & compare. Maybe that's normal.
 
Last edited:
I hope this isn't off topic, but to followup the 152LP does have 1mV higher output than the P50VL & wider freq response. Presumably in the correct cart.

152LP:
Frequency response: 5 to 35,000 Hz
Vertical tracking force: 0.8 to 1.8g
Channel separation: 31dB
Output: 5mV
Vertical tracking angle: 20 degrees
Stylus: nude square MicroLine
Cantilever: Beryllium
Load impedance: 47K ohms

P50VL:
Frequency response: 10 to 24,000 Hz
Tracking: 1.25 =- .25g
Output at 1kHz/5cm/sec: 4mv
Channel bal.: 1.0 dB
Separation at 1kHz: 30 dB
Stylus: Vital nude line contact (VL)
Cantilever: UT58 (titanium alloy)
Load: 47k/300pF

5 Hz vs 10 Hz on the low end cutoff might be audible? depending on the rolloff. How many records have <30 Hz pressed on them??
 
You may wish to include three of the following for treating fatigued rubber-
PB Blaster Silicon and/or RemOil...
These are superb for lubricating minute parts, including gimbal suspensions

AT-205 Rejuvenator is an automotive product used to recondition seals. But it has good results with bringing fatigued rubber back to life. Uses include platter matts, drive belts....

Also, keep a bottle of mineral oil for maintaining any polymer materials suspect of fatigue. Its low cost, neutral and last forever. As a gunsmith for 40+ years, its by far the best lubricant for any metal and polymer material.
 
I have spent a fair amount of time reading this thread and doing research on rubber restorers after having a suspension fail and ordering some NOS and new-to-me styluses. I am avoiding anything with alcohol as a solvent. Alcohols work well at pulling the rejuvination product into rubber, but I'm worried they will dissolve any glue or epoxy that holds the grommet or cantilever in place. Instead, I'm going to test out Dupont's Seal Saver:

The solution in this product is Butane, which is poor at disolving both glue and epoxies. I read the data sheet. I'm not a chemical engineer, but nothing alarming and most of the compounds are used in rubber manufacturing including a surfactant. I also trust dupont to know their chemicals and this product is made for restoring the rubber door, window, and sunroof seals on vehicles. I'll follow the application process popular on this thread of adding tiny amounts and letting it sit for hours. However, I'm going to mix in just a bit of wintergreen oil on any styluses that sag. Back in my days of restoring old cars, I know how much wintergreen oil swells rubber. I once forgot to remove a firewall grommet from my solution of 90/10 alcohol and wintergreen oil for a 2 day soak. It grew to twice its original size! I eventually shrunk it back down by soaking it in pure alcohol to dilute out the oils.

Lastly, after the seal saver, I plan on applying a tiny bit of Aerospace 303 as a protectant. 303 doesn't rejuvinate rubber, but wow does it do a fantastic job of sealing it. 303 has a tiny bit of alcohol, so I'll pour some in a small container and let it sit for a couple days to evaporate the alcohol down before applying it. I have been using 303 on my vehicles and it lasts about a year in the Texas heat and sun. I have also been using it on old rubber TT platter mats for about 2 years now. Every single one still looks as good as the day I treated it. Truly an amazing product, I wish I could get my old skin to look that good!

This is my first try reconditioning a stylus. I realize I'm biased towards automotive products, but for me they are proven to work. If anyone has tried or is more knowlegable about these products/chemicals, please let me know! I plan on testing on a grommet I pulled out of a broken Empire 238-DET stylus. I'll check at different intervals of treatment times. Then move on to the good stuff.
 
Follow-up: I recently removed, examined, and swapped the suspension on an old, sagging Empire stylus. See this thread for details.

The suspension grommets were in surprisingly good condition. I've seen rotten rubber and failed neoprene from my years restoring old cars. The suspensions I removed were nothing like those. The rubber was resilient, sharp edges, no cracks, and it retained it's form after getting stretched during removal.

I suspect the adhesive material holding the cantilever to the suspension was the root cause of my saggy suspension problem along. The adhesive eventually failed, allowing the cantilever to sag badly and and eventually push back into the shank.

There were no tie wires on my stylus, just a small "crumb" of adhesive. I painted epoxy all around the cantilever to bond it, which resulted in an overly stiff suspension that required extra tracking force. If I were to do it again (on an Empire stylus) , I would use something like a tiny insulin surrenge to inject a small dot of liquid epoxy at the top of the cantilever between the suspension and the cantilever.

Empire used a small "crumb" of adhesive at the top of the cantilever on many models instead of tie wires. Therefore, a carefully placed dot of adhesive *may* be a possible fix for stretched or broken tie wires as well.

Liquid epoxy is not viscus, practically weightless, and bonds with a permanent chemical reaction that can withstand solvents like alcohol and other contaminants.
 
Interesting that it wasn't a rubber failure but an adhesion failure. Call it crumb failure ["crumb" simply because that's what it looked like when I first saw it]. I like the idea of using an adhesive to replace a failed crumb, though that doesn't explain how or why it failed. Did your crumb remain stuck to the cantilever, or did it simply lose its adhesive properties altogether?
Thinking out loud, I'm wondering if something both adhesive and flexible, even rubbery, wouldn't be safer, especially considering your experience with epoxy.
 
DG_lite said:
Hi, first-time poster, long-time lurker here. I want to give tremendous thanks to wualta for his instructions on tightening up the suspensions in Audio-Technica cartridges. THANK YOU!!

I bought an Audio Technica AT413E off eBay last week and while I was testing it today I found it was bottoming out at 1.5g. I adjusted it to 0.75g and it was riding close to the record, but not touching.

Being the meddling engineering major that I am, I searched up what to do with a failing suspension, since the stylus looks hardly worn under my microscope and it's the nice original nude square-shank 0.2mil x 0.7mil elliptical diamond. Definitely wanted to try rescuing it. I found this thread, wualta's post, and tried my hand at the repair.

I found the set screw inside the stylus, but no rod out the back. So, what I did was I loosened the screw, used a pair of small pliers that had flat ends on them to push the stylus assembly into the body, tightened the set screw with the suspension compressed, and put it all back together. Nice and springy but not overstrung like myself, ha-ha.

Anyway, I put it back on my Mitsubishi DP-EC7 and set the needle down on an alignment protractor with the counterweight/antiskate set at 1.5g. Well would you look at that, it sits up like the rest of my AT carts. VTA looks alright from the naked eye. The final test was Babylon Sisters on my Gaucho LP, and WOW I was not expecting the sonic difference I heard! Lots less crackling, no sibilance whatsoever on S-sounds, no tv-static "artifacts" attached to horns or vocals, so very natural sounding. I was floored.

Once again, thank you wualta and everyone else that contributed to the thread. You all saved a very nice stylus that I got on the cheap!
Click to expand...
Do you have a pic of what you call a set screw on the stylus?
 
wualta said:
Did your crumb remain stuck to the cantilever, or did it simply lose its adhesive properties altogether?
Click to expand...
The crumb remained stuck to the suspension. It pulled off the cantilever, which allowed the cantilever to slide way back into the shank. I picked this up off ebay hoping for a useable stylus. No idea how it was treated previously.

That said, the cantilever was the tapered style. Based on my understanding that should make it many decades old with a very old suspension as well. The suspension really was in great condition.
 
gary7 said:
Do you have a pic of what you call a set screw on the stylus?
Click to expand...
There was no set screw, I didn't get a pic as I was trying to get everything aligned before the epoxy hardened.

I believe what you're referring to an encasing or sheath on the rear of the cantilever. A ridge at the end of this encasing that lined up perfectly with the suspension when I measured depth for reinstalling the cantilever. The encasing was flared just a hair and that hair seated just outside the grommet.

More on alignment: Once installed and with epoxy still wet, I had to rotate the cantilever so the diamond would fit straight into record grooves. I did this with the turntable unplugged, installing the tip and "playing" it around the grooves of a record slowly by hand with reduced tracking force and zero anti-skid (hoping the record grooves aligned it better than I could by eye). Then let the epoxy set.

I'll be testing it on old records to inspect for damage.
 
Again, thinking out loud:
Having had a crumb let go after being in an ultrasonic bath containing a dash of allpurpose cleaner, I wonder if a previous owner tried something a bit stronger, ultrasonic or not, on yours. I was lucky; my wayward crumb reattached itself after being rinsed and dried, and all was well. But I can imagine one being damaged by a more aggressive treatment.
I've never tried it on an Empire stylus, but maybe something like WD-40 wouldn't be ideal on a crumb-equipped stylus.
 
Last edited:
following up: I started using the Azden in post #723 to see if it breaks in. Suspension seems to be working fine

I read this on the paper spec sheet in the box: "Separation at 1kHz: > 30 dB"

which theoretically is better than 30dB mentioned in post #728

I'm thinking the 4mV vs 5mV output might be why I didn't think it sounded as good as the AT. Typical audio trap to fall into: volume differences
 
gary7 said:
Do you have a pic of what you call a set screw on the stylus?
Click to expand...
The white painted thing in the hole there is the "set screw." It keeps the cantilever from falling out but can also regulate the compression in the suspension.
 

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