Tonearm for Technics SP-15

chakster, others,

If looking for a used EPA-100, what are the things to be concerned about?

questions to ask? 

Elliott, the Technics EPA tonearm guru is a fellow that goes by JP and can be found at the HiFi Haven forum as well as other places. Do a search on that arm there, he does a repair to the fragile ruby bearings as used on them.

Interesting to read the ad copy on this arm in the Ebay add you linked. It makes it seem that the armtube is made of Titanium Nitride. Had to look into that as that stuff has always been vapor deposited as a very hard wear surface used on cutting tools. I never heard it used as a material and looking into it all I see is surface treatments. So the arm tube is aluminum with a surface treatment, very dubious as to it’s benefit. I have the same type of arm tume on my Technics SL-M3 LT stashed away.

BillWojo

@elliottbnewcombjr you have to make sure about the bearings, loose bearings must be avoided.

@billwojo epa-100 can be found in perfect condition and you don’t need a pepair "guru" if you will buy a perfect sample. Broken samples must be avoided from the start.

"The EPA-100 tonearm represents several significant advances in tonearm technology. A variable dynamic damping system which permits the user to tune the arm for compatibility with virtually any cartridge now available. An extremely stable 4-point Gimbal suspension employing ruby ball bearings which maintain static friction at 5mg or less for movement in any direction. A titanium nitride shaft which is light and also resistant to flexing and resonances. These elements all contribute to one end, keeping the stylus in optimum contact with the record grooves. Although this many seem elementary, the ability of the EPA-100 to perform this function in a high grade sound system can make a noticeable difference in the clarity and openness of the resulting sound."

Dear @arneama22  : Your Grace is very good tonearm, yes not so easy to change cartridges as tonearms with removable headshells. You can find out a Grace 1040 that's really good removable headshell design.

Btw, @billwojo you are rigth about Technics tonearms and the EPA 250 that I still own is even superior to the EPA 100.

The 250 comes with 3 different arm wands and with the same VTA unique mechanism made it with the EPA 100-MK2 that's that VTA mechanism the best ever made in any tonearms including today top models.

Here with the SP-15 OP one:

Regards and enjoy the MUSIC NOT DISTORTIONS,

R.

Most of the arms I see, if not obviously broken (shattered/missing balls), will typically present with at east one pitted ball in a bearing. These can seem to work fine until that pit works its way around to the running surface of the race or pivot, at which point the bearing is ’loose’ with play. It’s also typical for there to be fine detritus in the bearing increasing friction.

Half the time on seemingly good arms I find indentations from the balls in the pivot surface. These surfaces need to be re-ground and polished out for best performance, or the arm will tend to have resting positions when the balls rotate around to fit in the indentations. Usually because of the detritus in the bearing the friction is high enough that this condition isn’t obvious from obersvation.

The silicon nitride balls I use have better roundness and surface finish and a lower friction coefficient than the original rubies. This makes the outstanding bearings in these arms just a bit better.

With these arms, even in poor condition relative to their potential, the performance is beyond most contemporaries. This is to say that people don’t realize they’re leaving performance on the table. If your EPA-100 is nearly impossible to get to hold balance and moves around on air currents in a seemingly completely still room, then there’s an excellent chance it’s still in great shape. If not, it could be a lot better.

EDIT: Nearly forgot - on all of them with original wiring the insulation has reacted with the copper causing a good deal of corrosion and fragility.