Changing a TP4 / P-Mount Cartridge for an AT85EP

Now that my Technics direct drive turntable it is permanently installed in a system it’s going to get regular use. The stylus has gaps in it’s known history, so I’m going to change it, just to be safe.

Existing P-Mount Cartridge
Existing P-Mount Cartridge

It is fitted with a P-Mount cartridge, which I’m also going to change. In theory changing such a cartridge should be a 5 minute job. I’m going to take measurements as I go along, so it may take a little longer.

Before starting let’s have a look at the setup.

Original settings
Original settings

The tracking pressure and anti skate are set to the factory defaults. All should be good. Now let’s have a closer look.

Original tracking force
Original tracking force

Measured tracking force of just over 1.07 g. This is comfortably in specification, but perhaps a little low.

Test Record
Test Record

In order to test and set up anti skate force a test record is required. Here I use a Decca test record with an “Anti-skating band”

Setting anti skate
Setting anti skate

The test record has a plain track for setting anti skate. The absence of grooves means that the arm will drift towards the centre or edge if anti skate is not set correctly.

Anti-skate setting dial
Anti-skate setting dial

To get the arm to stay put I had to turn the anti skate setting right down. Something is not right here!

epc-p33 Bent cantilever
epc-p33 Bent cantilever

Here is a close up of the stylus as originally fitted to the EPC-P33 cartridge. A bit bent methinks. That would nicely explain why the anti skate was off kilter. The last owner recon’s this must have happened during a house move, when the turntable wasn’t in regular use, so nobody noticed. To be fair, I used the turntable several times and didn’t notice anything greatly amiss.

EPC-P33 Cartridge
EPC-P33 Cartridge

I only had a sketchy history of my Technics direct drive turntable, so I decided to play safe and change the cartridge as well as the stylus. The cartridge is an EPC-P33, which is what would have been factory fitted to this PL QX200 turntable. I’ve been told that the stylus has been changed at some point. This makes sense, since it doesn’t look original but it does look to be in good condition, bet cantilever aside! New Stylus are available for about £30.

Audio Technica AT85EP
Audio Technica AT85EP

The replacement cartridge is an Audio-Technica AT85EP. At £35 for an elliptical stylus in a cartridge this is excellent value, and only a few quid more than just a conical replacement to stylus to fit the ‘P33. I already have good experience of Audio Technica cartridges on my other turntables, and there is not an awful lot of choice for new P-Mount cartridges. This was therefore a no-brainer.

New Cartridge fitted
New Cartridge fitted

Fitting the cartridge is just as simple as removing the single screw you see in this picture. The cartridge then just un-plugs and the replacement goes back in. Replace the screw to secure and you are done.

Tracking force measurement AT85EP
Tracking force measurement AT85EP

Using the electronic scales we see that tracking force is 1.3 grams. The spec says 1.0 to 1.5g, with 1.25g standard. This is about right then. Tracking on the slightly heavy side makes mis-tracking less likely and is good within spec.

Anti Skate setting for AT85EP
Anti Skate setting for AT85EP

Back to the test record then, and re adjust the anti-skate force.

Final Settings
Final Settings

We can now see that with the arm settings lined up with the factory default settings all is good. This is indeed evidence that P-Mount cartridges are a simple plug and play replacement.

The new cartridge is noticeably clearer. I also don’t need to worry about a dodgy stylus damaging my records. Well, not for another 300 hours anyway.