Installed AT33PTG/II cartridge and got nasty HUM. Help!

Based on the many recommendations on this site, I decided to try the Audio Technica AT33PTG/II moving coil cartridge. Turntable is a Linn Lp12 with Ittok tonearm. Took it to my Linn dealer for installation.

Bad news! There's a pronounced hum in the right channel. We're wondering if the cart I received is defective. Is the right channel ground supposed to be grounded to the body?


The Linn tech said it would be helpful to test another AT33PTG/II and find out if mine is defective or that's the way it's designed (making it incompatible with a Linn turntable with Linn arm).

If someone could check their AT33PTG/II with a voltmeter that would be extremely helpful.

Check the electrical connection between right channel pin (green) and bottom of cartridge bottom.


Any other advice?
Thanks!

 

I have contacted Audio Technica with hope they will get back and be able to help.

 

I'll look at mine tomorrow but in the meantime have you tried different interconnects? Balanced interconnects can sometimes cause trouble.

 

Thank you for the reply!

The hum is apparent on the bench equipment in the store. The tech tried a couple preamp and cable options while I was there.

The hum is only in the right channel.

 

Any experts out there who would like to suggest a solution?

 

If the dealer has another table maybe you could try it on that on?

 

I have no helpful suggestions, but wish you good luck. Sounds to me that you may have received a faulty cartridge from the factory??? It can happen and I'm usually the one who gets the bad one. I have been curious about trying that cartridge myself. I have been very pleased with my modded Denon 103R, but I'm always on the look-out for other good cartridges that don't cost thousands! Please keep us posted.

 

Are you using a step up transformer?

 

Tech told me the hum is present using a SUT, also present when plugged directly into an active phono stage.

 

^^^^^This^^^^^^
Where did you buy the cart? I didn't realize they were sold in the USA through authorized dealers.

 

I assume they have swapped out leads L/R going out from the table and it follows to the left. Same with the cart pins. Those two moves should isolate cart from tonearm wiring, but that's so basic I assume they have done that.

So, as mentioned above, testing the cart on another table/arm is going to confirm it is something about the cart.

 

I agree. I have several MC cartridges, one of which is the original AT33PTG, and I've never had hum coming from only one channel.

jeff

 

Thanks to everyone for the input and advice.

Audio Technica technical support personally called me and explained that the cartridge I have is likely defective. Tests by the local tech confirmed that it is defective.

Now to return it...

 

There are no US dealers for the AT33PTG/II, Audio Technica confirmed this to me during a phone called earlier today.

I bought the cartridge on eBay.

 

That's great service! I was asking about source of purchase because some manufacturers don't support "grey market" items. I buy carts that way all the time but have been really lucky not to have to use a warranty.

Nice to find out that Audio Technica supports there stuff!

 

Wait, I may have misunderstood. Is Audio Technica supporting it, or do you have to send it back to the eBay seller?

 

Audio Technica USA said they would accept the cartridge and they would test it for defects, but they could not send me an exact replacement.

I have to try to return the defective AT33PTG/II to the eBay seller.

 

I wonder what replacement model they would send.

 

As the cartridge is defective, and verified by a tech., a refund should be straight forward.

Most likely the "EV", as it's the closest to the PTG.

jeff

 

I'd take an EV if it comes with a warranty, or if the eBayer turns out to be a flake.

 

Let us know how it works with the eBay seller.

 

Thank you for asking. The eBay seller (who is recommended on this Forum) has not responded yet to my notice of the defective cartridge.

 

If it's the one I'm thinking of, they will come good in the end but you have to be (very politely) persistent. These days I pay the extra and buy from authorised dealers, for an easier life and peace of mind.

I'm pleased you found the answer to the problem, at least.

 

I have heard of QC problems with the 33PTG before. Strange it's unavailable in US. While I don't see any dealers doing it it is available direct from AT's EU cartridge site. It appears all their models can be purchased here - even ones that were previously Japan only.

http://www.audiotechnicashop.com/index.php?route=product/category&path=93_50