Hum Problem with Grado

Grado's are unshielded cartridges and hum is common. I also use a Grado. My amp has separate gain controls on the back which I adjust down. The hum is still there but only from very close to the speaker not from the listening position. I've also read about some people gently moving the wires behind the cart a bit to reduce hum. Another aspect might be in the interconnects you are using, if they are unshielded, it could cause some hum. Go to the archives here and at Audio Asylum and search "Grado hum" for more info.

Grado does make a special version of their cartridges that are sheilded for hum problems with Rega's. I'm sure they would work well with the VPI.

This is odd. The only thing on the Aries that might cause hum is the motor but it is on the other side far away from the arm. It shouldn't cause the Grado to hum. Does the hum get louder as you move the arm towards the spindle? If not, I don't think the motor is the cause.

If it hums only during play, it is highly likely that you are hearing the mechanical hum caused by the vibration of the motor. This is a well-known problem of the Aries. To test that theory, you need to take the rubber belt off, lower the cart on the platter, turn on the motor, and turn up the volume. Now while the motor is running, carefully lift the motor up slightly and see if the hum goes away. If it does, you have vibration problem. An easy way to reduce it is to put a thick mouse pad under the motor. You can reduce it even further by replacing the stocked rubber feet with Tender Feet from Herbie’s Lab or run the motor through a SDS at reduced voltage.

How far is Grado from speakers? Are the speakers shielded?

I have a similar problem with a Grado Black on a new Rega Planar 3 - the hum really appears as the cartridge end of the tonearm reaches the end of the record - within 4-5" of the spindle.

I turned off the motor and moved the tonearm (not touching the platter) over the spindle, and there was no hum - but with the motor on, the hum appears as the headshell approaches the spindle and gets worse when I move the headshell right over the spindle.

So maybe this points to motor vibration being source of the hum, since the motor is on the side away from the tonearm and as the cartridge approaches the spindle it is always getting closer to the motor. Although in this situation, there is no contact with the LP or platter, so the vibrations would have to be transmitted through the air.

Can anyone advise, do the Rega upgrade kits that include vibration damping mounts help this situation? Do other cartridges have the same degree of problem?

Cserbell,
Good detective work, but the hum is not caused by physical vibration of the motor. It's caused by leakage of electromagnetic energy from the AC motor coils. EM energy travels through air pretty readily. That's why radio works.

Most cartridges are electrically shielded aginst EMI. Grado's are not, and are thus famous for humming. If you search here or on Vinyl Asylum for "grado + hum" you'll get a million hits. If you search for "most other cartridge names + hum" you'll get far fewer.

Possible solutions:
- shield the motor, try wrapping some foil around it
- shield the Grado, as mentioned by Ramstl
- dump the Grado

Cserbell,
In your case, it was not caused by motor vibration. It was caused by the electric magnetic field generated by the motor since the Rega placed its motor under the platter near the center. You may try to reduce the hum by lining the underside of the platter with one or two layers of mu-matel sheet. Mu-matel can be cut in shape with a utility knife and can be mounted with double-sided tape. But they have very sharp edges (guess how I know). So handle with care.

I recently bought my VPI Scout and set it up with a Grado Red just to get me going. I noticed a hum but only after a rather loud listening session where I left the volume way up and went to change a record. I was only a few feet from my speakers and noticed it. Turning the volume way up increases the hum...but I would never even consider listening at those levels. I tried grounding the table to pre-amp, less humm. I switched from my Kimber Hero's to AQ Diamondbacks and got even less hum, but sound was not as good.

Right now I still get an audible hum at high volumes when I am close to the speakers. Normal listening is ok. I'm sure it degrades the sound some and because of this will more than likely change to a new cartridge sooner than I thought.

Same problem for me with my VPI M4 and high output Grado Sonata. Not a huge hum, but motor induced and noticable at high volume levels. I shielded the motor assembly with two layers of mu metal and the hum is pretty much completely gone, I'd say 90% reduced. I could only hear the hum on the last three inches towards the spindle when not actually playing. But you know it's there. Easy to do and effective. A very good tweak for me because the cartridge wasn't cheap. Good listening.

http://www.lessemf.com/mag-shld.html

This might help: https://www.haglabs.com/collections/accessories/products/humbucker

Another way to eliminate the hum is simply to see to it that the motor has a wire between it an the tonearm ground. 

I tried that too, connecting ground wire to motor (bearing too).  Didn't do a damn thing... 

In this case, the problem is magnetic, and you have to deal with it very differently.

Nice rule of thumb:  If you hear "buzz", it is electric field coupling, add a ground wire.  If "hum", then magnetic field coupling, add distance. 

I have NO hum with Grado XTZ on all my turntables (i have 7 of them).
You’re better search what atmasphere posted in another thread, the problem is your turntable.