Hum Problem with Grado

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,
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.

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