Eminent Technology ET-2 Tonearm Owners

Excellent suggestions and analysis by Chris.

vpi, while I have not used a HW19 for some time and ever since I got my TNT6, I did experience what you describe during the years that I did use it. It was a very low level, volume dependent, hum that I was never able to get rid of. In my case, the cause of it was the HW19’s motor itself; the hum was much worse when the motor was turned off (!). While I could never get rid of it entirely, the level of hum was lowest when I secured a grounding wire to one of the bolts which secure the arm board (ET2, of course) and ran it to the ground lug on the back of my preamp. Hum/grounding issues involve a bit of black magic and the causes and solutions don’t always make sense at first.

In addition to Chris’ excellent suggestions try removing the tt belt and with the stylus resting on an lp turn the motor on and off. Any change in hum level? Then, lift the stylus off the record and do it again to make sure the hum is not simply mechanical noise generated by the motor. Btw, it is not clear from your description of the problem whether you can hear the hum while music is playing. Also, try reversing the orientation of the tt AC plug. These may give you a clue as to what is going on.

Keep in mind that, like Chris, almost from the time I got my ET2, I have used a straight run of wire from cartridge to preamp; no junction box. I also highly recommend this; the sonic benefits are tremendous imo. However, interestingly and unfortunately, while things are dead quite with MC carts, I now (TNT) tend to have noise issues (mostly buzzing) with MM cartridges. Varies cart to cart. My Acutex and Azden are acceptable, the Empire is borderline; and very frustratingly my “Holy Grail MM”, the AT ATML 170 OCC is unusable. With a lot of experimentation and moving wires around as Chris suggests I can get things acceptably quite with most MM’s, but there is always some noise which I wish I could get rid of entirely.

Good luck and I know I am not thinking of some of the other things that I tried. I will post them as I think of them.

**** Excellent suggestions and analysis by Chris. ****; and Pegasus.

Does anyone else use a wall mounted (to the studs of a weight bearing wall) shelf to mount their table? My homebrew turntable shelf consists of heavy duty L brackets from Home Depot and a 1 1/2 inch thick birch plywood shelf. You could stand on my shelf, and no feedback from the floor or woofers. I have a dedicated room and no wife acceptance to worry about. 
-John

Well, thanks Frogman and Pegasus (I think).  Pegasus, while I think I understand your basic proposition, you are way beyond my level of electrical knowledge.  In any event, my VDH Black Beauty is not the low output model.  I don't remember precisely but it is either .5 or .6.  I have not tried the VDH yet on the Garrard/Ortofon.  But I suspect I would not have the hum because, as you observed, the Ortofon is far more shielded as is the Ortofon cable I'm using.  If I understand your explanation, assuming no adverse effect on sq, the Huffman cables may go a long way to solving my problem as they are triple shielded yet very low impedance.

Frogman, no change in hum with motor on or off, plugged in or not plugged in.  And, no, I can't hear the hum with music playing, nor can I hear it more than a foot or so from the speakers at reasonable volume levels without music playing.  It doesn't intrude on the music.  What can I say, I'm an audiophile, I'm OC.  Out, out damn hum!

Chris, I plugged in some longer ICs that I can move around.  Moving them around makes a substantial difference but I can't listen standing on one leg with one cable around my left ear and the other between my toes.  Somehow Keith Jarrett is just not the same. 😜

Thanks to all.  I'll report back if I find the magic bullet.

@vpi: Basically the hum level is strongly related to the efficiency of the magnetic circuit and specially the coil wire diameter.
Increasing the number of turns (because of an air coil or more windings for a higher output) basically means thinner wire.
Thinner wire helps to increase the signal, but even more increases coil resistance (ca. = impedance at audio frequencies). This leads to higher hum susceptibility with unshielded wiring.
Air bearing arms need at least 15cm of unshielded wires for the wiring loom. This increases the minimal level of hum.
With luck and good systematic grounding of arm and any conducting surfaces around the arm / platter / plinth / motor, and shielding the signal cables, grounding them independently at a single point at the preamp/step up input should eliminate any problematic level of hum.
My experience with the ET2 is that it’s unproblematic with low impedance MCs, even with unscreened cables, which I prefer.
In my actual situation with a London cartridge the source impedance of the coils forces me to implement screening – which is what I am working on this weekend...;-)