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EQUIPMENT FORUMS >> ZP3 / ZMC1,2,3 >> ZMC hum
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Message started by gfxmla on 06/08/17 at 22:17:50

Title: ZMC hum
Post by gfxmla on 06/08/17 at 22:17:50

Hi forum,
I'm the proud owner of a new (to me) ZMC2. I'm using a Hana HL cartridge, which is a relatively high output cart at 2 mV. I noticed an excessive amount of 60 Hz hum so I moved the ZMC as far away from my ZP3 as the interconnects will allow. Hum is tamed somewhat but not completely.

I know the ZP3 should be able to take 2 mV without a SUT, but I also have a 0.3 mV low output cart to play with, hence the ZMC2.

I have a set of 4 foot long interconnects on order from Blue Jean cable for their extra shielding, but in the meantime, does anybody have any pointers to get this thing tamed all the way down? Is it really just wacky placement and IC shielding?

Also, I read that the the Decware DSG ics are shielded, but they seem to pull more rfi then these Audioquest Diamondbacks I had laying around. So what gives? :-/

Thanks-Geoff.

Title: Re: ZMC hum
Post by Archie on 06/09/17 at 01:27:52

If you haven't already, you might try all combinations of grounding between the TT, ZP3 and ZMC2. I ended up grounding just my TT to my ZP3 (I have a ZMC1 and it doesn't add any noise). Other combinations weren't particularly bad but this was best. I haven't found much, if any, difference in noise by using shielded interconnects but I use the Decware DSGs anyway. This may be related or not but I don't have wireless running on my computer router (just a cable) and I don't seem to have much RF interference in my house. Whenever I drive by a bank and loose my FM radio signal, I'm reminded how destructive/disruptive those signals can be.

Title: Re: ZMC hum
Post by gfxmla on 06/09/17 at 15:04:28

Hey Archie,
Thanks for the reply. Yep, I've tried various configurations of grounding with the ZMC. I hooked up a jury-rigged grounding scheme from my TT, from my ZP3 and also without any grounding at all and there was no discernible change in the hum.

Let me back track one of my statements. It's not actually RF interference, but rather EM interference from the other elements in my system. One thing I did discover is that if I twist my input cables down away from the transformer of the ZP3 the hum reduces, but does not disappear entirely. Seems the only time it is completely silent is when the ZMC is a few feet away from the rest of the rig. Anybody else experience this?

Title: Re: ZMC hum
Post by Archie on 06/09/17 at 22:18:58

Geoff,

My ZMC1 is a couple feet from my ZP3 and over an inch and a half of wood is between them. I don't remember if I ever had them closer together. I've never had luck reducing any noise by moving components around but I think others have.

Title: Re: ZMC hum
Post by Lon on 06/09/17 at 22:32:22

The Analogue Productions SACD

Title: Re: ZMC hum
Post by Syd on 06/10/17 at 21:47:16

You cant help but try all the earthing and positioning combos, and even tube rolling the ZP3. A sweet spot should occur at some point. Yes even moving the i/c`s by twisting them in the sockets makes a difference. I`m still using unshielded DSR`s throughout and they pass close to tranformers in places. It`s wierd, they should be humming but they`re not. My tonearm cable is at full stretch before it reaches the ZMC1, around 4 ft. 1/2 mt to the ZP3 and a metre to the CSP2+.
One glorious balancing act....it seems tailor made. :)

Title: Re: ZMC hum
Post by gfxmla on 06/10/17 at 23:22:12

Indeed it does...lol.

So, I got my Blue Jeans cable ICs today and slapped them in. With a quick audition and the ZMC RIGHT NEXT to the ZPF's transformer the hum seems to be gone.

I'm going to play around with positioning and swapping out different ICs to see if it returns, simply for the sake of getting to the BOTTOM of the thing. But at least now, I can say I do have non-intrusive hum in my system.