Air Line Arm Owners- Compressor Electrical Noise


As mentioned in another thread, I finally got the Air Line arm installed on the XL table, on the finite stand, etc. I installed the arm compressor in a separate 'room' (in reality a large walk in closet off the listening room) and powered the compressor from a 'regular' circuit outlet- the system is otherwise hooked up to its own dedicated lines, per standards discussed many times here.
I have been experiencing a periodic electrical 'zap' (sounds like a big ol' scratch on the record) through the system when the gain is up. Since the room lights dimmed when the compressor kicked on, I figured- why fool with the standard circuit to feed the compressor? I had the electrician come back and set up a separate line just for the compressor- having nothing to do with the system wiring or subpanel. (He had already pulled extra wire through the conduit up into the room, so it was no big deal to do this- he installed a high quality receptacle to this extra line, and terminated it at a different subpanel than that which runs the audio system).

Anyway, still that nasty zap. Never out of options, I decided to plug the compressor into a 240v-120v stepdown transformer I use to power the HT system in the same room. (The HT system is completely separate from the analog hi-fi system we are concerned with here).
So far, so good- the compressor kicks on, but no zap.

Still monitoring the situation- wondering whether other Air Line owners have experienced similar problems (which may be reassuring if this is the cause and I licked it) or I am still chasing electrical gremlins. TIA.
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What is the air line made of? Could be building up a static charge and discharging at the TT. Air moving through some types of plastic lines can cause static electricity. What is the humidity in the room now compared to what it was with the zapping going on? Just A thought.....
Hi Whart,
I would contact your dealer first, and then if necessary contact Scot Markwell at themusic.com in California. It may be a grounding issue rather than power. The lines between the compressor unit and turntable are purposely quite long to enable you to find a suitable location for the compressor unit for quiet operation, although you didn't mention any issue with that.
Brian
Yep, I'll bug Scot, who has been responsive to every request as has my new dealer, Bill Parrish. I can barely hear the compressor kick on, mechanically, when the door to the room/closet it is installed in is closed. Putting it further away would start to get really complicated, so the mechanical noise issue is OK. It is really the electrical 'zap' noise that's driven me to audio nirvosa.Thanks, Brian.
Jea- the tubing is as supplied with the arm- it is some synthetic, but it seems to have a reinforced inner lining, and is quite thin, but substantial. There is occasionally a static build up at the TT, I thought, because of the records, not because of the arm. Certainly worth checking, though, thanks. You have been a real help to me on debugging this system.
Well, here's the latest, since it's a holiday weekend and I wasn't going to reach anybody by phone anyway- I rearranged the electronics so that everything is plugged into a Shunyata Hydra, and still have the compressor plugged into my 240v step-down transformer. No more zapping noises! I thought I heard some mild zapping before I took the Shunyata step (the Lamm line stage and TT power supply were originally plugged straight into the wall), but I know that hooking up the compressor to the step-down transformer diminished their severity. It seems like getting everything run thru the Hydras made the additional difference- although the cynics among you may say that, by simply unplugging and replugging everything in, perhaps I did something else!
Dunno, but, right now, I'm making music, not zaps and it doesn't get better than that. (Famous last words, of course).
Thanks for the input, everybody. I'll scream if it starts reoccurring. :)
Hi Whart
I am taking delivery of my Airline this coming Friday. I will let you know if I get any strange noises. Did you do the set up of the arm yourself?
Initially, yes. And, its not insanely difficult. The key- as many have repeatedly told me- is the ability to get the arm absolutely level- which means that once you level the platform that the TT is sitting on- you are using it with the XL, right?- you'll need the ability to further adjust the level of the platform with all 177 plus pounds sitting on it. Before taking delivery of the finite elemente stand, I set up the TT temporarily and achieved rough level using a half-assed system of shims. The finite elemente stand makes it far easier, since the pucks are adjustable from beneath the top shelf after the TT/arm has been assembled.
ONce the stand arrived, I had Bill Parrish from GTT Audio come to set up the turntable properly. Mechanically, it worked fine with my setup but it sounds profoundly better after Bill Parrish did his magic. The VTA adjustment is now zero'd and I can make quick adjustments without tearing my hair out. We are using the adjustment mechanism on the arm itself, not the one that comes with the arm tower.
Highly recommend competent setup just to be sure. And yes, I'd be curious to know if the compressor creates any electrical disturbances in your system. I'm still gonna follow up with Parrish and Markwell on that issue, even though,through the combination of the stepdown transformer and use of the Shunyatas, I may have eliminated the problem.
Hi Whart,

I have experienced the same problems. Problem can be solved by fixing a Zero switch Box in the compressor. Speak to your Kuzma distributor or you can call/e-mail Mr Franc Kuzma (386)42535450 / kuzma@s5.net and he can explain everything to you about the zero switch box.
The electrical noise generated by the compressor when switching on, occures every few minutes and is similar to that which occures when a domestic refrigerator switches on. It is transfered via the mains not the air and can be solved by having a separate mains feed. If this is impossible or ineffective however, we have a "zero switch relay kit" which can be installed in the compressor and which normally solves the problem.

Franc Kuzma,www.kuzma.si

Thanks for the responses, gents. (Franc- you have been constantly responsive to me in the past, for which I thank you).
Interestingly, I had the compressor wired to a separate receptacle, connected via very high grade wire to a separate breaker in a separate subpanel from the subpanel which services the audio system power. That, alone, did not prevent the 'zap.'
I then plugged the compressor into an outlet on my 240v stepdown transformer, which seemed to reduce, but not entirely eliminate, the zap.
I then plugged my electronics- all of them- into an Shunyate Hydra, which, combined with the stepdown transformer hook up for the compressor, seemed to do the trick. But, I will contact Scot Markwell for this zero switch relay kit, since it will enable me to have a little more flexibility in how my components are hooked up. Regards,
Whart posts

I had the electrician come back and set up a separate line just for the compressor- having nothing to do with the system wiring or subpanel. (He had already pulled extra wire through the conduit up into the room, so it was no big deal to do this- he installed a high quality receptacle to this extra line, and terminated it at a different subpanel than that which runs the audio system).

(He had already pulled extra wire through the conduit up into the room, so it was no big deal to do this- he installed a high quality receptacle to this extra line,
>>

I must have missed your statement about pulling extra wires in the same conduit as the feeder, if I understand your statements correctly.

In your first posting of the thread you did not mention a correlation between the "zap" and the compressor cycling off and on. I would agree the contacts that control the compressor motor could indeed cause the pop noise heard through your audio system.

I believe one issue here is the fact the circuit that feeds the compressor motor, via relay contacts, is pulled in the same conduit as the audio sub panel feeder. Current carrying conductors installed in the same raceway, conduct, can interact with one another. A current carrying wire will have a magnetic field around it. Induced voltages, though small, will will cut across to other conductors within the same conduit. Think of it working kind of like a transformer. When the control circuit for the compressor commands the relay contact to close or open a transient voltage spike is sent out on the circuit wires feeding the compressor. Jmo the compressor motor feed should be installed in its own metallic conduit back to the main service electrical panel.
Jim
Gotcha. Makes sense. It zapped when fed by the regular old house circuit, which wasn't part of that conduit, but right now, the thing is quiet as a mouse when plugged into the 240v step down and having the system plugged into the Hydra.
The zero switch relay kit that is coming my way,, courtesy of the dealership, will hopefully eliminate the problem since I don't like running the extension cord to feed the compressor from the stepdown. (It is one of those big ugly yellow waterproof outdoor suckers- yyuuuck!)
So, Jea48, when are you going to send me a bill- or at least take a ride over and have a listen?
So, Jea48, when are you going to send me a bill- or at least take a ride over and have a listen?
>>>>>>>
I never charge a friend. Just glad to help a fellow Audio buff.
Jim