2. analog
  3. 1148743762

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.
128x128whart
whart's avatar
whart OP
3,037 posts
 
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.
limsp
1 posts
 
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.
qzm
1 posts
 
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
whart's avatar
whart OP
3,037 posts
 

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,
jea48
4,423 posts
 
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
More to discover