A potential problem just occurred to me about where I have installed AC Switch Panel. I have it installed 2" directly below the rest of my rack gear, and about 5" above my mixer (as seen in this picture 
- it's the black rack w/ red switches).
What I didn't consider before was if it would cause any interference to the equalizer rack only 2" above it, or any of the gear above that.. or for that matter to the mixer below it..
Should I consider repositioning it somewhere else, or is it ok where it's at?
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Also another puzzling situation...
XLR CONNECTIONS:
In mention of the equalizer:
I thought all XLR connections were balanced!
On the back of my equalizer:
--It has a clearly marked "Balanced Input" inside a single white square surrounding both the 1/4 jack input and the XLR input.
--And the output marked "Unbalanced Output" with a single white square surrounding both the 1/4 and XLR outs.
It sure appears to say that both the XLR and the 1/4 outputs connectors are unbalanced outs... but how can that be if all XLR connections are balanced?
And the manual confirms this:
9. Input/Output Connectors
Balanced XLR and 1/4” TRS Inputs and unbalanced output jacks for line level operation. Line level signals from - 18dBu to +18dBu are considered normal.Note: Only one input and one output connector should be used at a time.
and in the specs:
OUTPUTS:
Type
Unbalanced
Connectors
3-Pin XLR, 1/4” TRS
Again, it says that XLR connection is unbalanced
I am sending this eq back..
I recently came to realize it does not have all the features and connection types that were described in the auction, and the picture even was also different.
Since they didn't post the correct info or pics, they have emailed me a paid UPS return label with offer of a full refund - even though I no longer have the original box and have already mounted it (this is a new unit). They realize this but will still accept a return since their description and images were inaccurate.
Any suggestions on what equalizer I should look for to replace it?
A what happened to the 'rule' of all XLR connections being balanced?
I would think, now that I think about it...you have a potential for something else...unless you have already accounted for it...that would be having all this stuff properly grounded by way of the chassis and each piece of equipment.
Normally rack mount stuff is bolted to metal rails even if the cabinet itself is of wood construction...as yours is. You have the gear bolted to a wood railing on each side. For that reason...yes I would be concerned about a "click...pop" potential from inrush as the switches are operated.
Maybe put that somewhere in the back, away from everything, then fed by a master touch on/touch off low voltage DC level circuit controlling a relay that does the actual main AC power switching feeding that multi-switch unit.
Just remember to have the individual equipment's power switches on either way you go...don't want to be flipping on and off switches wondering why stuff is not turning on! I have seen that happen too!! LOL
As to the EQ thing...only non-balanced XLR i have ever head of is one where someone purposely made it non-balanced by wiring it that way. Well as far as a replacement....try a music shop or keep hunting on ebay for a decent one.
RFB
Disclaimer
The views and opinions expressed here in this reply do not necessarily represent the views and opinions of Part 15.us, its management, owners, staff, the birds and the bees, jelly beans and pumpkin seeds, apples and pineapples, oranges and lemons, or any other member of Part 15.us information-idea-opinion exchange forums and blogs. The reply represents ONLY the author's and do not necessarily declare as the be all end all....read at your own discretion!!
I would think, now that I think about it...you have a potential for something else...unless you have already accounted for it...that would be having all this stuff properly grounded by way of the chassis and each piece of equipment.
Normally rack mount stuff is bolted to metal rails...yes I would be concerned about a "click...pop" potential from inrush as the switches are operated.
Is that the only concern?; the "click pop" only when the power switches are turned on?.. that doesn't seem too worrisome to me. I was concerned about a potential increase of the noise floor in general.
I would rather not move it if it's not necessary. But if it is a problem, would grounding the units together with some copper wire or something do the trick? what would I ground it to?
By the way, concerning the unbalanced XLR on my equalizer, I emailed the Nady tech support...
Hello,
I need some clarification on a particular specification on the output of this equalizer.
I bought one of your GEQ 131 31 Band Graphic Equalizers from a dealer on ebay.. I now notice you have three different GEQ 131's, -the one I received is the single rack unit that does not have the round dials on the front, and is currently featured on your website in the picture on that page.
Long story short, I bought one, but the seller was showing the specs and picture of a earlier model 131, and I have been provided the option to send it back to them for a full refund..
However, if the one I have will serve my purpose then I would just assume work with the one I already received, but here's what I don't understand...
In your manual it states that the XLR output connection on the GEQ 131 is "Unbalanced".. but it has been my understanding that all XLR connections are always, in all cases "balanced".
So, am I misinformed, or are specs stating the XLR output as unbalanced in this specific model GEQ-131 a misprint?
Please confirm with certainty whether the XLR output of this equalizer is Balanced or Unbalanced.
Thank you for your time, and awaitng your reply,
Richard Powers
[email protected]
Is that the only concern?; the "click pop" only when the power switches are turned on?.. that doesn't seem too worrisome to me. I was concerned about a potential increase of the noise floor in general.
Well this is why I mentioned about the chassis of each piece of gear above the AC cluster switch unit. That switch unit appears to be of the type that has integral "click-pop" filtering on the switch contacts, usually just a .1mfd capacitor across the contacts to absorb any switch contact sparking, which without that filtering would induce clicks and pops.
Let's say your on the air and have a piece of equipment not powered up via that AC switch box. While a song or other is playing, you need to fire up say..the reel to reel. You reach for its power switch on the AC switch cluster. If you do not hear any click-pop on the air chain and off air monitor, or spike indication on your metering, your fine. If you do...then you got a problem.
To help reduce any possibility of that happening, simply run a 1/4 inch wide copper strap on both sides of the equipment behind their mounting ears and then attach those copper straps to station/studio ground.
There isn't anything above it that would have a high order of input gain, like a rack mounted mic mixer would, which would have more of a chance of picking up induced click-pop from that AC switch array. And there appears to be enough separation from it and the mixer area below, and also from the looks of it, your routing the mic cable to the left of that so it will be away from that AC switch box. So ya other than the click pop thing...you should be fine..but I would indeed run that 1/4 copper strap on each side of those rack mounted stuff and run that to station/studio common ground. Should be fine in my opinion.
RFB
Disclaimer
The views and opinions expressed here in this reply do not necessarily represent the views and opinions of Part 15.us, its management, owners, staff, the birds and the bees, jelly beans and pumpkin seeds, apples and pineapples, oranges and lemons, or any other member of Part 15.us information-idea-opinion exchange forums and blogs. The reply represents ONLY the author's and do not necessarily declare as the be all end all....read at your own discretion!!
To help reduce any possibility of that happening, simply run a 1/4 inch wide copper strap on both sides of the equipment behind their mounting ears and then attach those copper straps to station/studio ground.
You mean the electrical ground?.. I mean, what do you mean by the station/studio ground?
The ground I refer to is commonly known as "Technical Ground", this is an isolated ground path not of the electrical ground. However as with any 3 prong equipped device, the chassis is usually tied to the electrical ground, which is in fact an earth ground.
Reviewing my write up on my CC system and its interface to the breaker box, we see that NEC codes call for isolated neutral return and earth ground. The earth ground is where that third prong connects via the electrical socket. This is good! It will provide you with that extra ground path, and should be adequate for the purpose of your setup.
I was just throwing out the idea of adding an extra layer of ground for your equipment. This extra layer of ground would also be its own ground system, isolated from both the electrical ground and the ground you use on your antenna system. It would comprise of another ground rod into the dirt, and attached would be either a good solid copper wire, or a ground strap and run into your studio. Then by adding the 1/4 inch wide ground copper strapping, or even just a wire, tie that to this extra layer of ground.
This is a common practice in studio settings such as recording studios and even radio studios to prevent static buildup, as most facilities will have carpet on the floor. And under certain conditions, static charge can build up and if you touch something metal, such as a door knob or other non-grounded metal surface, ZAP! The extra layer of ground helps prevent this.
You should be fine with just the standard ground provided through the 3 prong power plugs. But if you encounter any static buildup and get that irritating zap when you touch something metal on your studio setup...then you should consider this extra grounding layer.
RFB
Just an update on the strange unbalanced XLR connection of the equalizer. The following is the reply I got from the Nady company:
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From: David Gravereaux [mailto: [email protected]]
> Sent: Thursday, March 10, 2011 3:07 PM
> Subject: GEQ-131 Equalizer - clarification on out put please
The output is unbalanced. Pin 3 is driven and in opposite polarity to
pin 2, but it doesn't float and is not by definition quasi-balanced
(also known as cross-coupled).
IOW, when unbalancing by tying pin 3 to ground at the next input, you
lose 6dB of differential level and are shorting that end's output amplifier.
In a studio situation when bringing it to a patchbay, it would be best
to treat it as unbalanced and ignore pin 3 altogether.
See connection 3b @ http://www.rane.com/note110.html
Yes, we are aware that this is strange.
--
David Gravereaux
New Products Technician
Nady Systems, Inc.
Emeryville, CA
Well that is a surprise...a fake balanced xlr from the factory.
Makes you wonder what else in that thing is faked too...specs perhaps? S/N ratios? Freq response? Hum and noise?
Dunno but that reply you got does not sound very comforting just over the xlr issue.
RFB
Well, it doesn't matter, I sent it back today with the prepaid UPS shipping label they emailed me, and I'm to get a full refund once they receive it = $65.99.. I guess you get what you pay for.
I guess I didn't really have need a 31 band equalizer anyway, but for a factory new eq, the price sounded like a bargain.
This time I'm looking at used ones on ebay.. trying to snag another "bargain".. can only hope it'll be right this time.