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Discussion Starter · #1 ·
I just hooked up this unit to a new Behringer EP4000 and somethings amiss. I cannot turn the cleanbox's gain controls up beyond about 5% of the dials travel without hum and buzzing through both channels. If I stop just short of the interference point, I then have to turn up my processor sub gain to max to get any kind of output. Noise increases with gain control increase on the cleanbox only !
I have ruled out coax TV ground loop.

Another issue with this box - Switching off the power to it creates the worst turn off thump I've ever heard. By far the loudest I've gotten my subs was when I turned this thing off. I had it plugged into a sequential switching power supply, but no more - it is powered all the time !

Anyone out there have similar experiences with this box ?
 

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I have the samson s-convert which (afaik) is basically the same box. I also had that hum that most people associate with the tv cable box, yet i have no cable hooked up. What i did was went to radioshack and picked up some "cheater" plugs. The three prong to two prong adapters. Then just went through each device (htpc, ps3, receiver, eq2, s-convert, ect) and none of them fixed it. So tried it on the ep4000 itself and viola no more buzzing.

So if you can i'd go to a radioshack and pickup a cheater plug or two. I had to buy a two pack and i believe it was ~6 bucks. At least that way you can tell if it is a ground loop issue.


As for the thump....turn the ep4000 off first, then the box. I have no idea what causes it or anything just remember its just due to not turning devices off in the right order or something .
 

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Discussion Starter · #4 ·
Yes Velillin, i intend to try the cheater plug thing, hope it works.
I left the Cleanbox (not sure it is accurately named) plugged in full time and just switch the EP4000 on/off, which gives a very minimal thump, and i can live with that.

Jim, I have an Outlaw 950 processor, that feeds an Outlaw ICBM (basically a crossover/bass management/distribution unit. The ICBM has controls for subwoofer gain and they are maxed out, as is the processors gain control. I need to get rid of this buzzing so i can employ the gain on the ICBM !

Not sure what you mean by a "direct" box, but I needed the ART to convert the unbalanced from the Outlaw/ICBM to balanced on the EP4000.
 

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I think you should try it with RCA to XLR adaptors and eliminate the ART to see what the outcome is, you can pick the cables up way cheap at Monoprice.:T
 

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I run an EP2500, essentially the same amp, and the earlier Art Cleanbox.

I spent ages tracking down hum and used optic fibre in part of the signal chain. This fixed my earth loop problem, but introduced terrible noise when using the tuner. The culprit turned out to be the switch-mode plugpack on the cleanbox. Running it with a floatiing earth let the noise through. Moving to a transformer based plugpack fixed the issue. Just one more thing to consider.

Some guidelines on getting rid of earth loops here
 

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Discussion Starter · #7 ·
Bambino - Thanks, and no I have not tried that, and I should have before investing in the ART. I get Monoprice stuff all the time and in fact got the balanced cables for the Cleanbox from them - great company and realistic pricing !! (you know, i'm really having trouble calling this a "cleanbox" - so far it is anything but!)
Before the EP4000, I tried an EPX2000 and that experience told me i needed added gain !

Collo - Thanks for that info. I don't think i would have considered the wallwart to be an issue. I don't suppose you can remember the model transformer one you used ?
 

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Collo - Thanks for that info. I don't think i would have considered the wallwart to be an issue. I don't suppose you can remember the model transformer one you used ?
The model will be different here in Oz, but mine is 12VDC 150ma
 

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You can also use just RCA to RCA with a 1/4" TRS (i do believe...double check) adapter to hook into the ep4000 as well. Might be easier for a "quick shop" buy at a radioshack type store. Should only be a couple bucks and no shiiping :)

As for the thump...no clue but if you dont mind it then i'd call it good. I know turning on an doff my ep4000 i have no thump but i leave the s-convert and eq.2 on all the time. If i have the ep4000 on and turn off the eq.2 i get a nice loud thump
 

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Bambino - Thanks, and no I have not tried that, and I should have before investing in the ART. I get Monoprice stuff all the time and in fact got the balanced cables for the Cleanbox from them - great company and realistic pricing !! (you know, i'm really having trouble calling this a "cleanbox" - so far it is anything but!)
Before the EP4000, I tried an EPX2000 and that experience told me i needed added gain !
QUOTE]

I would think your AVR would have enough juice to push the EP:scratch: but i have been wrong like one other time in my life (LOL!). I think if you have the funds and don't get the issue worked out before your next order to Monoprice it would be worth the shot.:T
 

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Discussion Starter · #11 ·
Well, a cheater plug on the EP4000 reduced the humm enough so that I can dial in the gain i need before it starts again, so for now I'm good. Its not a total fix though, so I'm going to try a transformer plugpack eventually.
 

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collo;431568 Some guidelines on getting rid of earth loops [URL="http://www.subwoofer-builder.com/earth-loop.htm" said:
here[/URL]
Wow, thanks so much Collo. I just got a new EP4000 and while my new sub and amp sound great, that hum is unbearable. This is the first info I have seen where it breaks down this issue very simply. I have an Onkyo nr509 receiver, and from the sub pre-out I'm running a RCA->XLR cable to my EP4000. I'm pretty sure the Onkyo is 3 pronged(earthed) as is the EP4000. If I were to go into the RCA->XLR cable at the XLR end and disconnect the shield from the connector, this should fix my problem right?
 

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Thanks for those comments.

When you open the shield, bridge the gap with a 100ohm resistor and 100pf capacitor in parallel.

Let us know how you go.
 
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