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Post by jgsabato on Aug 31, 2006 12:29:31 GMT -7
Has anyone used this RCA to XLR / Unbalanced to Balanced Adaptor?
Right now, I am just using cables that are RCA to XLR (10 ft run) and while I do not have any problem driving the amp (Crown XLS-402), I do have a low level hum that is apparent when I get near the manifold outlet. I know there is a 14Db difference in levels between consumer and pro and the extra gain required may raise the noise floor.
Parts Express is within driving distance for me, so I can get one quickly. Any thoughts?
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Post by jagman on Aug 31, 2006 14:03:38 GMT -7
If they have a reasonable return policy then try it and find out.
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Post by ThomasW on Aug 31, 2006 14:26:00 GMT -7
Yep bought one a few weeks ago to interface between a friend's receiver and a Yamaha pro-sound amp. Did the job just fine...  |
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Post by jgsabato on Aug 31, 2006 18:11:48 GMT -7
Thanks Thomas. Guess I know what I am doing at lunch time tomorrow; Road Trip.  |
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Post by jgsabato on Sept 2, 2006 4:04:17 GMT -7
I hooked up the Clean Box and the hum got worse.  I then tried hooking up an old (25 yr + !) consumer power amp to see if there was something in the system inherently causing the hum. Result? Dead Silence, no trace of hum.  After scratching my head for a while, I figured I had a ground loop somewhere, but some of the old tricks did not seem to help. Finally, I noticed that the Crown power cord had a Grounding prong.....None of my other gear did. I tried a 3 prong to 2 prong adapter and did not connect the little flange to the grounding screw. That fixed the hum problem!  Thought I might pass this on since a lot of other board members are using Pro amps to power their subs. BTW, My site has been updated with initial measurements compared to what I had predicted. |
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Post by ThomasW on Sept 2, 2006 8:06:45 GMT -7
Most use the Cleanbox when they need to match levels between home and pro-sound gear, not to try and break ground loops. And as you've found sometimes the only thing that works for breaking ground loops is a cheater plug. I have several in my system.. |
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Post by chrisbee on Sept 2, 2006 23:08:23 GMT -7
European examples of the EP2500 don't have an earth pin. The same goes for my SVS. Do they have earth pins in the US?
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Post by jgsabato on Sept 3, 2006 4:18:29 GMT -7
Thomas, I did not buy the Clean Box to break a ground loop; The system had a low level hum before the Clean Box which was apparent onlywhen you stood above the manifold outlet. I thought that the 14 Db gain required to match levels amplified the noise as well as the signal (I did not have any trouble driving the amp). It was only after I added it that it could be heard somewhat at the listening position. I could probably return it and do without it, but having it allowed me to significantly cut back the Input level controls on the Crown and gives me more flexibility in setup overall, so I will keeo it in the system. It is pretty inexpensive anyway. Chrisbee, I cant comment specifically on the SVS or EP series amps, but what I have experienced in the last 30+ years of owning quite a bit of audio gear, is that in the US, consumer electronics tend not to have grounding plugs. None of the 22 consumer components (TV's VCR's. DVD Players, Tape decks, Recievers, power amps etc.) that I have today have ground plugs. All 3 PC's I own do use ground plugs, which makes sense until you consider that the 2 Hi Def TV's and 4 Satelite receivers (which really crank out some heat!) have really poweful single purpose computers built in. Go Figure. |
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Post by ThomasW on Sept 3, 2006 8:34:59 GMT -7
The bulk of my high-end and mid-fi gear over the last several decades has had 3 prong plugs. This includes Aragon, Ayre, Adcom power amps. Ayre and Sony pre-amps/processors. My Sony SCD-777ES has a 3 wire IEC connector.
I don't have a Behringer power amp but all my other Behringer gear, 1124P, FBQ2496, DEQ2496, CX2310, have removable IEC cords with 3 prong connectors
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Post by chrisbee on Sept 3, 2006 9:32:59 GMT -7
Interesting. Again the Behringr CX and BFD have only 2 pin plugs/sockets in Denmark.
All my Naim gear has 3 pin earthed plugs and sockets but that came form the UK. Where there is a long history of earthing via 13 Amp sockets and huge internally fused plugs.
Denmark, on the other hand, has a long history of not earthing and used dinky little 2 pin 10 Amp plugs and sockets fused at the CU/Fusebox until very recently.
The point I'm trying to get at (at last!) is why the same manufacturer's box should have diferent characteristics for different markets?
Either they are double insulated 2 pin (non-earthed) or they are not. So why earth a double insulated box? Oddly I notice the Behringer gear has no double insulated markings.
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Post by davepete on Sept 7, 2006 21:22:48 GMT -7
The bulk of my high-end and mid-fi gear over the last several decades has had 3 prong plugs. This includes Aragon, Ayre, Adcom power amps. Ayre and Sony pre-amps/processors. My Sony SCD-777ES has a 3 wire IEC connector. I don't have a Behringer power amp but all my other Behringer gear, 1124P, FBQ2496, DEQ2496, CX2310, have removable IEC cords with 3 prong connectors Does anyone know if the Cleanbox can be used to take an RCA preamp output, convert it to XLR, run that signal through a Behringer EQ, outputing the EQed signal via XLR, and pipe that back into the Cleanbox to convert back to RCA so I can feed a plate amp? In other words, I have a preamp RCA output I want to EQ via a processor with only XLR connectors, then feed to a plate amp with an RCA connector. Can one Cleanbox simultaneously handle both the RCA->XLR and XLR->RCA conversions necessary to accomplish this? If someone has the equipement to try this, I'd really appreciate it. Thx, Dave |
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Post by ThomasW on Sept 8, 2006 7:41:40 GMT -7
From reading the .pdf file it appears the Clean Box will do what you want
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Post by davepete on Sept 9, 2006 17:40:02 GMT -7
From reading the .pdf file it appears the Clean Box will do what you want Hmm, I didn't see a PDF doc on the Sweetwater website I was looking at. The usage instructions in that doc do appear to show it'll do what I need, though. Thanks for the assist, Thomas. Dave |
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johnvb
Junior Member
Posts: 71 
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Post by johnvb on Sept 16, 2006 20:15:03 GMT -7
The bulk of my high-end and mid-fi gear over the last several decades has had 3 prong plugs. This includes Aragon, Ayre, Adcom power amps. Ayre and Sony pre-amps/processors. My Sony SCD-777ES has a 3 wire IEC connector. I don't have a Behringer power amp but all my other Behringer gear, 1124P, FBQ2496, DEQ2496, CX2310, have removable IEC cords with 3 prong connectors Does anyone know if the Cleanbox can be used to take an RCA preamp output, convert it to XLR, run that signal through a Behringer EQ, outputing the EQed signal via XLR, and pipe that back into the Cleanbox to convert back to RCA so I can feed a plate amp? In other words, I have a preamp RCA output I want to EQ via a processor with only XLR connectors, then feed to a plate amp with an RCA connector. Can one Cleanbox simultaneously handle both the RCA->XLR and XLR->RCA conversions necessary to accomplish this? If someone has the equipement to try this, I'd really appreciate it. Thx, Dave Yes it can, as long as you are just using one channel for each. But doesn't the Behringer do the same, by itself? My old UltraCurve 8024' and my BFD offers balanced and unbalanced I/Os, the conversion is done electronically (instead of using a transformer), just like what is done in the Clean Box. What you would do is buy (or make) cables with RCAs on one end(to go into preamp), 1/4 phono on the other(to go into EQ) I used Cleanboxes in a setup such as what you are suggesting, but that was because there was a 50' cable run in-between EQ and amp. So I used a Cleanbox at each end. The cables I am using now with my BFD are DIY Star quads (4 conductors and a shield). I have rca connectors on one end, XLRs on the other. I know this isn't a balanced signal, the cable is short enough, doesn't need to be. I just like the way XLRs connect better than phono plugs. Works like a charm. |
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