# Behringer ADA8000 to convert Marantz 7007 RCA unbalanced to XLR Balanced for QSC RMX 850.



## AutoDelphi (Jul 23, 2014)

I am looking to amp my home theater with QSC PA style amps, the issue I am facing is converting the RCA amp pre out on my Marantz 7007 to a signal that is usable for the QSC amps. Looking to convert it to balanced XLR with the cleanest sound possible without any additional distortion. 

I have came across a Behringer ADA8000 Ultragain Pro 8-Ch A/D & D/A Converter. 

http://www.parts-express.com/behringer-ada8000-ultragain-pro-8-ch-a-d-d-a-converter--248-6020

Is this the best unit to use?? If not please steer me in the right product direction!!!


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## gazoink (Apr 17, 2013)

AutoDelphi said:


> I am looking to amp my home theater with QSC PA style amps, the issue I am facing is converting the RCA amp pre out on my Marantz 7007 to a signal that is usable for the QSC amps. Looking to convert it to balanced XLR with the cleanest sound possible without any additional distortion.
> 
> I have came across a Behringer ADA8000 Ultragain Pro 8-Ch A/D & D/A Converter.
> 
> ...



An A/D & D/A Converter isn't what you want. You'll need a device that converts unbalanced consumer levels to balanced pro levels, colloquially called a "match box", or "bump box". They run about $60 and up and handle stereo pairs in both directions, consumer to pro and pro to consumer. You only need consumer to pro, so half the box will go unused. The less expensive ones don't do the job quite as well as the expensive ones, but might be fine.

But a couple of questions: why the QSC Pro amps? Do you already own them? If not, there are less expensive, better matched amps for this purpose. The QSCs are great amps, and there's a chance you can connect them directly to your Marantz pre outs, crank the amp gains wide open, and you'll be fine. There's a possible level match issue, but not always. Can't find the Marantz specs to verify just now. 

All QSC Pro amps have cooling fans that are fairly noisy for home theaters. In fact, most pro amps of all brands have them.

Just to be clear, there's nothing to be gained by the use of balanced lines other than noise immunity. If your cables are short-ish, that's not a problem.


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## NBPk402 (Feb 21, 2012)

gazoink said:


> An A/D & D/A Converter isn't what you want. You'll need a device that converts unbalanced consumer levels to balanced pro levels, colloquially called a "match box", or "bump box". They run about $60 and up and handle stereo pairs in both directions, consumer to pro and pro to consumer. You only need consumer to pro, so half the box will go unused. The less expensive ones don't do the job quite as well as the expensive ones, but might be fine.
> 
> But a couple of questions: why the QSC Pro amps? Do you already own them? If not, there are less expensive, better matched amps for this purpose. The QSCs are great amps, and there's a chance you can connect them directly to your Marantz pre outs, crank the amp gains wide open, and you'll be fine. There's a possible level match issue, but not always. Can't find the Marantz specs to verify just now.
> 
> ...


I agree most Pro Amps are pretty noisy... My Yamaha P7000S is dead quiet though. :T


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## |Tch0rT| (May 2, 2013)

For pro amps you should consider Crown. The XLS and XTi series are known to be quiet (they're the only series I know for sure that are quiet). The fans only kick in when needed.

Then you need some RCA to XLR connectors:
http://www.zzounds.com/item--HOSXRM

You might not even need a bump box depending on the voltage output of the Marantz. My Tascam PA-R200 (rebadged Integra 30.4) doesn't need a bump box.


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## AutoDelphi (Jul 23, 2014)

Does anyone know the pre amp voltage output of the Marantz 7007? 

I previously tried using just some RCA to XLR connectors as |Tch0rT| suggested but the amp would not put out much sound!! I mean is sounded like a whisper.

I am not worried about how quite the amp itself is, they will be mounted in a room behind the theater room. What I was referring to was sound quality. I am planning on running the front mains on this amp and would like to confirm the amp had the same sound quality as the Marantz. 

I was fairly sure that we need a device to convert consumer ohm output to pro ohm input. 

This is the input Impedance for the amp:
Input Impedance	10k ohms unbalanced, 20k ohms balanced

What is the output Impedance of the Marantz 7007?? 

I was reading the RMX 850 has an Input Sensitivity @ 8 ohm 1.15V (+3.4 dBu). Does this mean the amp needs a signal of 1.15V to work efficiently? 

Also the amp has Input Clipping 10 Vrms (+22 dBu). What does this mean??


Thank you very much for all your help.


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## tcarcio (Jun 27, 2007)

I use the Rolls MB-15 and it works great. It bumps up the voltage of your pre outs so your amp will put out full power. Here is a link. http://www.googleadservices.com/pag...AB01%5E&nm=25&is=823x780&nx=326&ny=11&clkt=98


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## AutoDelphi (Jul 23, 2014)

tcarcio said:


> I use the Rolls MB-15 and it works great. It bumps up the voltage of your pre outs so your amp will put out full power. Here is a link. http://www.googleadservices.com/pag...AB01%5E&nm=25&is=823x780&nx=326&ny=11&clkt=98



How would you compare the Rolls to the CleanBox Pro? 
http://www.bhphotovideo.com/c/produ..._Directional_Level_Matching.html/prm/alsVwDtl

Also how would you say these converters effect sound quality? I am intending on using the amp to amp my front mains. I want to make sure that the speakers produce clean crisp un-distorted sound.


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## Wayne A. Pflughaupt (Apr 13, 2006)

AutoDelphi said:


> Does anyone know the pre amp voltage output of the Marantz 7007?


See Part 7 of my gain structure article for an easy DIY method to determine your AVR’s pre amp output voltage. You can find it at the link in my signature. As gazoink indicated, there’s a good chance you don’t need a signal booster.




> I previously tried using just some RCA to XLR connectors as |Tch0rT| suggested but the amp would not put out much sound!! I mean is sounded like a whisper.


If you are able to determine that your Marantz has sufficient output, then something was wrong with those cables. Either that or you had the per-channel levels set really low.




> I was fairly sure that we need a device to convert consumer ohm output to pro ohm input


Impedance isn’t the issue, signal voltage is.




> I was reading the RMX 850 has an Input Sensitivity @ 8 ohm 1.15V (+3.4 dBu). Does this mean the amp needs a signal of 1.15V to work efficiently?


It means that the amp can be driven to its maximum output with a 1.15v input signal. Virtually any AVR can generate more voltage than that.




> Also the amp has Input Clipping 10 Vrms (+22 dBu). What does this mean??


That’s the signal level that will make the amp clip. Nothing to worry about, few (if any) AVRs can generate a signal that hot.

Regards, 
Wayne


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## AutoDelphi (Jul 23, 2014)

Wayne A. Pflughaupt thank you for your reply.

What effect does input impedance play when connecting audio signals? The RMX850 has an imput impedance of 10k ohms unbalanced and 20k ohms balanced. 

How will this affect the sound/signal from my Marantz to the pro amp?

The spec sheet for the 7007 says the Digital D/A output is 2V @ 0dB playback. Is Marantz referring to the voltage output of the pre amp?

http://m.us.marantz.com/DocumentMaster/US/SR7007_0511.pdf


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## RTS100x5 (Sep 12, 2009)

DITTO the CROWN XLS amps are very powerful and quiet....

Parts Express also has RCA to XLR adapters

http://www.parts-express.com/xlr-male-to-rca-female-adapter--240-438


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## Wayne A. Pflughaupt (Apr 13, 2006)

AutoDelphi said:


> What effect does input impedance play when connecting audio signals? The RMX850 has an imput impedance of 10k ohms unbalanced and 20k ohms balanced.
> 
> How will this affect the sound/signal from my Marantz to the pro amp?


As far as I know it’s a non-issue; all modern audio electronics are compatible with each other, even when mixing consumer and pro gear. I can’t say I’ve ever heard of anyone having a problem with input/output impedances, and I’ve been trolling various home theater forums for 15 years, and reading audio enthusiast publications even longer.




> The spec sheet for the 7007 says the Digital D/A output is 2V @ 0dB playback. Is Marantz referring to the voltage output of the pre amp?


 Can’t say that I’ve ever heard of that particular specification. I’d strongly recommend doing the voltage-output test I suggested in my previous post to see what you’re really getting from the 7007’s pre amp outs.

Regards, 
Wayne


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## RTS100x5 (Sep 12, 2009)

I have a Marantz 6008 driving an Emotiva XPA 3 .. Its an Excellent combo


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## waculjr.903 (May 27, 2009)

I have a QSC RMX 2450 and it is dead quiet. If you are clean at your sources that is the question . If you use cheap gear period, don't expect to get audiophile results. The best path to take is to sell what you have, and purchase a Marantz 8003, or a 7005 that already have XLR outputs to strait up jack from pre pro to your pro audio amps. That is your best bet, nice and clean. There can be additional distortion and noise introduced into your setup with these cheapie converters. There is a good one , but it is cheaper and better to go the route above stated! Hope this helps you! Good luck!


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## Wayne A. Pflughaupt (Apr 13, 2006)

Keep in mind that most home audio signal sources are not balanced, which means the pre-amp has to convert everything to balanced if it has balanced outputs. IOW, more “stuff” in the signal chain, just as if an outboard converter device were used.

Regards,
Wayne


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## waculjr.903 (May 27, 2009)

Has anyone checked if it is or is not? I wouldn't believe that Marantz would do it in the cheapie fashion. Either way, it is clean, plenty of power , good headroom, not lacking for power in the pro amps. Thats kind of like comparing bargain basement to some good quality gear. I personally wouldn't touch those cheap converters like Sampson s convert or art clean box for main channels. Sure they are sufficient for squeezing some serious juice to a subwoofer, but no sir, not to my mains! It always comes out to this same debate. It would be nice if someone could really clear up what manufactures and what models of pre pros are truly balenced!


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## waculjr.903 (May 27, 2009)

Besides signal is what it is. When it hits the Marantz, or Anthem, krell etc. I would imagine that everything that goes thru its processors and out to the amps is nothing but purity in sound. Otherwise no one would even think of ponying up that much cash for a second rate central point of sound!


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## waculjr.903 (May 27, 2009)

If you really want a converter that is clean, Apex makes one with eight channels. It costs $850, and is as clean as it comes! .001 THD!!!


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## waculjr.903 (May 27, 2009)

I went to Guitar Center looking at Behringer stuff, the Employees there did not think to highly of that brand of gear. All in all, you usually get what you pay for. I tried that route before, never again!


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## waculjr.903 (May 27, 2009)

About a year ago, I did an experiment. I was using the Emotiva XPA 5 and I thought " I wonder what it would be like to hook up my Integra pre pro directly using XLR cables, to my QSC Amp to run my mains with?" So thats exactly what I did. SWEETNESS!!!!!! Wow! Now that was some good quality sounding stuff ! I tried radio, cd, then bluray movies. I was very impressed! It is like they woke up sonically. Clear as a bell, imaging was more defined, and yes the same listening level. Either way I know what I would do... The choice is yours. Good luck in your endeavor of sound, and good day !


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## Wayne A. Pflughaupt (Apr 13, 2006)

waculjr.903 said:


> Has anyone checked if it is or is not? I wouldn't believe that Marantz would do it in the cheapie fashion.


Not saying the conversion isn’t be done well in the receivers, just sayin’ it’s more stuff in the signal chain. That kind of stuff bothers some people – me, not so much.

I’ve heard people report that the S-Convert was actually a pretty decent piece of gear. Assuming a converter/booster’s TDH is low and response is linear, the main issue is really the signal boosting itself. That’s where the noise comes from (at least in the main channels).




> It would be nice if someone could really clear up what manufactures and what models of pre pros are truly balenced!


You bring up another good point that I almost mentioned in my previous post: From what I understand, some consumer pre amps with balanced outputs aren’t truly balanced, at least not by pro-audio standards. Don’t recall what the exact issue with them is, though…




waculjr.903 said:


> If you really want a converter that is clean, Apex makes one with eight channels. It costs $850, and is as clean as it comes! .001 THD!!!


A cheaper way to convert the signal is to use something like an outboard equalizer, crossover, etc. Any piece of equipment like that (with balanced ins and outs) will deliver a balanced output with an unbalanced input.

Regards,
Wayne


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## waculjr.903 (May 27, 2009)

Or a mixing board ?


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## Wayne A. Pflughaupt (Apr 13, 2006)

Sure enough...










Regards,
Wayne


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## AutoDelphi (Jul 23, 2014)

[/QUOTE]

A cheaper way to convert the signal is to use something like an outboard equalizer, crossover, etc. Any piece of equipment like that (with balanced ins and outs) will deliver a balanced output with an unbalanced input.

Regards,
Wayne[/QUOTE]

Do you have any suggestions on brands of equalizers, crossovers or like wise? I am looking for best value, I dont feel the need to overly spend yet I want good results? I know this is the impossible dream, so what would give me the best bang for the buck in terms of sound quality. 

Please keep in mind the unit should have the capabilities to increase line voltage as well. 

Thank you for you help!!


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## NBPk402 (Feb 21, 2012)

I believe the Beringer Feedback Destroyer will do it... At least I hope it will, as i just purchased one. They can be found for as little as $50 used, and used to help EQ your sub too.


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## Wayne A. Pflughaupt (Apr 13, 2006)

AutoDelphi said:


> Do you have any suggestions on brands of equalizers, crossovers or like wise? I am looking for best value, I dont feel the need to overly spend yet I want good results?


Can’t go wrong with the vintage Yamaha YDP2006. It can provide a limited amount of signal boost, although you have to keep in mind that this will come with a noise penalty. The Feedback Destroyer is fine for subwoofer use, but I wouldn’t recommend it for the main channels, and it does no signal boosting aside from what may come with the filters used.

While electronic crossovers typically have provisions for signal boost, you probably would not want to use one unless you intend to utilize its frequency-dividing capabilities. They don’t work well solely as signal boosters because they don’t have full-range outputs.

Regards, 
Wayne


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## RTS100x5 (Sep 12, 2009)

A cheaper way to convert the signal is to use something like an outboard equalizer, crossover, etc. Any piece of equipment like that (with balanced ins and outs) will deliver a balanced output with an unbalanced input.

Regards,
Wayne[/QUOTE]

Do you have any suggestions on brands of equalizers, crossovers or like wise? I am looking for best value, I dont feel the need to overly spend yet I want good results? I know this is the impossible dream, so what would give me the best bang for the buck in terms of sound quality. 

Please keep in mind the unit should have the capabilities to increase line voltage as well. 

Thank you for you help!![/QUOTE]

http://www.parts-express.com/behringer-dcx2496-ultradrive-pro-digital-24-bit-96-khz-loudspeaker-management-system-cros--248-669


Internal switch-mode power supply for flexibility (100 - 240 V) and noise-free audio
Adjustable delays for all inputs/outputs allow correction for arrival time differences
Four different mono and stereo output operating modes
Butterworth, Bessel and Linkwitz-Riley filters with slopes from 6 to 48 dB/octave
Link option via RS-485 network interface enables cascading of several Ultradrive Pros
60 user-defined internal presets storable via PC software or on PCMCIA card


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## MetropolisLake (Sep 22, 2014)

I just came off of a QSC RMX 2450. I'm sending it back, luckily the vendor is being nice so I'm jumping on it. I did use the CleanBox Pro to bump the output up. It simply did not work out. Had sub outs of a Marantz SR-7009 cranked up to 12 which is maxed out, had the cleanbox cranked up to 10 which is maxed out, and unless I was watching Transformers, which could be +10 gain on the amp, I had to crank the gain on the amp up all the way. The fan was horrible, 5 times louder than my new Behringer iNuke. It heated my room if the doors were closed. It made my subs sound mushy to put it lightly. 

Upgraded to a new iNuke 6000 and I'm getting huge slam. Very happy with the switch. If anybody's experience sounds anything like what I just typed I would recommend dumping the QSC on eBay and starting over.


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## AutoDelphi (Jul 23, 2014)

MetropolisLake said:


> I just came off of a QSC RMX 2450. I'm sending it back, luckily the vendor is being nice so I'm jumping on it. I did use the CleanBox Pro to bump the output up. It simply did not work out. Had sub outs of a Marantz SR-7009 cranked up to 12 which is maxed out, had the cleanbox cranked up to 10 which is maxed out, and unless I was watching Transformers, which could be +10 gain on the amp, I had to crank the gain on the amp up all the way. The fan was horrible, 5 times louder than my new Behringer iNuke. It heated my room if the doors were closed. It made my subs sound mushy to put it lightly.
> 
> Upgraded to a new iNuke 6000 and I'm getting huge slam. Very happy with the switch. If anybody's experience sounds anything like what I just typed I would recommend dumping the QSC on eBay and starting over.


Did you still need to use the clean box pro with the iNuke 6000? I am currently using the the CleanBox Pro with my Behringer EP2500 and I am getting a hummm from it. Not sure if its the amp of the CleanBox Pro. 

Please let me know if you needed the CleanBox with the iNuke 6000.

Thank you


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## MetropolisLake (Sep 22, 2014)

AutoDelphi said:


> Did you still need to use the clean box pro with the iNuke 6000? I am currently using the the CleanBox Pro with my Behringer EP2500 and I am getting a hummm from it. Not sure if its the amp of the CleanBox Pro.
> 
> Please let me know if you needed the CleanBox with the iNuke 6000.
> 
> Thank you


No, I don't need it. Right now I have the subs boosted on the receiver and when it hits the iNuke, turning the gain halfway up is all I need if I have both channels going. Boosting the gain to 3/5 of the way is pretty bass heavy. 3/4 of the way up and I will throw breakers even at low volume on my other speakers. I have not tried it with the sub output turned down on the receiver, but I have yet to meet anybody who says they need one of these things with an iNuke. The 3000 is very popular, and actually a 6000 is just two 3000's in bridge mode, and I haven't heard anybody using a cleanbox and a 3000. Everybody just takes those XLR male to RCA female adapters, which basically just drops the ground, and it plugs right up. I haven't even read the manual or messed with the setup either, might could tweak things there even more.


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## WooferHound (Dec 8, 2010)

Those QSC amps should have 1/4 inch inputs as well as the XLR. You will get the best results by using RCA to 1/4 inch cables and avoid the XLR connections.


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