RCA -> XLR balanced line transmitter

[eRiCdWoNg]

...I know of only one thats commercially available thats somewhat affordable. its by ATI Audio called the matchmaker, and I think its about $200.

What I'm trying to do is feed a DJ mixer (that i havent bought yet) RCA output into my Ashly crossover (which is balanced, or unbalanced, but I like balanced and I'm sure I'll be using applications when the mixer is 50+ feet from the crossover).

So- I'm wondering if theres any schematic on the net or if anybody knows of here to build a balanced line transmitter from RCA to XLR. Or a cheaper alternative to the ATI audio one.

[koolscooby]

a quick search on google should give you some results... look for "audio matching transformer" ... i'd do this for youa nd find some good results but i'm just heading out ...
(I think this is what you'rel ooking for )

merry christmas!

[Steve Eddy]

Originally posted by eRiCdWoNg
...I know of only one thats commercially available thats somewhat affordable. its by ATI Audio called the matchmaker, and I think its about $200.

What I'm trying to do is feed a DJ mixer (that i havent bought yet) RCA output into my Ashly crossover (which is balanced, or unbalanced, but I like balanced and I'm sure I'll be using applications when the mixer is 50+ feet from the crossover).

So- I'm wondering if theres any schematic on the net or if anybody knows of here to build a balanced line transmitter from RCA to XLR. Or a cheaper alternative to the ATI audio one.

If you can find out how the outputs of the DJ mixer are configured, you can balance its output with just a couple of inexpensive passive parts.

Check out section 2.4 of this application note from Jensen:

http://www.jensentransformers.com/an/an003.pdf

se

[dhaen]

SSM2141 / DRV134

http://www.analog.com/Analog_Root/pr...SM2142,00.html

[trwh]

DI Box?

[eRiCdWoNg]

The DJ mixer market most of them are RCA although some are XLR out,
the more expensive mixers, I wonder why this is. Dj setups typically
use "pro audio" amps and other components.... Anyway I havent had good
experiences with unbalanced signals feeding my Ashly crossover, but
now I think about it it was probbly the cheap hosa cable I was using
before. Perhaps Ill buy some good quality cable this time, and try it
out. The Ashly should have enough gain to drive the power amps to
full potential. I also am looking at the mixer's tech specs and it
says main out max is +21 dBu (its a behringer, at least they have
products in the pro audio market better then gemini)

As for overdriving, one of my amps is a Crown Macro-Tech 5000Vz so I
sure hope I wont over drive that or I'll be over driving my ears =)
Hmmm, the mixers only $140 or so, it would seem silly to spend $100+
on parts to balance the signal coming out of a $140 mixer haha.
Unless I got nothin better to do with my time/money. Hmmmm..... ill
give it a whirl and see what happens.

[Aud_Mot]

The only reason you have to be distracted by all of this is IF you have a hum problem. Since you have not bought the equipment yet......

If you go to rane.com they have a wiring diagram that will show how to wire an RCA plug to an XLR (AKA cannon, microphone) connector. This was also covered in some previous diyaudio.com topics. One of them even had the rane diagrams posted.

I am sure that any DJ mixer has more than enough gain to overcome the 6dB you loose by going unbalanced instead of balanced. The main virtue of balanced is that it is more imune to hum and noise over a long run. In the context of your application, there is no sound quality improvement to be had going balanced line, as long as hum and noise is not present.

Inside of your cross over I would be willing to bet is unbalanced circuitry, 1/2 the circuit costs 1/2 as much to produce. You will not loose anything by giving your crossover a clean, noise free unbalanced signal.

If you do wish or need to run balanced, there is plenty of information in any opamp cookbook or application notes from any opamp manufacturer. Three NE5532 opamps, a box, some caps and resistors, some connectors and a power supply is all you need. Could be done for $20.00

It really all depends on the size of your wallet. Some people will tell you you need to spend $200.00 on cable. I have used Belden 9451 on very long microphone runs and it worked quite well. Buy the equipment you like, try it and if it is too noisey, then you can look for a balanced solution.

Enjoy,

Aud_Mot

[trwh]

What I'm trying to do is feed a DJ mixer (that i havent bought yet)

Woah! A B*hringer mixer and Ashly processing / Crown MA amps downstream? I think you have a budget mismatch here! I'd take a look at the Rane DJ mixers, or anything that has the proper balanced output 'natively', as this will put you into the right price range for your requirements. It sounds like you have some excellent PA equipment, and it would be a great shame not to support this with a decent source signal. B*hringer is _not_ the way to go.

Hope this helps, and good luck moving some earth with that 5000VZ!

Tim

<B*hringer and Macrotechs indeed, mutter mutter!>

[moamps]

Hi,

In electromagnetic noisy environment (clubs lights etc) the best way to me is using some sort of DI-box (1:1 ratio) witch isolate DJ console ground and amplifiers system ground and witch convert unbalanced signal to balanced (especially if those interconnects are longer than 1m or so). DI-box is connected with very short interconnects (10cm) to DJ console, and with some long balanced cable to amplifiers rack. I usually use Mogami cables, but any other brand will work, IMHO.

Regards

[eRiCdWoNg]

Originally posted by trwh


Woah! A B*hringer mixer and Ashly processing / Crown MA amps downstream? I think you have a budget mismatch here! I'd take a look at the Rane DJ mixers, or anything that has the proper balanced output 'natively', as this will put you into the right price range for your requirements. It sounds like you have some excellent PA equipment, and it would be a great shame not to support this with a decent source signal. B*hringer is _not_ the way to go.

Hope this helps, and good luck moving some earth with that 5000VZ!

Tim

<B*hringer and Macrotechs indeed, mutter mutter!>

Hahaha, the purpose of the behringer is actually to help me practice my DJing skills. Sound quality is important, but for a "beginner" setup I think its more then sufficient. Right now I'm using a Spirit F1 board and thats not exactly anything like a DJ mixer, with 2 Pioneer CDJ100S players.

Oh yeah, this is my "hobby" DJ system, so far the only use its gotten is a "favor" wedding and a huge house party I threw last friday. Maybe I will one day start charging $, but right now I'm just happy with the sheer power of a PA system.